Richard E. Nisbett - Intelligence and How to Get It_ Why Schools and Cultures Count (2009, W. W. Norton & Company).pdf - PDFCOFFEE.COM (2024)

Intelligence A N D H O W T O GET IT Why Schools and Cultures R I C H A R D E. NISBETT

W. W. N O R T O N & C O M P A N Y New York • London

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C o p y r i g h t €> 2 0 0 9 by R i c h a r d K. Nisbett A l l r i g h t s reserved P r i n t e d i n t h e U n i t e d Stares o f A m e r i c a First E d i t i o n For i n f o r m a t i o n a b o u t permission t o r e p r o d u c e selections f r o m this b o o k , w r i t e t o Permissions, W . W . N o r t o n 6 c C o m p a n y , Inc., 5 0 0 Fifth Avenue, New York, NY 10110 F o r i n f o r m a t i o n a b o u t s p e c i a l d i s c o u n t s f o r b u l k p u r c h a s e s , please c o n t a c t W . W . N o r t o n S p e c i a l Sales a t s p e c i a l s a l e s @ w w n o r t o n . c o m o r 8 0 0 - 2 3 3 - 4 8 3 0 M a n u f a c t u r i n g by Courier Westford Book design by C h a r l o t t e Staub Production manager: Anna Oler L i b r a r y of Congress Catalogmg-in-Publication Data Nisbett, Richard K. I n t e l l i g e n c e a n d h o w t o get i t : w h y s c h o o l s a n d c u l t u r e s c o u n t / R i c h a r d E. N i s b e t t . — 1st e d . p. c m . Includes b i b l i o g r a p h i c a l references a n d i n d e x . ISBN 978-0-393-06505-3 (hardcover) I. Intellect 2. Intelligence 3. Schools. 4. C u l t u r e . I. Title. BF431.N57

2009

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2008044477

W . W . N o r t o n 6 c C o m p a n y , Inc. 5 0 0 Fifth Avenue, N e w Y o r k , N . Y . 10110 www.wwnorton.com W. W. N o r t o n 6c Company Ltd. Castle H o u s e , 7 5 / 7 6 W e l l s Street, L o n d o n W I T 3 Q T 12 3 4 5 6 7 8 9 0

For LEE R O S S

CONTENTS

Acknowledgments

ix

1

Varieties of Intelligence

2

Heritability and Mutability

3

Getting Smarter

4

Improving the Schools

5

Social Class and Cognitive Culture

6

IQ in Black and White 93

7

Mind the Gap

8

Advantage Asia?

9

People of the Book

10 EPILOGUE

APPENDIX A APPENDIX B

i 2.1

39 57 78

119 153 171

Raising Your Child's Intelligence . . . and Your O w n 182. What W e N o w Know about Intelligence and Academic Achievement 193 Informal Definitions of Statistical Terms

201

The Case for a Purely Environmental Basis for Black/White Differences in IQ 2 0 9 Notes

2.37

References 2.57 Credits Index

Z83 2.85

ACKNOWLEDGMENTS

and some of the research reported in it, was supporred by the Narional Science Foundation under Grant N o . 0717982 and by the National Institute on Aging under Grant N o . I R O l AG029509-01A2. Neither agency should be assumed to endorse the views represented in the book. The psychology department of Columbia University and the Russell Sage Foundation contributed valuable resources and facilities.

THE WRITING OF THIS B O O K ,

Many people generously provided ideas and criticism that improved this book—though none of them is responsible for any errors in it. These people include Joshua Aronson, Douglas Besharov, Clancy Blair, Jeanne Brooks-Gunn, Hannah Chua, William Dickens, James R. Flynn, Phillip G o f f , Richard Gonzalez, David Grissmer, Diane Halpern, Lawrence Hirschfeld, Earl Hunt, Shinobu Kitayama, Matt M c G u e , Walter Mischel, Randolph Nesse, Dan Osherson, Daphna Oyserman, Denise Park, Richard Rothstein, Peter Salovey, Kenneth Savitsky, Fldward E. Smith, Jacqui Smith, Claude Steele, Robert Sternberg, Eric Turkheimer, Barbara Tversky, Jane Waldfogel, and Oscar Ybarra. I am grateful to my agents, John Brockman and Katinka Matson, for representing me and for facilitating the public's access to scientific writing. I thank my editors—Angela von der Lippe, Erica Stern, and Mary Babcock—for excellent work in bringing the manuscript to publication. Laura Reynolds provided assistance in preparing the manuscript. Katherine Rice provided invaluable help in the form of library research and vigorous and construc-

X

ACKNOWLEDGMENTS

tive criticism. Susan Nisbett made excellent suggestions and provided sage advice. Lee Ross contributed to this book, as he has to all my other projects since 1 first met him in graduate school. For his intellectual stimulation and his friendship, this book is dedicated to him.

Intelligence H O W T O G E T IT

CHAPTER ONE

Varieties of Intelligence By intelligence the psychologist /means) inborn, all-around intellectual ability . . . inherited, not due to teaching or training . . . uninfluenced by industry or zeal. — S i r C y r i l Burt and colleagues (1934)

with arithmetic in the fifth grade, after I missed school for a week just when my class took up fractions. For the rest of elementary school I never quite recovered from that setback. My parents were sympathetic, telling me that people in our family had never been very g o o d at math. They viewed math skills as something that you either had or not, for reasons having mostly to do with heredity. I BEGAN HAVING TROUBLE

My parents probably were not aware of the psychological literatLire on the question of intelligence, but they were in tune with it. M a n y if not most experts on intelligence in the late twentiethcentury believed that intelligence and academic talent are substantially under genetic control—they are wired in and more or less unfold in any reasonably normal environment. Such experts were suspicious about the likely success of any effort to improve intelligence and were not surprised when interventions such as early childhood education failed to have a lasting effect. They were quite dubious that people could become smarter as the result of improvements in education or of changes in society. But the results of recent research in psychology, genetics, and neuroscience, along with current studies on the effectiveness of 1

2

I N T E L L I G E N C E A N D H O W T O GET I T

educational interventions, have overturned the strong hereditaria!! position on intelligence. It is now clear that intelligence is highly modifiable by the environment. Without formal education a person is simply not going to be very bright—whether we measure intelligence by IQ tests or any other metric. And whether a particular person's IQ—and academic achievement and occupational success—is going to be high or low very much depends on environmental factors that have nothing to do with genes. There are three important principles of this new environmentalism: 1. Interventions of the right kind, including in schools, can make people smarter. And certainly schools can be made much better than they are now. 2. Society is making ever greater demands on intelligence, and cultural and educational environments have been changing in such a way as to make the population as a whole smarter—and smart in different ways than in the past. 3. It is possible to reduce the IQ and academic achievement gap that separates people of lower economic status from those of higher economic status, as well as the gap between the white population and some minority groups. The basic message of this book is a simple one about the power of the environment to influence intelligence potential, and more specifically about the role that schools and cultures play in affecting the environment. The accumulated evidence of research, much of it quite recent, provides good reason for being far more optimistic about the possibilities of actually improving the intelligence of individuals, groups, and society as a whole, than was thought by most experts even a few years ago. On the other hand, just as there are laypeople and experts who are wrongly convinced that intelligence is mostly a matter of genes, there are laypeople and experts who have mistaken and sometimes overly optimistic ideas about the sorts of things that can improve intelligence and academic performance. One of the

Varieties

of Intelligence

3

goals of this book is to present evidence on which interventions are most effective. The chapters that follow emphasize that societal and cultural differences among groups have a big impact on intelligence and academic achievement. People of lower socioeconomic status have lower average IQs and achievement for reasons that are partly environmental—and some of the environmental factors are cultural in nature. Blacks and other ethnic groups have lower IQs and achievement for reasons that are entirely environmental. Most of the environmental factors relate to historical disadvantages but some have to do with social practices that can be changed. Culture can also confer advantages for the development of intelligence and academic achievement. Some cultural groups have distinct intellectual advantages, on average, over the mainstream white population. These include people with East Asian origins and Ashkenazi Jews. Later, I discuss what these advantages are due to and whether some of them might be adopted by others who would like to increase their own intelligence and academic achievement. Finally, I present ways of improving intelligence as suggested by new scientific findings. Nearly everything in this book is readily understood without any particular technical knowledge. But it might be helpful to be familiar with statistics, so I provide an appendix defining some terms. Readers who want to brush up on their statistics might also want to look at the appendix. The concepts discussed there are normal distribution, standard deviation, statistical significance, effect size (in standard deviation terms), correlation coefficient, self-selection, and multiple-regression analysis. Note that I have a somewhat atypical aversion to multipleregression analysis, in which a number of variables are measured and their association with some dependent variable is examined. Such analyses can give a false impression of the degree to which causality can be inferred, and I refer to them only rarely and always with skepticism. Those of you who would like to see the basis of my prejudice can look at the part of Appendix A that deals with it.

4

I N T E L L I G E N C E A N D H O W T O GET I T

To get us started, in this chapter I define intelligence, discuss how it is measured, present evidence on the two different kinds of analytic intelligence assessed by IQ tests, and discuss the types of intelligence not measured by IQ tests. I also examine how well IQ predicts academic achievement and occupational success, the types of intelligence not tapped by IQ, and important aspects of motivation and character.

Defining

and

Measuring

Intelligence

A definition of intelligence by Linda Gottfredson is a good place to start: [ I n t e l l i g e n c e is| a v e r y general mental c a p a b i l i t y that, a m o n g o t h e r things, i n v o l v e s the ability to r e a s o n , plan, s o l v e p r o b l e m s , think abstractly, c o m p r e h e n d

complex

ideas,

learn

q u i c k l y and

learn

f r o m e x p e r i e n c e . It is n o t m e r e l y b o o k learning, a n a r r o w a c a d e m i c skill, or test-taking smarts. R a t h e r it reflects a b r o a d e r and deeper capability

for comprehending our surroundings—"catching on,"

" m a k i n g s e n s e " o f things, o r " f i g u r i n g o u t " w h a t t o d o .

Experts in the field of intelligence agree virtually unanimously that intelligence includes abstract reasoning, problem-solving ability, and capacity to acquire knowledge. A substantial majority of experts also believe that memory and mental speed are part of intelligence, and a bare majority include in their definition general knowledge and creativity as well. These definitions leave out some aspects of intelligence that people in other cultures would be likely to include. Developmental psychologist Robert Sternberg has studied what laypeople in a large number of cultures think should be counted as intelligence. He finds that a good many people include social characteristics, such as ability to understand and empathize with other people, as aspects of intelligence. This is especially true of East Asian and African cultures. In addition, East Asian understanding of intelligence emphasizes the pragmatic, utilitarian aspects more than Western views do,

Varieties

of

Intelligence

5

which are more likely to value the search for knowledge for its own sake, whether or not it has any obvious immediate uses. Intelligence is often measured by IQ tests. The Q, by the way, stands for quotient. The original IQ tests, which were devised for schoolchildren, defined intelligence as mental age divided by chronological age. By that definition, a ten-year-old with a test performance characteristic of twelve-year-olds would have an IQ of i 2.0; one with a mental age typical of eight-year-olds would have an IQ of 80. But modern IQ tests arbitrarily define the mean of the population of a given age as being 100 and force the distribution around that mean to have a particular standard deviation—usually 15. So a person whose performance on the test was one standard deviation above the mean for his or her age group would have an IQ of 115. To give you an idea of what an IQ difference of 15 points means, a person with an IQ of 100 might be expected to graduate from high school without much distinction and then attend a year or two of a community college, whereas a person with an IQ of 1 1 5 could expect to graduate from college and might go on to become a professional or fairly high-level business manager. In the other direction, someone with an IQ of 85, which is at the bottom of the normal range, is a candidate for being a high school dropout and could expect a career cap of skilled labor. Although IQ tests were designed to predict school achievement, it quickly became apparent that they were measuring something that overlaps substantially with ordinary people's understanding of what intelligence is. At any rate, people's ratings of other people's intelligence correlate moderately well with the results of IQ tests. Those who are rated higher in intelligence by ordinary people also get higher IQ test scores. There are a huge number of IQ tests, but there is not much difference among the reasonably comprehensive ones, and the typical correlation between any t w o tests, even those having rather different apparent content, is in the range of .80 to .90. Tests of intelligence sometimes measure quite specific skills such

6

I N T E L L I G E N C E A N D H O W T O GET I T

as spelling ability and speed of reasoning. Such highly specific tests tend to correlate with one another in clusters. For example, tests of memory tend to be correlated. The same is true for tasks measuring visual and spatial perception of various kinds (for example, arranging colored blocks to match a two-dimensional design) and for tasks measuring verbal knowledge (for example, vocabulary). All tests of anything that you would be likely to call intelligence are correlated at least to some degree. (For that matter, everything that a society holds to be good is correlated with every other good thing to some degree. Life is unfair.)

BOX L.I Children

Subtests Employed on the Wechsler Intelligence Scale for (WISC)

Information:

What continents lie entirely south of the equator?

Vocabulary:

What is the meaning of derogatory?

Comprehension:

Why are streets usually numbered in order?

Similarities:

How arc trees and flowers alike?

Arithmetic:

If six oranges cost two dollars, how much do nine oranges cost?

Picture Completion:

Indicate the missing part from the incomplete picture.

Block Design:

Use blocks to replicate a two-color design.

Object Assembly:

Assemble puzzles depicting common objects.

Picture Arrangement:

Re-arrange a set of scrambled pictures so that they describe a meaningful set of events.

Coding:

Match symbols with shapes using a key as a guide.

As an example of a particular IQ test. Box i. i shows subtests of the Wechsler Intelligence Scale for Children (WISC), which can be given to children aged six to sixteen. Correlations among subtests of IQ tests like this are in the vicinity of .30 to around .60. That they are correlated is reflected in the notion that there is something that corresponds to general intelligence, a construct known as the g factor. (Factor has a technical meaning that is unnecessary for us to pursue. The g factor is itself highly correlated with

Varieties

of Intelligence

7

Figure 1.1. A problem similar to those on the Raven Progressive Matrices test. From Flynn (zoo?). Reprinted with permission.

IQ score, but it is slightly different f r o m IQ score in respects that needn't c o n c e r n us here.) S o m e subtests better c o r r e l a t e with the g f a c t o r than others, a n d we say that they h a v e high g l o a d i n g s . T h e V o c a b u l a r y subtest, for e x a m p l e , is highly correlated with gy whereas C o d i n g (matching s y m b o l s using a key) is not.

The Two

Types of IQ

There are actually t w o components to g or general O n e is fluid

intelligence.

intelligence, or the ability to s o l v e n o v e l , a b s t r a c t

problems—the

type

requiring

mental

operations

that

make

r e l a t i v e l y little u s e o f t h e r e a l - w o r l d i n f o r m a t i o n y o u h a v e b e e n obtaining over y o u r lifetime. Fluid intelligence is exercised via the operation of so-called executive functions. These include " w o r k ing

memory,"

"attentional

control,"

and

"inhibitory control."

T h e information that you must sustain constantly in your mind in order to solve a problem, and that requires some effort to maintain, is said to be held in w o r k i n g m e m o r y . A t t e n t i o n a l c o n t r o l is the ability not only to sustain attention to r e l e v a n t a s p e c t s of the problem but also to shift attention w h e n needed to solve the next step in the p r o b l e m . A n d inhibitory c o n t r o l is the ability to s u p press irrelevant but tempting m o v e s . Figure

i.i

s h o w s a classic e x a m p l e of a

problem

that tests

f l u i d i n t e l l i g e n c e . It's f r o m t h e R a v e n P r o g r e s s i v e M a t r i c e s . T h e

8

I N T E L L I G E N C E A N D H O W T O GET I T

word matrices refers to the collection of figures in the problems— arrayed as 2. x 2. or 3 x 3 matrices. The word progressive refers to the fact that the problems get harder and harder. John C. Raven published the first version of the test in 1938. The example that the problem-solver must follow is set up by the two figures in the top row of the left panel. The figure at the left in the bottom row then specifies what has to be transformed in order to solve the problem. The six figures on the right correspond to the answer alternatives. The solution of the problem requires you to notice that the figure in the upper left of the left panel is a diamond and the figure in the upper right is a square. This tells you that the answer has to be a square. Then you must notice that the bottom half of the upper diamond is divided into two, with the left portion in black. The fact that the left half of the figure on the right is also black tells you that the corresponding portion of the square on the bottom right must match the corresponding portion in the lower left diamond—that is, the entire bottom half must be black. Then you notice that to make the top right figure, one of the bars has been removed from the top left diamond while symmetry of the bars has been preserved. This establishes that you must remove one of the bars of the square at the bottom while preserving symmetry. N o w you know that the correct answer must be the square at the bottom right of the answer panel. Of the subtests on the W I S C shown in Box 1.1, the ones that most involve fluid intelligence are Picture Completion, which requires you to attend to all aspects of a figure and analyze which portion of it is missing; Block Design, which requires you to operate with purely abstract visual materials; Object Assembly, which requires going back and forth between your knowledge of what the desired object looks like and the abstract shapes that must be used to compose it; Picture Arrangement, which requires you to hold in working memory the various pictures and to rearrange them mentally until a coherent story is told by the pictures in a given order; and Coding, which is a completely abstract task that measures primarily speed of information processing. Scores on

Varieties

of Intelligence

9

these types of tests are sometimes said to comprise the Performance IQ, referring to the fact that all of the subtests require performing operations of some kind. These operations are brought to bear on the spot and draw only somewhat on stored knowledge. The other type of general intelligence is called crystallized intelligence. This is the store of information that you have about the nature of the world and the learned procedures that help you to make inferences about it. The subtests on the W I S C that tap crystallized intelligence most heavily are Information, Vocabulary, Comprehension, Similarities, and Arithmetic. Doing arithmetic, of course, involves both calling up stored or crystallized knowledge and performing operations, most if not all of which have been learned previously. The W I S C creators refer to the total of the scores on this collection of subtests as Verbal IQ, since most of the information being drawn upon is verbal in nature. The score that combines Performance IQ with Verbal IQ is called Full Scale IQ. H o w do we know that there are two fundamentally different types of general intelligence? We know this first because the subtests that we describe as performance-oriented clearly draw relatively more on reasoning skills (fluid intelligence) than on knowledge (crystallized intelligence), and the subtests that we call verbal clearly depend relatively more on knowledge (including knowledge about algorithmic solutions) than on reasoning skills. Also, the verbal subtests have higher correlations with one another than they do with the performance subtests, and vice versa. In addition, the subtests that we call measures of fluid intelligence rest on executive functions that are mediated by a portion of the frontal cortex called the prefrontal cortex (PFC) and another region linked in a network with the PFC called the anterior cingulate. The destruction of the PFC has devastating consequences for mental tasks that require the executive functions of working memory, attentional control, and inhibitory control. People with severe damage to the PFC may be so incapable of solving Raven matrices that they function at the level of mentally retarded people on that test, yet have crystallized intelligence that is entirely nor-

10

I N T E L L I G E N C E A N D H O W T O GET I T

mal. The opposite pattern also occurs. Autistic children usually have impaired crystallized intelligence but may have normal or even superior fluid intelligence. As one would expect given the lesion evidence, the PFC is particularly active, as demonstrated in brain-imaging studies, when people attempt to solve problems that make substantial use of fluid intelligence, such as the Raven matrices and difficult mathematical problems. Additional evidence for the two types of intelligence is that fluid intelligence and crystallized intelligence have quite different trajectories over a lifetime. Figure 1.2. shows an idealized version of those trajectories. The growth of fluid intelligence is rapid over the first years of life but begins to decline quite early. Already by the early twenties, fluid intelligence shows some decline. Mathematicians and others who work with symbolic, abstract materials for which they must invent novel solutions may find their powers fading somewhat by the age of thirty. By seventy years old, fluid intelligence is noticeably less than it has been—more than one standard deviation lower.

Years of age

Figure 1.2. Schematic rendering of fluid intelligence and crystallized intelligence over the life span. From Cattell (1987).

Varieties of Intelligence 22

Older people find it harder to solve puzzles and mazes. Crystallized intelligence, on the other hand, may continue to increase over the lifespan, at least until very old age. Historians and others whose best work depends on a large storehouse of information may find their powers increasing well into their fifties. N o t e that everything 1 have just written about the age trajectories of fluid and crystallized intelligence is controversial to some degree. I will spare you the ins and outs of this controversy and simply say that the universally agreed-upon fact is that fluid intelligence begins to decline earlier than crystallized intelligence. That fluid intelligence declines earlier in life than crystallized intelligence could be predicted by the fact that the PFC shows deterioration earlier than other structures in the brain. A final source of evidence that the two types of intelligence exist is that executive functions and overall IQ may be separately heritable. Executive functions are inherited to a degree from parents, and so is crystallized intelligence, or the knowledge that helps people solve problems. A person can inherit relatively high executive function from parents who have relatively high executive function, yet can inherit relatively low crystallized intelligence from the same parents who score relatively low on this dimension. Fluid intelligence is more important to good intellectual functioning for younger people than it is for older people. For young children, the correlation between fluid intelligence and reading and math skills is higher than that for crystallized intelligence. In contrast, for older children and adults, the correlation between crystallized intelligence and reading and math skills is higher than that for fluid intelligence. This point becomes crucial later, when I discuss some of the reasons for the relatively low IQ of people of lower socioeconomic status and members of some minority groups, and some of the possible ways to improve IQ. Another extremely important fact about fluid intelligence is that the PFC has substantial interconnections with the limbic lobe, which is heavily involved in emotion and stress. During emotional arousal, there is less activity in the PFC, and so fluid-intelligence

12

I N T E L L I G E N C E A N D H O W T O GET I T

functioning is worse. Over time, continued stress may result in permanently reduced PFC function. This information too becomes critical later, when I discuss the modifiability of fluid-intelligence functioning for the poor and minorities. In the meantime, however, I focus on the simple IQ score, combining fluid and crystallized intelligence, and make distinctions between the two types of intelligence when that is important.

Varieties

of Intelligence

What do IQ scores predict? First of all, they predict academic grades. This is scarcely surprising, because that is why Alfred Binet invented IQ tests more than a hundred years ago. He wanted to be able to determine which children would be unlikely to benefit from normal education and therefore would require special treatment. The correlation today between the scores on typical intelligence tests and the grades of schoolchildren is about .50. That value is substantial, but it leaves room for a great many variables that are not measured by an IQ test to play a role in predicting academic performance. IQ tests tend to measure what has been called "analytic" intelligence as distinct from "practical" intelligence. Analytic problems typically have been constructed by other people; are clearly defined; have all the information necessary to solve them embedded in their description; have only one right answer; usually can be reached only by one particular strategy; are often not closely related to everyday experience; and are not particularly interesting in their own right. These can be contrasted with "practical" problems, which require recognition that there is something to be solved; are usually not well defined; typically require seeking out information relevant to their solution; have several different possible solutions; are often embedded in everyday experience and require such experience for their solution; and engage—and usually require—intrinsic motivation. Robert Sternberg measures practical intelligence with questions

Varieties

of

Intelligence

13

asking people, for example, how to handle problems like entering a party where one does not know anyone, discussing what share of rental payments is fair for each of several people, and writing a letter of recommendation for someone who is not well known to the person writing it. Sternberg also writes about a third type of intelligence, which he calls "creative" intelligence. This is the ability to create, invent, or imagine something. He measures creative intelligence by, for example, giving people a title, such as " T h e Octopus's Sneakers" or "A Fifth Chance," and asking them to write the story. He also measures creative intelligence by asking people to look at a sequence of pictures and having them tell a story about one of them, and by having people develop advertisements for new products. When Sternberg measures analytic intelligence in the standard way, by S A T or A C T scores or IQ tests, and practical and creative intelligence by his novel measures, he finds that his practical and creative measures add to the predictability of outcomes such as success in school and work performance. Sometimes the increments in predictability are substantial; in fact they sometimes outperform IQ tests by a significant margin. Sternberg is highly persuasive when he talks about three hypothetical graduate students. Analytic Alice is brilliant in discussion of ideas and is a superb critic of the products of others. Creative Cathy is not so incandescent in her treatment of ideas, but she comes up with lots of interesting notions of her own, a certain fraction of which end up paying off. Practical Patty is neither analytically brilliant nor especially innovative. But she can figure out a way to get the job done. She can get from here to there in sensible, cost-effective ways. What you hope for are colleagues with all three types of intelligence, of course, but especially when you work on a team, even the people who stand out in only one dimension have a vital role to play. It is worth noting that Sternberg's measures of practical and creative intelligence show much less of a separation between minority and majority groups than do analytic tests, meaning that

14

I N T E L L I G E N C E A N D H O W T O GET I T

they become a way to bring more minorities into educational and occupational roles where their entrance might be blocked by tests of analytic intelligence. H o w a r d Gardner argued that IQ tests measure only linguistic, logical-mathematical, and spatial abilities but neglect other "intelligences." These include various "personal intelligences" resembling the "emotional intelligence" that social psychologist Peter Salovey and his colleagues researched. Emotional intelligence includes being able to accurately perceive emotion, using emotions to facilitate thinking, understanding emotions, and managing emotions in self and others. Emotional intelligence as measured by Salovey and his colleagues is virtually uncorrelated with analytic intelligence as measured by IQ tests, but it predicts peer and supervisor ratings of dimensions like interpersonal sensitivity, sociability, contributing to a positive work environment, stress tolerance, and leadership potential. Some might want to avoid the term intelligence for these measures of emotional skills, but that is a quibble. The other intelligences that Gardner discussed are "musical" and "bodily kinesthetic." Some intelligence researchers are utterly contemptuous of using the term intelligence for these skills. But there are such things as musical and kinesthetic ideas, and there are such things as musical and kinesthetic problems to be solved. I'm personally willing to call Beethoven's Seventh Symphony and Alvin Ailey's "Revelations" works of genius. So I am perfectly content to say that the skills that invented those works are the products of intelligence. But I wouldn't try to press my personal preference on others w h o arc resistant to that label. Gardner justified his lengthening of the list of intelligences by pointing out that there are child prodigies for most of them, and there is neurological evidence that different areas of the brain are specialized for each of the intelligences he identified. Whether one calls his additions to the intelligence list mere skills or something else, it is clear that they are somewhat separate from the standard analytic ones and that measures of them predict—or in principle

Varieties

of Intelligence

15

could predict—important aspects of skilled human endeavor that the standard tests do not.

Motivation

and

Achievement

Finally, characteristics that no one would call intelligence have a marked effect on academic and occupational achievement. Decades ago, personality psychologist Walter Mischel studied the ability of children to delay gratification. He put preschoolers from a Stanford University nursery school into a room (alone, they thought, but with an experimenter watching their every move) where there was a cookie, a marshmallow, a toy, or some other desirable object. The children were told that they could have the object whenever they wanted. They had only to ring a bell and then the experimenter would come in and let them have the object. Or they could wait until the experimenter returned of his own accord. If they waited that long they could have two cookies, marshmallows, or toys. The dependent measure is called the "delay of gratification." The longer the child waits before ringing the bell, the greater the ability to delay gratification. Mischel then waited more than a decade, until these mostly upper-middle-class kids were in high school. The children who had waited the longest before taking the goodie were rated by their parents as being better able to concentrate, better planners, and better able to tolerate frustration and to deal maturely with stress. These traits paid off in tests of measured academic intelligence. The greater the toddler's ability to delay gratification, the higher the S A T score in high school. The correlation between delay time of the toddler and the S A T Verbal score was .42.; the correlation for the S A T Math score was .57. It is possible that the brighter toddlers are the ones who had the longer delay times, but it seems unlikely that this is the whole explanation. M o r e plausible is that children who were better able to resist temptation were better able to hit the books when they got older. This is not the last time we will have occasion to note that S A T scores, which correlate highly

16

I N T E L L I G E N C E A N D H O W T O GET I T

with IQ scores, are not equivalent to I Q . Some cultural groups do better on S A T scores than would be predicted by their I Q — f o r reasons that probably have to do with motivation. That motivational factors affect academic achievement levels is scarcely shocking. That motivation may sometimes actually be a better predictor of academic achievement than IQ is, however, a surprise. This is what an extremely important study found for eighth-graders at a magnet school in a large city in the Northeast. Psychologists Angela Duckworth and Martin Seligman measured self-discipline in a variety of ways. They asked the students about the degree to which they said and did things impulsively; they quizzed the students about different kinds of rewards, asking them about the degree to which they would prefer a small, immediate version of the reward versus a large, delayed reward; they actually offered the children one dollar immediately versus the opportunity to get two dollars a week later; and they asked parents and teachers about each student's ability to inhibit behavior, follow rules, and control impulsive reactions. They combined scores on all of these measures into a single omnibus measure of self-discipline and then compared how well this measure predicted grades versus how well a standard IQ test predicted grades. The result: the IQ test was not nearly as good a predictor of grades as the motivational measure. The correlation for IQ was a very modest .32.. The correlation for self-discipline was more than twice as high—.67. The self-discipline measure was a slightly better predictor of standard school achievement test scores than was IQ—.43 versus .36, though the difference was not statistically significant. If you had to choose for your child a high IQ or strong self-discipline, you might be wise to pick the latter. The results of the Duckworth and Seligman study, important as they are, need to be replicated. The differences between self-discipline and IQ as predictors of achievement might not be the same at a nonselective school or even another magnet school. Nevertheless, the study stands as proof of the hypothesis that motivational factors can count more than IQ as a predictor of achievement.

Varieties

of

Intelligence

17

Let's draw together some of the lessons of the research 1 have been describing. IQ is only one component of intelligence. Practical intelligence and creative intelligence are not well assessed by IQ tests, and these types of intelligence add to the predictability of both academic achievement and occupational success. Once we have refined measures of these types of intelligence, we may find that they are as important as the analytic type of intelligence measured by IQ tests. Intelligence of whatever kind and however measured is only one predictor of academic and occupational success. Emotional skills and self-discipline and quite possibly other factors involving motivation and character are important for both. To these qualifications of the importance of IQ, we can add the fact that, above a certain level of intelligence, most employers do not seem to be after still more of it. Instead, they claim that they're after strong work ethic, reliability, self-discipline, perseverance, responsibility, communication skills, teamwork ability, and adaptability to change. So IQ is not the be-all and end-all of intelligence, and intelligence, even when defined more broadly than IQ score, is not the only important factor influencing academic success or occupational attainment. And academic success is itself only one predictor of occupational success.

What IQ

Predicts

Nevertheless, IQ and academic success are associated with a great many outcomes. But it is surprisingly difficult to specify exactly what the causal pathways are. Researchers often determine the individual's contemporary IQ or IQ earlier in life, socioeconomic status of the family of origin, living circumstances when the individual was a child, number of siblings, whether the family had a library card, the educational attainment of the individual, and other variables, and put all of them into a multiple-regression

18

INTELLIGENCE A N D H O W T O GET I T

equation predicting adult socioeconomic status or income or social pathology or whatever. Researchers then report the magnitude of the contribution of each of the variables in the regression equation, net of all the others (that is, holding constant all the others). It always turns out that IQ, net of all the other variables, is important to outcomes. But as I make clear in Appendix A on statistics, the independent variables pose a tangle of causality—with some causing others in goodness-knows-what ways and some being caused by unknown variables that have not even been measured. Higher socioeconomic status of parents is related to educational attainment of the child, but higher-socioeconomic-status parents have higher IQs, and this affects both the genes that the child has and the emphasis that the parents are likely to place on education and the quality of the parenting with respect to encouragement of intellectual skills and so on. So statements such as " I Q accounts for X percent of the variation in occupational attainment" are built on the shakiest of statistical foundations. What nature hath joined together, multiple regression cannot put asunder. But it is possible to get a much firmer bead on the importance of IQ in determining life outcomes. Political scientist Charles Murray has looked at people whose IQs were measured by the Armed Forces Qualification Test as part of the National Longitudinal Survey of Youth begun in the late 1 9 7 0 S . He examined income and other social indicators for the original group when they were adults many years later. But he did this for a highly selected sample—sibling pairs who were not born into poverty (that is, their income was higher than the lowest quartile of income), who were not illegitimate, and whose parents were together at least up until the child was seven. But the pairs had to differ in IQ. Each person either had an IQ in the normal range— from 90 to 1 0 9 — o r had one outside that range. The sibling with an IQ outside that range could either be bright (110—119), very bright ( 1 2 . 0 + ) , dull ( 8 0 — 8 9 ) , o r very dull (less than 8 0 ) . Murray could ask for this sample, which he called "utopian," how much difference it made to have IQ in the normal range versus

Varieties

of Intelligence

19

outside that range in one direction or another. The firmest measure that he had was the income of the individuals as adults. Income, of course, is correlated with occupational attainment and social class, so when we look at income we can treat it as a proxy for these other variables as well. He also had good data on whether the women in the sample had given birth to illegitimate children. This variable too can be taken as a proxy for a large number of other variables, in this case some involving social dysfunction such as likelihood of incarceration and likelihood of being on welfare. What Murray found is that even in this stable, mostly middleclass group of siblings, different IQs are associated with very different outcomes. Table I . I shows that if a person had a normal-IQ sibling but was very bright himself or herself, the very bright sibling made more than a third more money (and thus would have had on average a substantially higher-status job). If a person had a normal-IQ sibling but was himself or herself very dull, the very dull sibling made less than half as much as the normal-IQ sibling. Illegitimate births were also very much tied to IQ. Very dull women were two and a half times as likely to have illegitimate children as their normal-IQ siblings.

TABLE I . I Relationship between IQ and income and percentage of women having illegitimate children, for siblings from the same stable, middle-class family who differ in IQ IQ

Croup

Income

Illegitimacy

Rate

10

Reference group ( 9 0 - 1 0 9 )

$70,700 $60,500 $5.1,700

Dull siblings ( 8 0 - 8 9 )

$39,400

33

Very dull siblings (< 80)

$2.3,600

44

Very bright siblings (12.0+) Bright siblings (i 10-1 19)

(%)

2. 17

What is important about these analyses is that they show that members of the same family who have different IQs have very different life outcomes on average. Importantly, the analyses remove

20

I N T E L L I G E N C E A N D H O W T O GET I T

from consideration the effects of socioeconomic status of the family of origin, since all of the comparisons are between members of the same family. The analyses do not prove that IQ alone is directly causing those outcomes. For example, it is likely that educational opportunity, which is mediated by IQ, is also an important part of the causal chain. In effect, education probably acts as a multiplier of the effect of I Q . And IQ is undoubtedly associated with aspects of character and motivation that play a role as well. But the results are very telling about the importance of IQ and its correlates even among members of the same, relatively high-status and stable, family. The IQ scores Murray examined arc undoubtedly influenced substantially by genes. Some children in a family get a better luck of the genetic draw from their parents. Murray himself has long been associated with the view that IQ is largely genetically determined, and with the view that, partly because of this, IQ is not very susceptible to influence by environmental factors. But how important are genes, exactly? And what role do they leave for the environment? In the next chapter I pursue the questions regarding the degree to which intelligence is something that is inherited and the degree to which the environment can modify it.

CHAPTER TWO

Heritability a n d M u t a b i l i t y • • • 75 percent of the variance [in IQ] can be said to be due to genetic variables . . . and z$ percent to environmental variation.

— A r t h u r Jensen (i 9 6 9 )

Being raised in one family, rather than another . . . makes fetv differences in children's personality and intellectual development.

— S a n d r a Scarr (1992.)

so V E R Y L O N G A G O , scientists w h o study I Q more or less agreed that intelligence is mostly heritable. Some still consider it to be about 75 to 85 percent heritable, at least for adults.The effects of the environment that children share by virtue of being raised in the same family have often been presumed to be slight, sometimes literally zero by the time the children are adults. Scientists frequently believed, or at least wrote as if they did, that the overwhelming importance of heritability meant that the environment could do little and that social programs intended to improve intelligence were doomed to failure. NOT

But many scientists today consider the heritability of IQ to be much lower than 75 to 85 percent. This environmentalist camp estimates heritability to be .50 or less. (Though, as you will see later, heritability actually differs quite a bit from one population group to another.) And I agree with these scientists—in fact I suspect heritability may be even lower than .50. In the first section of this chapter, I show why earlier estimates of heritability were so high. Even more important, I review the results of adoption studies showing that raising someone in an upper-middle-class environment versus a lower-class environment 21

22

INTELLIGENCE A N D H O W T O GET I T

is worth i 2. to 18 points of I Q — a truly massive effect. This fact places a very high upper bound on the degree to which the environment can influence intelligence. Finally, 1 emphasize that the heritability of a characteristic places no theoretical limits on the degree to which it can be affected by the environment. The upshot is that the environment counts for a lot in determining IQ and could conceivably account for more if we could think of the right ways to change it. Some of the notes for this chapter are long. This is because I want to answer the concerns of specialists in the heritability of IQ without derailing the attention and understanding of the general reader. Even without the notes, this chapter is by far the most technical in the book. Please don't get bogged down in it. Rather, take on faith for the time being my assertions that genes are far from being completely determinative of intelligence and that the environment can made a huge difference to intelligence.

Heritability,

Environment

and

IQ

Laypeople sometimes think of the heritability of a characteristic as the degree to which it is inherited from parents. This encourages the assumption that a heritability estimate for IQ of .80 means that 80 percent of a person's IQ comes from genes. This is quite wrong. Heritability does not refer to the individual at all, but to populations. The heritability of a characteristic refers to the percentage of variation in that characteristic in a particular population that is due to genetic factors. This contrasts with the percentage of variation in the characteristic due to all other factors. For intelligence, these other factors include prenatal and perinatal biological factors, environmental factors of a biological nature such as nutrition, and social factors such as education and experience. This chapter concerns the most interesting sources of variation—that due to genetics and that due to the environment which is shared among children in a given family but differs between families.

Heritability

and

Mutability

23

The between-family environmental effect refers to how much difference it makes that a person was raised in one family versus another (with all the various factors that go with membership in different families, such as social class, rearing styles, and religious orientation). The between-family environmental source of variation does not include environmental variation within a family, such as that associated with birth order. Only one child in a family can be the first born, only one can be the second born, and so on. And we know that birth order can be an important factor associated with some characteristics. Other factors such as peer influences and schools attended also differ among children within a given family. Of course, between-family environmental differences do not include the genetic contribution of the parents. Everyone agrees that there are big average differences in IQ between t w o randomly selected families, and a substantial portion of those differences is due to genes. The researchers I call the strong hereditarians hold that IQ is between 75 and 85 percent heritable in the population of developed countries, and that the environmental contribution from all sources is between 15 and 2.5 percent. M o s t of the strong hereditarians believe that the between-family environmental contribution (growing up with the Smiths rather than the Joneses) is slight to nil, at least after childhood. They also agree that such environmental contribution as exists is mostly due to variations that occur within the f a m i l y — f o r example, the children having gone to different schools, having been treated differently by their parents, and having experienced a different uterine environment. H o w do the strong hereditarians reach these conclusions? Have a look at Table 2..1, which summarizes the results of a large number of studies of the correlations between individuals with a given degree of relatedness w h o were raised either together or apart. A direct estimate of heritability is provided by the figure for identical twins—who have the same genetic m a k e u p — w h o

24

I N T E L L I G E N C E A N D H O W T O GET I T

are reared apart. This figure is .74, and is essentially the one that Arthur Jensen drew upon to derive his estimate of the contribution of genes to I Q . Since the environments of the twins are different, so the logic goes, the similarity between the twins can only be due to genetics (as well as to prenatal and perinatal effects that might have been consequential before the twins were separated and which are generally assumed by the hereditarians to be minimal). TABLE 2.1 Correlations for individuals with ship, raised either together or apart Relationship

Raised

varying degrees of relation-

Correlation

Identical twins

Together

.85

Identical twins

Apart

•74

Fraternal twins

Together

•59

Siblings

Together

Siblings

Apart

.46 .24 .50

Midparent/child

Together

Single parent/child

Together

•41

Single parent/child

Apart

.24 .20 .26

Adopting parent/child

Together

Adopted children

Together

M i d p a r e n t = average o f m o t h e r ' s a n d f a t h e r ' s I Q . C o r r e l a t i o n s are based on a s u m m a r y of 2.12. d i f f e r e n t studies a n d are w e i g h t e d by the size o f t h e sample. F r o m D e v l i n , D a n i e l s , a n d Roeder ( 1 9 9 7 ) , except f o r the c o r r e l a t i o n f o r a d o p t e d c h i l d r e n raised t o g e t h e r , w h i c h i s f r o m B o u c h a r d a n d M c G u e (2.003).

H o w do scientists typically arrive at a direct estimate of the role of between-family environmental differences? They examine the correlation between the IQs of unrelated individuals living together. A direct way to estimate this is by determining the correlation between the IQs of adopted children and those of their adoptive parents. Since these people do not share genes, the only way that the IQs of the adopted children can resemble those of their adoptive parents is by virtue of sharing the same environment. The next-to-last line of Table 2..1 shows that this correla-

Heritability

and

Mutability

25

tion is .20. Some scientists take this as a good estimate of the contribution of the environment to the variation in IQ from one family to another. A different way of arriving at this conclusion is to compare the IQs of unrelated children living in the same family (the last line in Table 2..1). Again, because the children do not share genes, the only way they can resemble one another is through sharing the same environment. This correlation is .2.6, a slightly higher estimate of the contribution of between-family differences to IQ. Jensen and other strong hereditarians, however, would not accept a figure for between-family environmental effects that is as high as .2.0 to .2.6. This is because when people older than those in the studies summarized in Table 2..1, who are mostly children, are examined, the correlations drop dramatically—sometimes to as low as zero. This is true, for example, for unrelated children brought up in the same household. When they are adults, the correlations run in the vicinity of .05 or less. The usual explanation given for this weak effect on adults is that as people grow older, they select their own environments, and their preference for one environment versus another is largely influenced by genetics. The importance of the early environment, never all that great to begin with, drops way off. This means that the strong hereditarians assign most of the environmental contribution to IQ to factors that differ among members of the same family, such as birth order, rather than to factors that are common to the members of the same family and that differ between families. To summarize, the strong-hereditarian position is as follows: three-quarters or more of the variation in IQ is genetic; some of the variation in IQ is due to nonshared, within-family environmental factors that a parent cannot do much about; and by adulthood almost nothing of the variation in IQ is due to between-family environmental differences—the difference between randomly chosen family A and randomly chosen family B. So the characteristics of your family, in comparison to the characteristics of the randomly selected Joneses—who might make less money, not

26

INTELLIGENCE A N D H O W T O GET I T

read as much to their kids, send them to poorer schools, live in a sketchier neighborhood, and have a different religion—make almost no difference. By now, if you have children, you could be wondering why you spent good money to move to a more expensive neighborhood with better schools, or for that matter why you squander money on books and orthodontia, waste time driving them to violin lessons and museums, and drain off emotional energy holding your temper so as to set a good example. But you don't have to accept those high estimates of heritability and low estimates of betweenfamily environmental effects. The direct estimate of heritability based on the correlation between the IQs of identical twins reared apart makes a tacit assumption that is surely false—namely, that the twins were placed into environments at random. For that to be true, the twins would have to be in environments that differed as much as any t w o people selected at random from the Google-based U.S. telephone book. But that is not the case. Billy is likely to be raised by people—frequently relatives in fact—not all that different from those raising Bobby. And just how similar the environments are makes a good deal of difference for the correlations in IQ between identical twins reared apart. Developmental psychologist Urie Bronfenbrenner showed that when twins reared apart are brought up in highly similar environments, the correlations between their IQ scores range from .83 to .91. But the correlation now reflects not just the fact that their genes are identical but also the fact that their environments are highly similar. Such a correlation therefore gives an inflated estimate of heritability. When environments are dissimilar to one degree or another, the correlations range from .2.6 to .67. Since we don't know just how dissimilar the environments are in most studies of twins reared apart, we can't know exactly what heritability to estimate from the correlation between them. Regardless of the degree of similarity in environments, the correlation between identical twins overestimates heritability as

Heritability

and

Mutability

27

c o m p a r e d to other ways of estimating heritability based on the correlations for other kinds of relatives. This could be because the environmental experiences of identical twins w h o are reared separately in quite different environments are highly similar since they look so much alike or have other characteristics in common that tend to elicit the same sorts of behavior from other people. Or there may be gene interactions that specifically make identical twins more similar but that don't contribute much to the degree of resemblance of other relatives.

A third source of error in the .75 to .85 estimates is that twins share the same uterine environment. Devlin and his colleagues maintain that this shared-environment factor means that as much as 20 percent should be subtracted from the heritability estimates. I will present a fourth source of error later, when I discuss the fact that heritability differs greatly from one social class to another—and that twin studies are biased toward including disproportionately large numbers of people from social classes for which heritability is high. Once corrections are made for all these facts, the estimate based on identical twin correlations is likely to be substantially lower than the .75 to .85 assumed by Jensen and the other strong hereditarians.

Genes as

Triggers

of Environmental

Influences

Developmental psychologists Sandra Scarr and Kathleen McCartney, as well as economist William Dickens and philosopher and IQ scientist James Flynn, propose a further reason why the role of genes is overestimated. Slight genetic advantages can be parlayed into very great IQ advantages because of the way they influence the kinds of experiences an individual has. Consider a basketball analogy. The child who is somewhat taller than average is more likely to play basketball, more likely to enjoy the game, more likely to play a lot, more likely to get noticed by coaches and encouraged to play for a team, and so on. That height advantage is totally depen-

28

I N T E L L I G E N C E A N D H O W T O GET I T

dent on such environmental events for its expression. And identical twins reared apart are likely to have very similar basketball experiences, because they are of similar height, so they are likely to end up with similar skills in basketball. But their similarity in basketball skills is not due to their possessing identical "basketball-playing genes." Instead, it is due to genetic identity in a narrower attribute that causes them to have highly similar basketball-related experiences. A similar point can be made about intelligence. A child with a relatively small genetic advantage in, say, curiosity is more likely to be encouraged by parents and teachers to pursue intellectual goals, more likely to find intellectual activity rewarding, and more likely to study and engage in other mental exercises. This will make the child smarter than a child with less of a genetic advantage—but the genetic advantage can be very slight and can produce its effects by virtue of triggering environmental "multipliers," which are crucial for realizing that advantage. All of this gene-environment interaction (or as geneticists would prefer to say, gene-environment correlation), however, gets credited to heritability, given the way heritability is calculated. This is not wrong, but it leads to an underestimation of the role of the environment. To make it even clearer why heritability estimates slight the role of the environment, let's return to the basketball analogy. Suppose a child of average height is encouraged to play basketball, perhaps because her older siblings are players and keep a well-used hoop on the driveway. And suppose another child, of above-average height, has little access to basketball experiences, perhaps because she lives in a rural area and there are no neighborhood kids nearby. The taller child from the rural area is not likely to become much of a basketball player, whereas the average-height child has a reasonable chance of becoming good. N o w we have a child with a genetic advantage who is not very good at basketball, and a child with a genetic disadvantage who nevertheless is pretty good at it. Genes count, and given a constant environment they may have a big influence in determining talent. But environmental interventions can greatly influence—even largely override—the effects of genes. This is particularly important

Heritability

and

Mutability

29

for estimates of the effects of the environment on IQ. It is easy to imagine any number of ways in which intellectual pursuits can be made more or less available and attractive.

Tolstoy

and

Adoption

N o w let's consider how the effects of between-family environmental differences are measured. These differences are estimated by calculating the correlation between the IQs of adopted children and those of their adoptive parents, and the correlation between children in the same family who are not related to each other (usually adopted children). As we have seen, the correlations turn out to be low on average—around .20 to .2.5. But these numbers only make sense if we assume that the variation in the environments created by adoptive parents is about the same as the variation in the population as a whole. It turns out, though, that adoptive families, like Tolstoy's happy families, are all alike. Psychologist Mike Stoolmiller showed that the variation in factors that predict IQ is, for adoptive families, a fraction of what it is for families in general. We know this for t w o reasons. First, the socioeconomic status (SES) of adoptive families is higher than that of nonadoptive families; the bottom rung of the SES ladder is scarcely represented among adoptive families. Second, there is much less variation in scores derived from a method of assessing home environments called the H O M E ( H o m e Observation for Measurement of the Environment). H O M E researchers assess family environments for the amount of intellectual stimulation present, as indicated by how much the parent talks to the child, how much access there is to books and computers, degree of warmth versus punitiveness of parents' behavior, and so on. H O M E assessments show that adoptive families rate far above the general run of families in these respects. In fact, adoptive families score at the 70th percentile on average. Just as important, the range on these variables is very restricted compared to the population at large. H O M E measures for disadvantaged families

30

INTELLIGENCE A N D H O W T O GET I T

are five times as variable as those for adoptive families; that is to say, disadvantaged families differ far more from one another on average than do adoptive families. Why does restricted range of environmental variation result in correlation estimates that are too low? Because if there is very little variation in one variable being correlated with another, the correlation cannot be very high. Consider the extreme case of variable A, which has no variation: the correlation with variable B is zero. High and low scores on B would alike be associated with the same score on variable A, so the correlation between scores on variables A and B can only be zero. Therefore, if the variation in environments between adoptive families is mistakenly estimated as being higher than it really is, the impact of the environment on IQ will be underestimated. Because the environmental variation of adoptive families has mistakenly been assumed to be as great as the environmental variation in the population as a whole, the estimates of betweenfamily environment effects are way off. Stoolmiller calculated that if you correct for this restriction of environmental range, as much as 50 percent of the variation in intelligence could be due to differences between family environments. Since we know that within-family variation also makes an important contribution to IQ, this would mean that most of the variation in IQ is due to the environment. (These numbers would hold, though, only for children. We know that heritability goes up with age to some degree, so Stoolmiller's estimate for the contribution of between-family differences has to be lowered by some unknown amount.)

There Is No Such Thing as the Heritability of IQ (or Anything Else, for That Matter) So what value should be assigned to heredity's contribution to IQ? Actually, geneticists say that there is no such thing as a single point estimate for heritability. Heritability is dependent on the particular population and the particular circumstances in which

Heritability

and

Mutability

31

it is examined. For IQ in particular, the nature of the population turns out to be crucial. Psychologist Eric Turkheimer and his colleagues recently showed that heritability is radically dependent on social class. They found that the heritability of IQ was about .70 for children whose parents were upper-middle class but was about .10 for children whose parents were of lower social class. A plausible explanation for this is that higher-SES families are providing excellent conditions for the development of intelligence, and they may not differ much among themslves in these respects. Under these circumstances, the contribution of heredity can be very great. At the extreme, if the environment is completely constant across families, the only possible source of variation is genetic. Why should the heritability of IQ be so low for lower-SES people? We know from the work by Stoolmiller that the range of environments with respect to the variables that influence IQ is far greater for lower-class families than for middle- and uppermiddle-class families. The environment for lower-SES people probably varies from being equal to the most supportive uppermiddle-class setting to being pathological in every respect. This means that the environment for this group of people is going to make a great deal of difference to IQ. And in fact the environment almost completely swamps heredity. So you haven't wasted your time, money, and patience on your children after all. If you were to average the contribution of genetics to IQ over different social classes, you would probably find 50 percent to be the maximum contribution of genetics. Most of the remainder of variation in IQ is due to environmental factors— those shared within families and differing between families, plus those not shared within families. (The rest—a small amount—is due to measurement error.) N o t e also that the Turkheimer findings provide yet another, and crucially important, indication that the very high estimates of heritability are overestimates. This is because they are based largely on twin studies, and there is a substantial bias in twin studies toward middle-class participants since middle-class and

32

I N T E L L I G E N C E A N D H O W T O GET I T

upper-middle-class people are easy to contact and to persuade to participate in research projects. Therefore, estimates of heritability for adults are biased upward, and estimates of between-family environmental effects correspondingly biased downward. Stoolmiller's claims about the superiority of adoptive parents from the standpoint of encouraging the development of intelligence raise the question of just how big the effects of adoption are. Addressing this issue would provide another way of drawing a bead on the contribution of family environment to IQ. If adoptive families are such an exemplary bunch with respect to the variables that predict IQ, shouldn't we find adopted children to have IQs that are higher than would be expected from their origins? We certainly would under the hypothesis that environments matter a great deal to IQ.

The Proof of the Importance Environment in Determining

of Family IQ

Heritability estimates are based on correlations, and as we have just seen, inferences based on correlations can be misleading. What is needed to test the power of differences between family environments are experiments. As it turns out, there are a large number of natural experiments based on the everyday occurrence of adoption. We can ask if it makes a difference whether children are adopted into a family with highly favorable environmental conditions versLis a family with less favorable conditions. Many natural experiments, with many different "designs," point to the same conclusion: being raised under conditions highly favorable to intelligence has a huge effect on IQ. Psychologists Christiane Capron and Michel Duyme carried out a "cross-fostering" study with French children. They tracked down children born to low- or high-SES parents who had been adopted by either low- or high-SES parents. The class differences were pronounced: they compared children of poor and workingclass parents based on occupation of the father (semi-skilled or

Heritability

and

Mutability

33

unskilled worker having nine years of education or less) with children of upper-middle-class parents (professional or upper-level manager, having an average of sixteen years of education). This design allowed an independent assessment of the contribution to IQ of genes from parents of very low versus very high SES and the contribution to IQ of being raised in a very-low- versus very-highSES family. As it turns out, both genes and class-related environmental effects are powerful contributors to intelligence. On average, the biological children of high-SES parents had IQs that were 12 points higher than those of low-SES parents, regardless of whether they were raised by high-SES parents or low-SES parents. ( W e don't know how much of this difference was due to genes and how much was due to nongenetic prenatal, perinatal, and immediate postnatal environmental factors, though I don't doubt that most of the difference was genetic.) The crucial finding is that children adopted by high-SES parents had IQs that averaged 12 points higher than the IQs of those adopted by low-SES parents—and this was true whether the biological mothers of the children were of low or high SES. So the study showed that being raised in higher-social-class environments produces children with a far higher IQ than does being raised in lower-social-class environments. Equally important, the school achievement of children raised in upper-middle-class environments was much higher than that of children raised in lowerclass environments. Another French study, having a different "natural experiment design," examined lower-SES children adopted into upper-middleclass families and compared them with their siblings w h o had not been adopted. The adopted children had an average IQ of 107 by one test and 1 1 1 by another, whereas their biological siblings who were not adopted had an average IQ of about 95 by both tests. We therefore get an estimate of 12 to 16 IQ points as the value of being raised in an upper-middle-class environment versus a lower-class environment. The difference in academic achievement between adopted and nonadopted siblings was huge. The school

34

I N T E L L I G E N C E A N D H O W T O GET I T

failure rate was 13 percent for children adopted by upper-middleclass parents and 56 percent for their nonadopted siblings. In another extremely important natural experiment conducted in France, but with yet a different design, Duyme and his colleagues looked at abused, low-IQ children who were tested for IQ adopted at the age of four or five and then retested for IQ at age fourteen. They deliberately searched for children who had been adopted into families of varying social classes. When younger, the children had IQs between 61 and 85—between what IQ testers describe as decidedly retarded and dull-normal levels. The families into which they were adopted were poor (unskilled workers), lower middle and middle class (lower- or middle-level managers, tradesmen, and skilled laborers), or upper middle class (professionals and high-level managers). The effects on IQ of being adopted were very large, 14 points on average. But the social class of the family made a great difference. Children adopted into lower-SES families gained 8 points; those adopted into middle-class families, t6 points; and those adopted into upper-middle-class families, almost 2.0 points. This gives an estimate of iz points for the effect of being raised by an upper-middle-class family as opposed to a lower-class family. Conveniently, from the standpoint of being able to make a confident inference about the effects of the social class of adoptive parents, there was no selective placement of children. That is, relatively lower-IQ children were no more likely to be adopted into lowerSES families than were relatively higher-IQ children. So this study reached the same conclusions as the other two French studies: the difference between being raised in a lower-class environment versus an upper-middle-class environment is 12+ points. Note that the study showed that being raised in a relatively modest lower-middle or middle-class family can give a big boost in IQ over being raised in a lower-SES family, namely, 8 points. N o t e also that this study gave, if anything, an underestimate of the effects of being raised in a higher- versus a lower-SES family, because, as Stoolmiller showed, even lower-SES families who adopt have parenting practices of a kind that encourage the growth of intelligence.

Heritability

and

Mutability

35

A review that examined all of the well-designed adoption studies available as of 2.005 found that the effect 011 children's IQ of being adopted by a middle- or upper-middle-class family as opposed to being left behind in the family of origin (which was generally of lower SES) is 1.17 SD, which translates into an 18-point advantage for upper-middle- versus lower-class upbringing. The review also gave an estimate for the contribution of biological factors—genetic plus prenatal, perinatal, and immediate postnatal factors. This estimate was derived by comparing the biological children of middleand upper-middle-class families with their adopted siblings. As it happens, the difference was 12 points, the same value Capron and Duyme found. The crucial implication of these findings is that the low IQs expected for children born to lower-class parents can be greatly increased if their environment is sufficiently rich cognitively. The review of adoption studies tells a somewhat less optimistic story for school achievement. The adopted children performed only .55 SD better in academic achievement measures than their siblings who were not adopted. On the other hand, they scored only about .2.5 SD below the general population and even less behind when compared to their classmates. Before leaving the topic of adoption, I would like to point out that it is customary for strong hereditarians to maintain that the primacy of genes and the low relevance of the environment are established by the fact that there is typically a much higher correlation between biological parents' IQ and their offsprings' IQ than there is between adoptive parents' IQ and their adopted children's IQ. The hereditarians believe that the environment of the adopted child does little for the child's intelligence, since differences in adoptive environments do not make for differences in IQ. We can see now how mistaken this conclusion is. The environments of adoptive families are highly similar for the most part, chiefly consisting of stable middle- and upper-middle-class families. Even adoptive families w h o are of lower SES are high on the parenting practice factors that predict a high IQ. Since variation in adoptive

36

INTELLIGENCE A N D H O W T O GET I T

families is relatively slight, very high correlations would not he expected between the IQs of adoptive parents and those of their children. There just isn't that much difference between the environments of adoptive parents on the dimensions that matter for determining IQ—and if the differences are small, the correlation cannot be big. But there is a huge difference between the adoptive environments on the one hand and lower-SES environments in general on the other, and this results in big IQ differences. So the relatively low correlation between the IQs of adoptive parents and those of their adopted children is nothing but a red herring—it does not contradict in the least the fact that adoptive families are having a huge effect on their adopted children's IQs. Finally, since Herrnstein and Murray assert in The Bell Curve that the "consensus" about the average effect of adoption on IQ is 6 points, it is necessary to point out that their evidence was a review by Charles Locurto. The acttial value that Locurto gave as an average effect of adoption was iz points. The belief that differences between family environments have little effect on IQ has to be one of the most unusual notions ever accepted by highly intelligent people. Judith Rich Harris, the author of the very interesting and best-selling book The Nurture Assumption, premised her work on the assumption that the contribution made by differences between families is virtually nil. In his brilliant book The Blank Slate, Steven Pinker insisted on the same principle. In the best-selling Freakonomics, Steven Levitt and Stephen Dubner were explicit that adoption has little effect on intelligence: "Studies have shown that a child's academic abilities are far more influenced by the IQs of his biological parents than the IQs of his adoptive parents." (I wish I could exempt myself from the company of strange believers, but unfortunately for many years I bought—but was deeply puzzled by—the claims of the hereditarians that family environments do not matter much.) The evidence we have just been looking at concerning the effects of genes versus the environment tells us something crucially important about social class and intelligence. The experi-

Heritability

and

Mutability

37

ences of the children of the professional and middle classes result in much higher IQs and much lower school-failure rates than is typical for lower-SES children. M o r e o v e r , we can place a number, or at least a range, on the degree to which environmental factors characteristic of lower-SES families reduce IQ below its potential: it is between 12 and 18 points. Whatever the estimates of heritability turn out to be, nothing is going to change this fact. So we know that, in principle, interventions have the potential to be highly effective in changing the intelligence of the poor. Interventions could also greatly affect the rate of school failure of lower-class children. T h e minimum estimate for this reduction is about half a standard deviation. T h e maximum estimate for this is much higher—one standard deviation, or about the same rate that would be found for middle-class children raised by their own parents. N o t e also that it is not just the IQs of lower-SES children that can be affected. One study looked at the IQs of white children who were born to mothers with an average IQ and who were adopted by mostly middle- and uppcr-middle-class families. The children adopted relatively late had an average IQ in childhood of 112 and those adopted relatively early had an average IQ of 117. This study suggests that even children w h o would be expected to have an average IQ if raised in an average environment can have their IQ boosted very considerably if they are raised under highly propitious circumstances. Similarly, the cross-fostering study of Capron and Duyme showed that upper-middle-class children can have their IQs lowered if they are raised in poverty. The loss is about 1 2. points. So children born to poor families are not the only ones who can have their IQs dramatically affected by the environment. All children can.

Heritability

Says

Nothing

about

Mutability

N o w 1 can deal a final blow to the idea that high heritability of IQ means that the environment has little effect. The degree of

38

INTELLIGENCE A N D H O W T O GET I T

heritability of IQ places no constraint on the degree of modifiability that is possible. This is so important that I need to say it again, more emphatically: the degree of heritability of IQ places no constraint on the degree of modifiability that is possible. All geneticists accept this principle, but hereditarians often acknowledge the principle and then go on to write as if heritability does in fact place limits on modifiability. To understand why heritability implies nothing about mutability, think about two facts: (a) the heritability of height is about .85 to .90 and (b) gains in average height of a standard deviation or more have appeared in a generation or less in several countries in the world. The average height of thirteen-year-old Korean boys increased by more than seven inches between 1965 and 2.005, a difference of 2.40 SDs. The average boy in 1965 would have been painfully short in 2.005. The forty-year time span is far too brief for genetics to have played a role in the increase. The increases in height we have seen in many places in the world in the last couple of generations are obviously due to environmental changes of some kind, probably in nutrition. Or we can think of an even more extreme case: heritability of 1.0 yet massive environmental influence. We can randomly toss the seeds for corn plants into either rich soil or poor soil. Imagine that the heritability of the height of corn plants is 1.0 in rich soil and 1.0 in poor soil. The average height of the two groups of plants can nevertheless be greatly different and will be entirely due to environmental factors. These examples should make it clear that the heritability of a characteristic within a given population places no theoretical constraint on the modifiability of that characteristic by environmental forces. And that's good, because, as you will see in the next chapter, despite the moderate heritability of IQ, it is enormously influenced by environmental factors—namely, school and the social changes that have taken place over the last eighty years.

CHAPTER THREE

Getting S m a r t e r . . . evert a perfect education system is not going to make much difference m the performance of children in the lower half of the distribution . . .

—Charles

M u r r a y (2007)

... a person's total score [on the Raven Progressive Matrices test/ provides an index of his intellectual capacity whatever his nationality or education. —Raven, Court, and Raven (1975)

holds that nothing in the environment can much affect intelligence. Y o u have the IQ your genes had planned for you. This view has t w o important implications: school should not much affect intelligence; and the intelligence of the population as a whole cannot change a great deal, short of genetic engineering. T H E E X T R E M E H E R E D I T A R I A N VIEW

That such important predictions can be shown to be so manifestly wrong does not happen often in the behavioral sciences.

Does School Make

You Smarter?

Some psychologists have been quite explicit in maintaining that education is mostly irrelevant to intelligence. They hold that education teaches specific facts and procedures but it does not improve raw problem-solving ability to deal with unfamiliar situations. Reflecting the opinion of many intelligence theorists, Herrnstein and Murray, in The Bell Curve, acknowledge that more schooling is associated with higher IQs, but they maintained that the association is in large part due to smarter people deciding to stay in school longer. Smarter people like school better and 39

40

INTELLIGENCE A N D H O W T O GET I T

receive more reinforcement for staying in school and so they get more education. This conclusion is based on regression analyses, which, as I pointed out in Chapter i, are usually unable to answer questions about causality. What happens when education is withheld? Does this prevent people from being as smart as they would otherwise be? Experiments addressing these issues have been tried many times, and the results always turn out to be the same. Evil social scientists do not conduct these studies. Rather the experiments are natural ones in which children are deprived of school for a period of time for a variety of different reasons. Such experiments eliminate the possibility that more schooling is associated with higher IQ simply because smarter people prefer to remain in school longer. Developmental psychologists Stephen Ceci and Wendy Williams have described these studies at length. One natural experiment is summer vacation. Kids are deprived of school over the summer, and this results in a drop or greatly reduced growth in IQ and academic skills. The summer slump is especially great for math, for children in the higher grades, and for children of lower socioeconomic status. Much, if not most, of the gap in academic achievement between lower- and higher-SES children, in fact, is due to the greater summer slump for lower-SES children. The very oldest study on the effect of schooling on IQ was carried out in 192.3. Psychologist Hugh Gordon studied the IQ of the children of transients in London, such as canal boat pilots and gypsies, who went to school rarely if at all. The children's IQ was in the low-normal range around the time they would normally start school, but showed a steady decline thereafter. Children four to six years old had an average IQ of about 90—toward the bottom of the normal range—whereas the oldest children (twelve to twenty-two) had an average IQ of about 60, well below the cutoff for mental retardation. The average IQ of children who attend school doesn't drop. So the study findings indicate that schooling is necessary for children to maintain their intelligence. Another early natural experiment arose from the fact that at the

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beginning of the twentieth century, some children in remote areas of the United States received little or no education. In the "hollows" around the Blue Ridge Mountains, there were children of the original Scotch-Irish and English immigrants whose forebears had departed to the remote highlands when their land was deeded to German immigrants in the nineteenth century. Most of these children had little access to schools, newspapers, or movies. The older the children were, the lower their IQs were, as tested by performance measures (such as a block design test) that do not require literacy. But children in one of these communities did have a reasonable amount of schooling, and their IQs did not drop as they got older. World War II provided another natural experiment. School was delayed for Dutch children for several years by the Nazi siege. The average IQ for these children was 7 points lower than for children who came of school age after the siege. Children of Indian ancestry in many South African villages in the mid-twentieth century had their schooling delayed for up to four years because there were 110 teachers in their village. The IQs of such children, compared to those of children in neighboring villages with access to school, averaged 5 points lower for every year that their schooling was delayed. Even after several years in school, the school-deprived children still had not caught up. Another late-start-schooling study examined black children in Prince Edward County in Virginia, which shut down its public schools between 1959 and 1964 in order to avoid racial integration. The IQs of the children who had no school during that period diminished by an average of 6 points per year of school missed. Dropping out of school early is also bad for intelligence. T w o different groups of Swedish psychologists obtained the IQs of thousands of randomly selected boys who had taken an intelligence test at the age of thirteen. They equated the children for IQ, socioeconomic status (SES), and school grades at age thirteen and then looked at their IQs again when all the boys had to take another intelligence test to register for the military at age eighteen. The psychologists found that for every year of education skipped.

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I N T E L L I G E N C E A N D H O W T O GET I T

there was a loss of about 2. points for boys having the same IQ, SES, and school grades at age thirteen. The loss for boys who dropped our of school four years early was 8 points—equivalent to half a standard deviation. N o t e that these studies established that it isn't just that smarter kids stay in school longer and therefore end up smarter, btit that regardless of what the IQ was at age thirteen, big gains resulted from staying in school. (Or, alternatively, big losses resulted from dropping out. Given the fact that average IQ is forced to be 100, we cannot be sure whether there was a loss for the dropouts, a gain for those who stayed, or some of both.) The fact that children can start school in a particular year only if they are born by a certain date allows for an ingenious way of establishing that school makes children smart. For example, many districts have a cutoff date in September. To illustrate, let's pick the date September i 5. A child born on September 16 has to wait a year longer than a child born on September r5 before she is allowed to start kindergarten. This makes it possible to examine the results of a very tidy natural experiment. We can compare the IQs of kids who have the advantage of being almost a year older than other kids with the IQs of kids who have the advantage of a year's extra schooling. We can then see which is more important: a year of age or a year of school. Sir Cyril Burt and the Ravens and their modern followers are quite clear in their predictions: a year of age for a young child should be worth a lot, and a year of school should be worth little or nothing. ( T o be exact, the Ravens would say that a year of school should be worth nothing for an IQ test such as the Raven Progressive Matrices, which allegedly measures pure fluid intelligence uncontaminated by culture.) In fact, studies in Germany and Israel discovered that a year of school is worth about twice as much as a year of age. Western-style education can have big effects 011 the IQs of children who previously had only non-Western schooling or none at all. Western-style schools improve memory, including memory of the type that IQ specialists often claim is influenced little or not at all by academic learning, such as that assessed by digit span

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(ability to remember digits that are presented by voice) and coding tests (where the child matches symbols with shapes or numbers using a key). As little as three months of a Western-style education improved the ability of African teenagers to perform a variety of spatial perception tasks of the kind found on IQ tests by as much as .70 standard deviation. These included performance tests such as block design, memory for designs, and picture description— tasks that IQ researchers have often characterized as being measures of raw, unschooled intelligence. Given that schools directly teach material that appears 011 comprehensive IQ tests, including information such as the name of the writer who wrote Hamlet and the elements that make up water, as well as vocabulary words and arithmetical operations, it is strange that some IQ theorists doubt that school makes people more intelligent. What is still more surprising to traditional IQ theorists is that school also affects people's ability to solve problems that have been regarded as culture-free, such as those on the Raven Progressive Matrices test. Everyone has had experience with circles and squares and triangles, so many IQ theorists assume that such completely abstract tests are free of the influence of schooling. As you'll now see, it turns out that this assumption is very far off the mark.

Are

We Smarter than

Our Grandparents?

Given that school makes us smart, and given that we have much more education now than people did a hundred years ago, wouldn't it seem to follow that we are smarter than our great-grandparents were? In America in 1900, the mean level of schooling completed was seven years, and a quarter of the population had finished four years or less. The mean today is two years of education after high school, or fourteen years, and the great majority of people complete high school. If you are familiar with the fact that the average IQ has been 100 for almost a century, you might be inclined to assume that education has had no impact on intelligence. But IQ tests are

44

INTELLIGENCE A N D H O W T O GET I T

designed to give an average of 100 by definition, so the constant TOO average actually reveals nothing about change in intelligence over time. To find out whether people get better scores on IQ tests, you would give them the tests that people of a previous time period took, and compare the performance of the group tested earlier with that of the group tested later. This is what happens when tests are re-normed. If the same test were to be given year after year, IQs would become ever higher. To keep the average IQ at 100, new, more difficult items are added to the test. So people are actually doing better with each succeeding year on the kinds of skills that IQ tests capture. For major IQ tests such as the Wechsler Intelligence Scale for Children (WISC), the Wechsler Adult Intelligence Scale, and the Stanford-Binet, the gain has been almost a third of a point per year in the fifty-five-year period between 1947 and 2.002.. This amounts to a total of 9 points per thirty-year generation in the United States. James R. Flynn has documented this increase, which has been christened (not by him) the Flynn effect. The rapid increase in IQ has been found in all developed nations where change has been investigated. In some countries it has been somewhat smaller than in the United States, and in others, somewhat larger. What is responsible for this amazing increase? In what follows I stick closely to the most recent account in an important book by Flynn. One guess about why the gain has occurred is that it might be due to increasing tcst-wiseness—greater familiarity with standardized, paper-and-pencil tests. This explanation is unlikely. The IQ gain has been going on since at least 1917. Scores for eighteenyear-olds on the army's IQ test went up by 1 2. to 14 points between then and the start of the draft for World War II, and people would have had little exposure to standardized tests during that period. The gain in IQ has been more or less constant, covering a period from when relatively few people had experience with standardized tests, to more recent decades, when everyone has had innumerable exposures to them. And in any case, if completely test-naive

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people are given actual IQ tests repeatedly, their IQ scores do go up somewhat, but not a lot. And we are looking at an 18-point gain in the period between 1947 and 2002. H o w about nutrition? This is also quite unlikely. While poor nutrition undoubtedly negatively affects IQ in some parts of the world today, and may even have done so in the United States and Europe before World War II, there is little evidence today of poor nutrition of a magnitude that would likely stunt mental growth for very many people. Most nutrition deficits in developed countries today occur in the prenatal or immediate postnatal period, and while this may have lessened in recent decades, it has been argued that the net effect on IQ of the population has probably been neutral. For every child whose intelligence prospects are improved by better perinatal nutrition, another child has been saved from death but is nevertheless mentally impaired. In any case, in all probability very few children in developed countries have been affected by poor nutrition in recent decades. An additional argument against a role for nutrition is that scores have increased evenly throughout the range for IQ. The IQs of people at the top third of the distribution, for whom there would not have been nutritional disadvantages in any recent era, have increased as much as the IQs of people at the bottom third. The even gains across the distribution of IQ, incidentally, establish that Charles Murray is wrong when he says that nothing much can be done to improve the IQs of people in the bottom half of the distribution. But then what does the gain show? We have to grapple with the meaning of an 1 8-point increase over fifty-five years and a rate of gain of about the same or even more in the preceding thirty-year period. Suppose we take as the real value of intelligence in 1947 an IQ of 100. Typical jobs for a person with an IQ of 100 would include skilled worker, office worker with a not terribly responsible job, and salesclerk. A four-year college would have been very difficult for such a person to handle, even if the person had the means to go to one. The average grandchild of that average person

46

INTELLIGENCE A N D H O W T O GET I T

would have an IQ of i r8 using the same test. A person with an IQ of i i 8 is not only capable of doing excellent college work but is likely to be able to do postgraduate work if that's desired and to become a professional such as a doctor or a lawyer, a high-level manager, or a successful entrepreneur. Is it possible that people have gotten that much smarter on average? Or let's work the numbers back the other way. Say that the true value of an average person's IQ in z o o z was 100. The average grandparent of that average person would have had an IQ of 82. using the version of the test given today to the grandchild. That grandparent would not likely have been able to carry out an office job of much responsibility and would have likely been challenged by the requirements of most skilled labor. Completion of high school would have been an iffy bet. Or let's project back another thirty years to 1917. The greatgrandfather of today's average person would be expected to have had an IQ of 73 using today's test! Skilled labor would have been unlikely for that great-grandparent; high school completion would have been out of the question. And half the population would have been considered retarded by today's standard! Something is clearly desperately wrong with this picture. We are not that smart, and older generations were not that dumb.

In Just What Ways Are We Smarterf On the other hand, we know that we must have gotten smarter because we know that school makes us smarter and we have had a lot more education than otir forebears. So just how much smarter are we—and in what ways? To help us answer this question, let's look at the scores on the W I S C IQ test and on the most widely used "culture-free" test, namely, the Raven Progressive Matrices. Figure 3.T shows the changes in scores over the period 1947—zooz for the Raven matrices; the full-scale W I S C IQ (given to millions of children from six to sixteen years old); the five "performance" subtests of the

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W I S C that measure fluid intelligence (Picture C o m p l e t i o n , Block Design, Object A s s e m b l y , Picture A r r a n g e m e n t , and C o d i n g ) ; t w o verbal subtests of the W I S C that m e a s u r e crystallized intelligence (Similarities a n d C o m p r e h e n s i o n ) ; a n d three other W I S C subtests that measure crystallized

intelligence ( I n f o r m a t i o n , V o c a b u l a r y ,

a n d A r i t h m e t i c ) . N o t e that all s c o r e s o n the tests a n d subtests a r e p r e s e n t e d w i t h the m e a n set e q u a l t o 1 0 0 , t o m a k e c o m p a r i s o n s a m o n g them easier. T h e graph reveals a remarkable p a t c h w o r k pattern. Scores on the R a v e n matrices a n d s o m e subtests of the W I S C h a v e increased markedly while scores on others have hardly changed. Raven Progressive Matrices T h e Similarities Subtest hull Scale IQ The 5 Performance Subtests The Clomprchcmion Subtest Information & Arithmetic &C Vocabulary

Figure Raven United

Let's

3.1. WISC full-scale IQ and WISC subtest scares Progressive Matrices scores from 1947 to zooz for States. Reprinted by permission from Flynn (zooy).

first

discuss

the

allegedly

culture-free

Raven

and the

matrices

(see F i g u r e 1 . 1 ) . T h i s t e s t , w h i c h i s s u p p o s e d t o r e f l e c t r a w i n t e l ligence, that w h i c h is not susceptible to c o n t a m i n a t i o n by culture or school, s h o w s an average gain in intelligence of m o r e than z8 points! G r a n d c h i l d r e n of the person in

1 9 4 7 with an IQ of 1 0 0

n o w h a v e a n a v e r a g e I Q c l o s e t o the o f f i c i a l g e n i u s level a s m e a sured b y that test. W e c a n a b s o l u t e l y rule o u t the p o s s i b i l i t y t h a t p e o p l e ' s real intelligence, d e f i n e d as general p r o b l e m - s o l v i n g ability, a n d s o o n , h a s increased b y that m u c h . W e c a n a l s o rule o u t t h e p o s s i b i l i t y t h a t t h e R a v e n test i s c u l t u r e - f r e e . I t i s a b s o l u t e l y drenched

i n culture. W e k n o w this b e c a u s e g e n e s c a n n o t h a v e

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INTELLIGENCE A N D H O W TO GET IT

c h a n g e d to such a significant degree during that period of time, nor have nutritional standards or any other biological factor that might affect intelligence. S o w h y h a s p e r f o r m a n c e o n t h e R a v e n test i n c r e a s e d s o m u c h ? We don't k n o w , but we can engage in some informed guesswork. D e v e l o p m e n t a l p s y c h o l o g i s t C l a n c y Blair a n d his c o l l e a g u e s h a v e s h o w n that the teaching of m a t h e m a t i c s , beginning very early in elementary school and kindergarten, has shifted f r o m instruction in mere counting and arithmetical operations to presentation of highly visual f o r m s of objects and geometrical figures w h o s e patt e r n s c h i l d r e n h a v e t o f i g u r e o u t . F i g u r e 3.2. g i v e s a n e x a m p l e o f the k i n d of visual d i s p l a y that children h a v e been e x p o s e d to in recent d e c a d e s . Y o u c a n see h o w i t w o u l d b e a n a d v a n t a g e f o r solving actual Raven-type problems. Developmental psychologist

Figure metic from

3.2. Example of a visual problem textbook for very young children. Eicholz (1991).

used it1 a modern arithReprinted by permission

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Wendy Williams has shown that classroom instruction in general emphasizes abstract perceptual tasks much more than in earlier eras. Blair and his coworkers have also shown that math problems are more likely than in the past to require multiple sequential operations of a sort that is essential to the working-memory capacity required to solve Raven problems. But Figure 3.Z shows that it is not merely Raven-type problems but virtually the entire range of performance, fluid intelligencetype skills that have been improved by a culture that has been moving toward ever more visual forms of stimulation—textbooks, television, children's game books, and computers, including computer games. For example, all of the performance subtests of the W I S C have a substantial visual component and many of them require multiple operations that have to be held in working memory for their solution. We have every reason to believe that these sorts of visual exercises actually improve fluid-intelligence skills and the executive functions that underlie them, including working memory and control of attention. Researchers have shown, for example, that video-game players can attend to more things at once than can nonplayers. Video-game players can also ignore irrelevant stimuli more effectively than nonplayers and can see objects in a broader visual field than nonplayers. To make sure that what they have observed of computer-game players is not just a self-selection effect (with the fluid IQ hotshots being the ones most likely to play computer games in the first place), the researchers had nonplayers learn a game—Medal of Honor—that they thought would teach the attention-control skills of their video-game players, and had other nonplayers play a computer game that the researchers did not believe would be capable of teaching attention control, namely, Tetris. Subjects played the computer games for an hour a day for ten days. At the end of the period, Medal of Honor players did better on the attention-control tasks than did Tetris players. Neuroscientists have shown that it is possible to use computer games to train very young children in executive functions of the kind

50

INTELLIGENCE A N D H O W T O GET I T

underlying fluid intelligence. Researcher Rosario Rueda and her colleagues have focused on attention-control tasks. They had four-yearolds work on a variety of computer-based exercises over a period of five days. For example, the children had to keep a cartoon cat on grassy areas and out of muddy ones by using a joystick. The children also carried out anticipation exercises—e.g., learning how to forecast the movement of a duck across a pond—and they performed a task that required them to memorize attributes of different cartoon portraits. And the children had to pick out the larger of two arrays of numbers, with conflict being introduced by having the larger array made up of lower numbers. For example, the child had to pick nine number 4s as being a larger array than five number 7s. The children also had to complete an inhibitory-control exercise. They had to click a picture of a sheep as quickly as possible but withhold the click when the picture was of a wolf in sheep's clothing. These attention-management and executive-control tasks had a very significant effect on children's performance on a matrices task of the kind used in the Raven test. The scores of trained children actually exceeded those for untrained children by more than .40 SD. Remarkably, there was a measurable effect on brain wave patterns. Electroencephalograms were recorded while the children performed some of the tasks. Activity in portions of the brain that mediate attention control was shifted so much that the patterns observed for the trained four-year-old children were more typical of six-year-old children than they were of untrained four-year-old children. So we have every reason to believe that the culture is producing superior executive-control functions than were found for earlier eras, and that these altered executive functions are improving performance on fluid-intelligence tasks—certainly for Raven matrices and probably for other fluid-intelligence tasks such as those in the W I S C performance package. As we might expect, by the way, computer-training tasks like those used by Rueda and colleagues can improve attention control for children with attention deficit hyperactivity disorder ( A D H D ) . The A D H D researchers were also able to improve the working memory of adults without A D H D .

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Cognitive neuroscientist Adele Diamond and her collegues have shown that mundane play activities can also increase executive functions. They structure play for nursery school children in ways that teach attention control and inhibition, crucial aspects of executive functioning. Children plan their play activities in an explicit way, learn to prompt themselves to act in certain ways with the use of memory aids, and get experience in turn-taking. These activities pay off in improving performance on standard executive-function measures. So does the gain of z SDs for the Raven over fifty-five years and the gain of more than i SD for the W I S C performance tests indicate truly massive shifts in intelligence? Probably not. They do indicate huge changes in skills that underlie some kinds of fluid intelligence, but they may not affect problem-solving skills in domains very far removed from those tasks. We don't know how broad a net is cast by these skills at this point. It should be clear that any claims that the Raven matrices comprise a culture-free IQ test are now completely invalidated. Using that test to compare illiterate Amazon tribespeople or Africans with only a little Western-type schooling, with Americans or Swedes or Spaniards living in highly complex and educated and computerized cultures, is no longer intellectually supportable—if it ever was. This is not to say, however, that smarter people within a culture do not do better on the Raven test than people who are not so smart. We know that smarter people do better now and that they did two generations ago. This is because scores on the Raven do and did predict academic competence and career success to a degree. It is just that the Raven and other fluid-intelligence tests are getting easier for everybody in the wake of cultural changes, which include the teaching of mathematics and computer activities. Scores on two tests generally thought of as measuring verbal skills or crystallized intelligence have also improved a lot over time. Performance on the Similarities subtest of the W I S C has increased by an amount equal to 2.4 IQ points over the fifty-fiveyear period from 1947 to 2002. To get a good score on the Simi-

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larities subtest, you have to be able to say that summer and winter are alike because they are both seasons—or if you are really clever, that they both have solstices. Only partial credit is given for saying that summer and winter are times of the year, and none at all is given for saying that "they are parts of nature" or that "they are windy." You also have to be able to say that revenge and forgiveness are alike because, for example, they represent choices about what to do if someone does something bad to you. You get only partial credit for saying that they are both decisions, or they are both actions that you take toward someone, and you get no credit at all for saying that they are feelings or types of resolutions. In short, you have to be able to abstract attributes from the test items and see some intersection of those attributes that is maximally interesting or informative. Does the improvement in performance on the Similarities subtest mean that we have gotten 1.60 SDs smarter in the past two generations? N o , but it does mean that we can think analytically in ways that help us to understand and generate metaphors and similes and that we have gained in our ability to categorize objects and events in ways that are relevant to scientific classifications. And these changes are of real significance. Note that although the Similarities subtest is held to represent a form of crystallized intelligence, and answering the questions correctly does indeed rest on the storehouse of information that a person has, the subtest also has a significant fluid-intelligence component at the level of the more advanced items. You have memorized that summer and winter are seasons, but you have to infer 011 the spot just what features revenge and forgiveness have in common and assess which of those features are the most pertinent. The other crystallized-intelligence subtest showing significant improvement in recent decades is the Comprehension test. In some ways I find this test the most convincing of all to build the case that people really have gotten smarter. It is impressive that young children today are more likely to understand why they should turn off electric lights when they are not using them, and it is impressive

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that somewhat older children are more likely to be able to say why people pay taxes. And the gains are quite significant—one-third of a standard deviation per thirty-year generation. To what should we attribute these gains? I don't know, but I suspect that television has a lot to do with it. Children can learn a lot about the way the world works by watching educational TV shows like Sesame Street and even some shows that are meant purely as entertainment. The changes on the Comprehension subtest arc not likely to be due to increased reading. For an explanation, let's turn to the three crystallized-intelligence tests, which have shown little change over time. The average score on the Vocabulary subtest has increased by a little more than .2.5 SD. This is not nothing, but it is not at all in line with the improvement on the Comprehension subtest. This seems understandable in view of the fact that people read less now than they did in earlier times. The percentage of seventeen-yearolds who read nothing at all for pleasure has doubled over the past twenty years. On the other hand, we do know from other evidence that younger children are learning to read well a little sooner than they did even thirty-five years ago. The National Assessment of Educational Progress ( N A E P ) , which has tested nine-, thirteen-, and seventeen-year-olds every few years since the early 1970s, has established that nine-year-olds are gaining in reading proficiency at a rate of about .2.5 SD per generation. Thirteen-year-olds have gained a smidgen, and seventeen-year-olds nothing. In general, the reading results of the N A E P are pretty much in line with the Vocabulary subtest results. It is worth noting that the negligible improvement for older children is actually better than might be expected given that the level of textbooks for older children in the United States has been dumbed down by about two years in recent decades. What is puzzling is how little improvement—none actually—has been achieved on the Information subtest in two generations. In some ways, this is not surprising in that children spend less time today memorizing facts. I was required to learn all the state capitals. Knowing that the capital of Kentucky is Frankfort and not Lexington has not proved particularly useful to me. On the other hand, it

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is a little puzzling that the average score on the Information subtest has gone up so little while that for Comprehension—understanding of why the world works as it does—went up so much. Another conundrum is posed by the fact that the average score on the Arithmetic subtest of the W I S C hasn't increased in the past thirty years, yet we have other evidence indicating that math skills have genuinely improved. At the turn of the twentieth century, geometry was taught only to college students and upper-level high school students; in midcentury it was not generally taught before the tenth grade; now geometry is taught in the late junior high and early high school years. "Pre-geometry" perceptual material and calculation are taught in elementary school. It was understood in 1900 that calculus could not be taught before the senior year of college, and that was a time when fewer than 10 percent of Americans attended college. At midcentury it was taught in the early years at the better colleges and in the senior year at the best public and private high schools. N o w calculus is routinely taught in the last year of high school, and at some elite schools it is taught as early as junior high. In 192.0 fewer than 20 percent of Americans were educated through high school. By 1983, more than 80 percent were. So it seems very strange that math scores on the WISC have not improved in sixty years. Yet there is substantial evidence that students are in fact better at math, at least prior to high school. The N A E P shows math scores improving by two-thirds of a standard deviation for nine-year-olds in the period 1978—2.004. Scores for thirteen-year-olds improved by more than half a standard deviation. Scores for seventeen-year-olds improved by almost a quarter of a standard deviation. I suspect that the way to reconcile the WISC results with the N A E P results is to note that the W I S C emphasizes rote application of learned arithmetic procedures, whereas the N A E P emphasizes mathematical reasoning and the sorts of multiple-operation problems that put a stress on working memory. But I hasten to say that I am far from confident about how to resolve the discrepancy.

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Will IQ scores continue to go up without limit? Surely not, though there is no evidence of the increase slowing in this country. It does seem to have come to a halt in Scandinavia. In contrast, increases in IQ may have begun in the developing world. In a particular region of Kenya, seven-year-olds gained 1.70 SDs on the Raven Progressive Matrices test over a fourteen-year period and .50 SD on a test of verbal intelligence. Since it was seven-yearolds who were tested, only four months after they started school, it is unlikely that schooling played much of a role in the changes. Access to popular culture of the kind that has been increasing in developed nations, such as video games, accounts for little or none of the gain. Plausible explanations include increases in parental education, which were substantial during the period; improvements in nutrition, which were also marked; and reduced incidence of hookworm. A study on the Caribbean island of Dominica revealed an 18-point gain on the Raven Progressive Matrices and a zo-point gain on a vocabulary test over a twenty-five-year period. What can we say about IQ gains then? 1. School definitely makes people smarter. The information and problem-solving skills learned in school result in a higher IQ score. A year of school is worth two years of age for IQ. 2. People's abilities to perform some of the tasks used to measure IQ have improved over time. This seems inevitable given that more people are getting educated, education is more and more geared toward the kinds of skills that lead to higher IQ scores, and some aspects of popular culture are intellectually challenging. 3. Some of the IQ gains (for example, on the Comprehension and Similarities subtests) clearly amount to real gains in intelligence for dealing with everyday-life problems. 4. Some of the gains in IQ are quite important in that they lead to improvements in academic achievement and should improve the ability to complete tasks involving abstraction, logic, and on-the-spot reasoning—the kind that are encountered in industry and science. Tests measuring such fluid-intelligence gains

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include the Block Design, Object Assembly, Picture Arrangement, and Picture Completion subtests on the WISC, as well as the Raven Progressive Matrices. 5. These fluid-intelligence gains probably don't contribute much to the ability to perform everyday practical reasoning tasks. 6. The gains in IQ make it clear that performance, fluid intelligence—type tests such as the Raven matrices are not culture-free measures of intelligence, a claim some IQ researchers still make. Such fluid-intelligence tasks are much more culture-saturated than are crystallized-intelligence tasks. In fact, the gains on these tests raise a question as to whether a culture-free measure of intelligence is possible. 7. Like the fact that schooling adds points to an IQ score, the fact that gains have occurred over time in skills that society cares about—both for everyday life and for advanced work in science, industry, and other professions—establishes that people can become smarter in very real and important ways. 8. Finally, the evidence speaks against two very pessimistic assertions made by Charles Murray. He has said that even a perfect education is not going to make much difference for people in the bottom half of the IQ distribution. But the average IQ of people in the bottom half has improved by more than a standard deviation in sixty years, and their performance on the Raven Progressive Matrices, the longtime gold standard of IQ, has improved by more than 2. SDs. He has also said that because higher-IQ people have fewer children than do lower-IQ people, the average intelligence of the population must be going down. The evidence suggests the opposite. In the next chapter you will see if it is possible for schools to do an even better job of making people smarter, and in Chapter 7 you will find out if it is possible to bring the IQ of people in the bottom half of the IQ distribution closer to that for people in the top half.

CHAPTER FOUR

I m p r o v i n g the S c h o o l s I took a good deal o' pains with his eddication, sir; let him run in the streets when he was very young, and shift for hisself. It's the only way to make a hoy sharp, sir. — T h e elder W e l l e r , Charles Dickens's

The Pickwick Papers,

1836

smarter over the last century, in part because they have had more and better schooling, can the schools be improved to produce an even bigger boost to intelligence? If so, what can be done to make them even better than they have been to this point? These questions are particularly pointed for Americans because the United States is well behind most of the developed world in its level of educational achievement. U.S. students w h o score in the 95th percentile on general knowledge assessments are comparable to students in the 75th percentile in some of the highscoring countries. T h e most advanced U.S. students, the 5 percent taking advanced placement ( A P ) calculus and the T percent taking AP physics, score about as well as the top 10 to 20 percent of students in other countries. So, even a comparison of top performers reveals a substantial gap between the United States and other advanced countries. IF P E O P L E H A V E B E C O M E

There is plenty of room for improvement, so let's see what might be done to make kids smarter and more academically accomplished.

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Does

Money

Matter?

There is some surprising evidence about what does not work. Since the 1970s, researchers have maintained that the amount of money spent on schools is not very closely related to their effectiveness. This conclusion is usually based on multiple-regression studies in which a large number of variables are put into the analysis to see which ones matter. The studies essentially ask if, net of everything else, the quantity of money spent makes a difference. That amounts to the following: If one is looking at schools where the population consists of rich majority kids in the Northeast, for example, differences in amount of money spent do not matter much, and if one is looking at schools where the population consists of poor minority kids in the South, differences in amount of money spent do not matter much. It seems obvious that the sheer amount of money spent would have no effect by itself on education. Judges sometimes force communities to spend as much for schools attended by poor students as for schools attended by better-off students. Such additional funds may be spent without much careful thought and planning, and when this happens there is little evidence that the scores for the poor improve very much. The classic case of this occurred in Kansas City, where judicial orders increased hugely the amount of money pumped into the schools. Olympic-size pools were built, state-of-the-art science labs were provided, and a computer was given to every student. The result: no improvement in scores. Money by itself does nothing to improve student performance, especially when administrators are incompetent and corrupt, as is the case in some big-city districts. Other evidence about the effect of money comes from a lack of association between the amount of money spent per student in developed nations and achievement scores on tests such as the T I M S S (Trends in International Mathematics and Science Study). Some high-scoring nations are below the median on per capita expenditures, and some low-scoring nations are above the median on per capita expenditures.

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But this does not mean that money never matters. In a later chapter you will find out whether there is any evidence of ways to improve education, especially for the poor and for minorities, by spending more money than we now do.

Vouchers and

Charters

Many school critics have urged a voucher system—giving parents money so they can send their kids to private schools. But researchers should not compare children whose parents are offered vouchers and actually take them with children w h o were not offered vouchers, because of the problem of self-selection: it might be that the more educated, intelligent, and motivated parents make use of the vouchers they were offered. The authors w h o claim that voucher programs have big effects did indeed compare children whose families were offered the vouchers and actually made use of them, with children who were not offered the vouchers. Such studies found as much as a one-third reduction in the black/white gap in test scores. But at least some of this " g a i n " really only represents a difference between children whose parents cared enough to carry through on enrollment and children whose parents might or might not have carried through if given the chance. When researchers maintain that they can control for this effect by procedures such as matching the voucher-users with students whose families were never offered the vouchers but who are comparable on a variety of dimensions, they are talking through their hat. When they let self-selection enter the front door, they cannot get rid of the problem by matching through the back door. In other words, parents who take advantage of an offer that sounds good for their children may be different from otherwise very similar parents in a control group who might or might not have taken advantage of that offer. When studies on the effects of vouchers are done properly— comparing the achievement scores of all children w h o were offered the vouchers (most of whom accept them) with those of

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similar students w h o entered into a lottery for the vouchers but lost and so were not offered the vouchers—the evidence indicates that vouchers result in perhaps .10 SD better performance. (Such a comparison is called an intent-to-treat design: students in the treatment group are included in the analysis regardless of whether they accepted the treatment. This almost inevitably underestimates the treatment effect if there is one, but avoids the deadly self-selection that occurs when the only students compared to controls are those whose parents cared enough to see that they took advantage of the treatment). The disappointing results of this study of course do not prove that private schools are not capable of doing a better job than public schools, just that there is not much convincing evidence that the private schools smdied to date do a better job. There is also little evidence that charter schools in general are particularly beneficial. These schools are publicly funded but have been freed from some of the rules and laws that govern other public schools. In exchange, such schools set out in their charter some assurances of accountability for producing certain results. Reasonable experiments, with random assignment, have compared charter schools with other public schools. Unfortunately, charter schools seem to be only slightly better than the public schools that the children would otherwise have attended—at least for the first few years of their operation. For math and reading, the improvement on standardized tests runs just a few percentile points higher for young students in a charter school. Older students entering a charter school for the first time in later grades actually do worse than the public school students. There is, however, some evidence that after charter schools have been in operation for ten years or so, they may have as much as a 10 percent edge on public schools. N o n e of this should be taken to mean that charter schools cannot do a better job than the public schools—just that not many have to this point. In a later chapter you will see that there is at least one very happy exception to this generalization.

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Class Size H o w about class size? Are smaller classes better? Here we have a real conflict of evidence. The multiple-regression analysts tend to tell us that class size makes little difference to student achievement. On the other hand, economist Alan Krueger, the researcher who has written the most about class-size effects, maintains that 70 percent of studies that looked at class size find a positive effect, and the better the journal in which the study was published, the more likely it was to show a positive effect. And there is one study that, in Krueger's opinion and in mine, is more relevant than all the others put together. For this experiment, which was conducted in Tennessee in the 1980s, teachers and students in kindergarten through third grade were randomly assigned to classes of regular size (twenty-two pupils on average) or to smaller classes (fifteen pupils on average). The children in the smaller classes did better on standardized achievement tests, the improvement varying on average from .19 to .z8 SD depending on subject and class size. In other words, being in a smaller class was typically enough to shift a child on average from the 50th percentile for achievement to a little less than the 60th percentile. The effects persisted to a significant degree through at least the seventh grade. And the effects of a smaller class were bigger for poor and minority children than for middle-class and white children.

Teachers

Matter

H o w about teachers? Do they matter? Surely some teachers are better than others? Indeed so, but the fact that a teacher is certified is not proof that the teacher is particularly good at the job. N o r , surprisingly, is possession of a master's degree. Nevertheless, there is plenty of evidence that teachers can make a difference. First, experience matters. The average difference in reading achievement scores for children taught by teachers with one year versus ten years of experience is .17 SD—an expected benefit

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for experience of about 7 percentile points on achievement tests. But note that most of the difference between more and less experience occurs in the first year of teaching. So it is definitely worth trying to avoid having your child put in a class with a rookie teacher. It is possible to measure teacher quality by defining it as the value a teacher adds to the achievement scores of the average student in his or her class over and above the achievement scores for the average student the previous year. A teacher produces high added value to the extent that students do better than expected given how well the students performed relative to their peers the previous year or years. Defined in this way, 1 SD in teacher quality is associated with approximately .2.0 SD in achievement scores. But this is an estimate of the difference teachers make within a given school. Since we know that teachers in some schools are better on average than teachers in other schools, we can be sure that the within-school difference is a minimal estimate of the difference made by teacher quality. Economist Eric Hanushek's estimate of the impact of teacher quality, across teachers and across schools, is .2.7 SD—more than enough to raise a child from the 50th percentile to the 60th percentile in achievement. The difference in achievement scores that could be expected for a child who had teachers rated 1 SD or more above the mean for quality throughout elementary school and a child who had teachers rated 1 SD or more below the mean for quality is hard to calculate but clearly could be very great. But statistics like these on the quality of teachers pale in their implications beside stories that people tell about the importance of individual teachers to their lives. Most people I know believe that at least one or two of their teachers made a great difference to them, and there is no reason to doubt them. A study 011 the effects of one particular first-grade teacher gives substance to the anecdotes. The teacher, Miss A, taught for thirty-four years in a school serving a low-socioeconomic-status population, a third of whom were black. Sixty students w h o had been at the school over a period of eleven years were interviewed when they were adults. A third of them had had Miss A for a teacher in first grade. Among

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those who had had teachers other than Miss A, 31 percent could not remember the teacher's name. All of the students w h o had had Miss A could remember her name. Whether or not they could remember their teacher's name, only a third of students from the other classes rated their teacher as having been very good or excellent. Three-quarters of Miss A's students gave her a rating that high. Twenty-five percent of children with another teacher gave the teacher an A for effort; 71 percent of Miss A's students did. Asked by a researcher how Miss A taught, a colleague answered, "With a lot of love." The colleague also reported that Miss A expressed confidence that all her students could learn—no child was going to leave her classroom without being able to read. She stayed after school to help slow learners. She shared her lunch with children who had forgotten theirs. Outcomes in elementary school, in youth, and in adult life were much better for Miss A's students. Two-thirds of her former students scored in the top third in achievement in second grade, compared to only 2.8 percent of students of other teachers. The students' status as adults was also measured, by such things as grade of education completed, occupational attainment, and condition of the home. Of Miss A's students, 64 percent were at the highest level of status; of other teachers' students, only 219 percent were at the highest level. This story, inasmuch as it is based on a single individual, could be discounted if there were not other, more convincing, quantitative evidence about the importance of teachers, especially the first-grade teacher. But in fact such evidence exists. Education researchers Bridget Hamre and Robert Pianta had access to the huge longitudinal Study of Early Child Care sponsored by the National Institute of Child Health and Human Development. They tracked about nine hundred children in their progression from kindergarten through the end of first grade. Some of the children were considered to be at risk of poor adjustment to the school situation on the basis of socioeconomic status as indicated by the mother's educational attainment, and some were considered to be at risk

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based on the kindergarten teacher's reports of problems displayed in behavior, attention, and academic performance. The quality of the first-grade experience of each of the children was evaluated by observers sitting in on each class for three hours. The classrooms differed along two related, but somewhat statistically independent, dimensions. The first dimension was labeled "instructional support" and consisted of the sum of ratings of quality of literacy instruction, quality of evaluative feedback to the children, degree to which conversation was concerned with instruction, and encouragement of child responsibility. The second dimension was labeled "emotional support" and consisted of the sum of ratings of emotional climate, effective management of the classroom, involved as opposed to detached relationships with the children, and relative absence of intrusiveness. Classrooms were divided into three levels on the basis of quality of instructional support. All children were tested on a widely Lised measure of ability—the Woodcock-Johnson tests of cognitive ability and academic achievement. When a child who was at risk on the basis of the mother's relatively low educational attainment was placed in a classroom providing low instructional support, the child's achievement score at the end of first grade was more than .40 SD lower than would be expected if the child had been placed in one of the classes having relatively high instructional support. When a child of similar risk was placed in one of the classrooms that provided high instructional support, the child actually functioned at the same level 011 average as children of highly educated parents in those classrooms. Classrooms were also divided into three levels on the basis of quality of emotional support. (In general, classrooms were more likely to be at a high level of emotional support if they were rated high on instructional support and at a low level of emotional support if they were rated low on instructional support, but the overlap was by no means complete.) Children who were at risk of failing on the basis of poor social and emotional functioning in kindergarten, and w h o were placed in a classroom having either

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low or moderate emotional support, scored about .40 SD worse than would be expected if they had been placed in a classroom having high emotional support. Children w h o were at risk on the basis of kindergarten functioning and placed in a highly supportive classroom did just as well as children who were not at risk and were in a highly supportive classroom. The latter finding may be even more important than it sounds. Hamre and Pianta found, in an earlier study, that relationship problems in kindergarten are associated with academic problems throughout school. The findings about teacher quality in the first grade suggest that children with such problems may have a downward path deflected upward very early if they are placed in the right first-grade classroom. Principals know about the quality of teachers in their schools— at least at the extremes. But there is little evidence that principals seek out or reward high-quality teachers. In fact, for teachers in the public schools it would be difficult for them to do so. Union rules tend to enforce similar pay standards for teachers and tend to allow for differences having to do only with seniority, certification, and the possession of higher degrees. There is little evidence, as I have noted, that certification and higher degrees are associated with better teaching, and beyond the first year or so of teaching, neither is seniority. Researchers who are aware of these facts tend to fall into one of t w o policy camps: (1) change the rules and make it possible to reward teachers for good teaching or (2.) concede that this is difficult to accomplish politically and instead focus on teaching teachers how to teach better. Everyone can agree that one of the most important things we can do for education is to improve teaching. Perhaps one place to start would be in schools of education. A common complaint from new teachers is that they received too much theory in education classes and too little experience or practical training. Another route to improving teaching would be to provide incentives for good teaching. Israeli researchers conducted a study of two different incentive programs. One program awarded bonuses to teachers at schools in

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the top third of performance based on their students' achievement. The bonuses amounted to i to 3 percent of base salary. The other program gave greater resources, mainly teacher-training programs and reduced teaching time, to the winning schools. Both programs resulted in improvements in student scores and in dropout rates, but the salary incentive program was the more cost-effective. The study indicates that providing incentives at the school level might avoid union problems. It is conceivable that if such incentives were perceived as add-ons, and winners were at the school level rather than the individual level, teachers and their unions might accept the competition with its reward structure of "possible gain vs. no loss." Just how to assess school quality, however, could be as much a political football as assessing individual teacher quality.

"Effective

Schools"

Until relatively recently, there was little research showing convincingly that some educational techniques are more effective than others. There has long been a huge literature on what are called "effective schools"—schools that go beyond expectations for student achievement. But this evidence rarely rises above the anecdotal. It says that good schools are characterized by principals who convey a conviction that most children are capable of learning; who carefully pick their teachers and carefully monitor them; who find ways to encourage failing teachers to leave the school; who emphasize curriculum and instructional strategies; who monitor student performance data to see if the instructional strategies are working; and who seek parents' involvement in their children's education. Teachers in effective schools are less isolated and are more likely to talk shop; they arc more likely to be evaluated and to appreciate being evaluated; and they monitor student performance data to see if the instructional strategies are working. Much of the literature on effective schools deals with schools serving disadvantaged populations. The usual claim is that schools that emphasize the basics more are more effective with these pop-

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ulations. On the other hand, some people claim that an enriched curriculum more characteristic of good private schools can be highly effective. In short, schools with better outcomes have better principals with better strategies and teachers who are more committed to seeing that their students flourish. But I find little in the literature to convince me that these things cause successful outcomes rather than merely reflecting the fact that the population being served is one that is easier to help. Principals are going to look good if their students are easy to work with. If students are sufficiently troublesome, focusing on curriculum and teacher evaluation may be secondary to enforcing discipline. So while there are many stories about remarkable schools, there are not many hard facts that leave me confident about how to improve underperforming schools.

Educational Research and Its Enemies Despite the hundreds of millions of dollars spent on innovative educational programs, and the hundreds upon hundreds of studies evaluating them, the situation in educational research is scandalous. Research is mostly anecdotal, and most self-styled evaluators of educational programs are actually opposed to the experimental method, that is, providing one educational technique to children randomly selected from some population and providing a comparison technique to other randomly selected children. Very little research rises to the level of being scientifically acceptable. The situation is as shocking as it would be if pharmaceutical companies were to routinely peddle their medicines without having them backed by evaluation research that went beyond haphazardly giving the medicine to some individuals with a given illness and reporting the percentage of patients who got better (without knowledge of the percentage who would have gotten better without any treatment at all). Only drug trials that identify a patient population and then randomly assign some patients to the treatment condition

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and some to the no-treatment or alternative-treatment condition count as adequate research. Yet this standard is almost never met in research on educational interventions. Anyone who tells you that studies lacking random assignment are just as good or better for evaluating educational research should be asked why educational research should be held to different standards than drug research. Plenty of reasons are given for not using the experimental method. There is the claim that ethical considerations demand that the most needy receive the treatment. But ethical considerations reqLiire that the investigators establish that they are doing g o o d — which can be done by finding the most needy and assigning half of them to the treatment group and half to the control group. The most specious reason given is that experiments somehow block finding out just what elements of a treatment cause it to be effective. Without knowing that a treatment is effective, there can be no way of knowing how it is effective. Recent research on schools has employed at least some form of control. In some studies, investigators get schools to agree to accept an intervention, for example, a new type of computer instruction for math, and then compare performance at those schools with that at schools that are similar on a predetermined set of criteria, such as the social class and race of students, but that were not offered the intervention. This type of research is better than nothing, but not by much. It is susceptible to the selfselection problem: the schools that are offered the intervention may be systematically different in some unknown ways from those not offered the intervention. The problem is particularly acute when there is literal self-selection, that is, when only some of the schools offered the intervention accept it. The schools that accept the intervention may rate better on some of the relevant dimensions than those that do not accept it. Also inadequate are studies that simply report scores at a school before the intervention began and compare them with scores after the intervention began. These studies generally yield effect

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sizes that are substantially greater than those found by studies comparing the schools that had the intervention with presumably comparable schools that did not. An exception to this rule exists when gains after an intervention are extremely large—and discontinuous with what could have been expected if there had been no intervention. Under such circumstances a claim of effectiveness can sometimes be persuasive.

Whole-School

Interventions

Some of the programs that have been evaluated are whole-school interventions, known as comprehensive school reform. Educational psychologist Geoffrey Borman and his colleagues reviewed a number of the most promising of these programs, and my account of them rests on their review. I report on only the programs that have had three or more tests by independent third parties, and those in which schools having the intervention were compared to control schools. Virtually none of the comparisons are based on a random assignment of schools or students. One whole-school program—Success for All—has been evaluated twenty-five times in comparison studies by third-party investigators. Hundreds of schools now participate in this program, which is managed by a private foundation. Success for All equips schools with its own curriculum materials, including teacher manuals. It offers a great deal of teacher training in reading, writing, and language arts, as well as twenty-six days of on-site professional development. The program emphasizes assessment of student outcomes and school organization and provides facilitators for each school. One-on-one tutoring is given to students having problems in reading. Outreach to parents is emphasized. Originally the program was available for pre-kindergarten through sixth grade, but it now has a junior high school component as well. Some schools also participate in a broader version of Success for All called Roots &C Wings, which offers programs in math, science, and social studies.

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Success for All seems to make a difference in achievement outcomes, but the better designed and more independent the evaluation, the weaker the effects appear to be—an average effect size of only .08 SD was found across all investigations. A particularly well-designed, fully randomized study, however, revealed an average effect size of .2.7 SD for reading in children assigned to the program from kindergarten through second grade. Moreover, four of the evaluations included the broader Roots &c Wings program, and these evaluations produced an eye-popping average improvement of .77 SD. A couple of highly convincing, independent, random-assignment studies would be required to make an effect this large seem very plausible. Despite all the research, the final word on Success for All is not yet clear. And it will not be until more solid, random-assignment research is done. Another very well-known program, the School Development Program, was founded more than thirty years ago by James Comer, a psychiatrist at Yale University. This program does not specify particular curricula or instructional methods but tries to build good relations among school staff, parents, and communities and sets up health interventions for students. It provides teams that develop and carry out specific reforms related to the assessed needs of individual schools. The third-party comparison studies show an effect of only .1 1 SD. Slightly more successful is the Direct Instruction intervention for elementary schools, primarily those serving a disadvantaged clientele. Direct Instruction reading and math programs are distributed by McGraw-Hill publishing company, and some teacher training is offered. But the full program requires contracting with providers of extensive professional curriculum development and teacher training. The lesson plans are highly scripted and require extensive writing. Lessons are carried out in small groups organized by performance level, and student progress is frequently assessed. The third-party comparison studies show an effect size of .15 SD. The cost of some of the whole-school interventions can be

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rather high. So a thorough cost-benefit evaluation is called for in addition to attending to established effect sizes. In fairness to these programs, and to many others that have been less extensively evaluated, some of the assessments are of interventions that have not been well implemented at some schools in the sample. One can always get null results for an intervention if it is handled badly enough, and the good, the bad, and the ugly all get averaged together to get effect-size estimates.

Instructional

Techniques

A number of studies of specific instructional technologies have also been carried out. Evaluation researcher James Kulik reviewed a large number of so-called integrated learning systems. These computer software systems give students course materials customized to their level of attainment, keep records of how the students are doing, and provide substantial feedback on performance. Kulik reached some very clear conclusions. Across sixteen well-controlled studies of mathematics programs, he found computerized instruction to have a median effect size of .40 SD. This very large effect is educationally significant, and the costs of the program after computer purchase are low. Word-processing programs, by teaching writing, also have a significant effect on learning how to read. The effect may be as much as .2.5 SD in the upper grades and much larger in kindergarten and the first grade. (Computerized reading programs that attempt to teach reading without an emphasis on writing have a median effect size of only .06 SD.) Finally, computer tutoring is apparently effective for teaching the natural and social sciences. The median effect size for those fields was .59 SD, a very significant value. Computer tutoring also resulted in much more favorable attitudes toward the particular science being taught: the effect size was 1.10 SD. Some of the most impressive intervention work to date goes by the name of "cooperative learning." This refers to classroom techniques where students work together in small groups, help-

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ing each other to learn a body of material. The technique can be applied to any subject matter. Students can reach the group's educational goal only if all of them bring their necessary part to the enterprise. It can be used for grades 2. through 12. Education researcher Robert Slavin wrote an entire book on these techniques. In order to be included in Slavin's survey, a study had to have a control group learning the same material, and there had to be an adequate control, either in the form of randomization at the individual, class, or school level, or by means of matching— that is, finding groups of students who were similar 011 many criteria to those who were offered the program. As it happens, results using the far superior randomization methods were approximately the same as results using the matching method. In one variant, Student Teams Achievement Divisions, students are assigned to four-member teams (which arc usually heterogeneous with respect to prior achievement level, ethnicity, or both). The students work together studying the materials and are then assessed individually. Slavin reported studies indicating that this technique has an effect size of more than .30 SD on standardized tests. One particularly impressive technique is the "structured d y a d " method: one student is the tutor and one is the tutored; roles are then switched. There are a variety of ways to accomplish this, but reported effect sizes run very high for all of them. Enough studies of this general technique have been conducted to indicate that instruction in grades 2. through 12 ought to include a cooperative learning component.

Summing Up the Research So what do we have? Can schools apply new procedures and improve their ability to make people smarter? There are lots of answers of the " n o " variety, or at least of the "not yet" or "not much" variety. Money per se does not make a great deal of difference. Vouchers and charter schools have not produced substantially better academic achievement than regular public schools.

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Teacher certification and credentialization are unrelated to student outcomes. Teacher experience does count—at least up to a point: first-year teachers are not as good as they will be, and learning to teach continues for a few years. Teacher quality matters a lot: some teachers are just a lot better than others. But the current systems are not good at rewarding the best teachers or weeding out the worst ones. The research is still young, but there is at least some evidence that providing incentives to teachers at schools that succeed the most results in improved educational outcomes, and it is possible to imagine schemes to give incentives that might not encounter serious political problems. The "effective schools" literature tells us what the principals and teachers at the schools with better outcomes are like, but it does not tell us about causality: To what extent do dedicated principals and focused teachers make for better schools? And to what extent is it the more teachable clientele that makes it possible for principals to look focused and teachers to look dedicated? Some whole-school interventions have been effective, but there is little evidence to date that any of these produce very big effects. Extremely promising evidence shows computerized instruction to be very effective, especially for mathematics and science training. Cooperative learning, in which students work together toward common educational goals, also is very promising. In an extremely welcome development, the U.S. Department of Education now runs what is called the What W o r k s Clearinghouse. This service identifies interventions that evaluation studies have shown to be effective. Unfortunately, the designs of these studies typically fall short of randomized-assignment experiments but at least they are far above the level of anecdotal reports. All of the research conducted for the clearinghouse is supposed to be at least "quasi-experimental studies of especially strong design." These standards are well above most of what passes for evaluation research. We can hope that, eventually, educators will undertake only interventions that have been declared effective

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by the What Works Clearinghouse or will have to answer to an outraged public.

Enriching the

Curriculum: Effects on Skills and IQ

But what would happen if we really pulled out all the stops and tried to teach kids general problem-solving skills that could make them genuinely smarter than they would be by studying materials that are typical for their grade level? A tantalizing answer to this question comes in the form of a massively ambitious study in Venezuela headed by, of all people, Richard Herrnstein, coauthor of the highly pessimistic Bell Curve book. Herrnstein and his coworkers devised a very advanced set of materials geared to teaching seventh-graders fundamental concepts of problem solving that were not targeted to any particular subject matter. In effect, they tried to make the children smarter by giving them handy implements for their intellectual tool kits. The concepts and procedures taught were closer to high school or college level than to junior high level. The researchers gave sixty different 45-minute lessons on topics such as discovering the basics of classification and hypothesis testing, discovering properties of dimensions that can be ordered in some way, analyzing analogies, exploring the structure of simple propositions, understanding the principles of logic, constructing and evaluating complex arguments, learning how to trade off the desirability of outcomes against their probability, and evaluating the credibility and relevance of data. These tools are usually the side effects of learning about a subject or discipline rather than something teachers try to teach explicitly. Can we teach the tools directly—even to children—and show that they generalize to new problems with content different from the problems used to teach them? In a word, yes. The instruction resulted in big changes in children's ability to solve problems that the new skills were designed to improve. Some of the effect sizes were as follows: for language comprehension, .62. SD; for learning how to represent "problem

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spaces," .46 SD; for decision making, .77 SD; and for inventive thinking, .50 SD. In short, general problem-solving skills can be taught, and taught moreover in a brief period of time. H o w about " r e a l " intelligence, as measured by IQ tests? Can teaching problem-solving skills improve IQ? I do not recognize IQ tests as being more than just one particular way to measure intelligence, rather than the way. If we can improve people's reasoning and decision making, I don't care whether this makes them perform better on IQ tests or not. But in fact, on a representative set of general-abilities tests, the score for the experimental group in the Venezuelan study increased .35 SD on average as compared to a control group. On a typical IQ test called the Otis-Lennon School Ability Test, IQ in the experimental group gained an average of .43 SD compared with the IQ in the control group. Even on a highly specialized, largely spatial IQ test similar to the Raven Progressive Matrices called the Cattell Culture Fair Intelligence Test, the gain was .1 1 SD. In short, whether intelligence is measured by general problem-solving skills of the sort that Herrnstein and his colleagues taught or by traditional IQ tests, the training had a very big effect. You will want to know where the investigators went from there. Did they develop a yet more sophisticated tool box for eighthgraders? Unfortunately, the government in Venezuela changed, and increasing the intelligence of junior high school students was no longer a priority. I must say, however, that in light of the spectacular success of the program, it is amazing and dismaying to me that 110 one picked up where the Venezuela project left off.

Effective

Tutoring

Finally, let's remember that a lot of teaching is in the form of one-on-one tutoring. And not surprisingly, tutors differ a lot in their effectiveness. In fact, M a r k Lepper and his colleagues found that college student tutors and other tutors of elementary school students range from virtually ineffectual to extremely

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helpful. And they discovered some intriguing characteristics of effective tutors. First, how do you go about being an ineffective tutor? A surefire way to do it is to regard yourself as a debugger. You explicitly tell the student she has made a mistake and you give direct guidance in how to fix the error, preferably by using an abstractly stated rule. N o n e of Lepper's most effective tutors took such a strictly cognitive, error-correction stance. H o w do you go about being an effective tutor? Lepper gave us five Cs. You foster a sense of control in the student, making the student feel that she has command of the material. You challenge the student—but at a level of difficulty that is within the student's capability. You instill confidence in the student, by maximizing success (expressing confidence in the student, assuring the student that the problem she just solved was a difficult one) and by minimizing failure (providing excuses for mistakes and emphasizing the part of the problem the student got right). You foster curiosity by using Socratic methods (asking leading questions) and by linking the problem to other problems the student has seen that appear on the surface to be different. You contextualize by placing the problem in a real-world context or in a context from a movie or TV show. Expert tutors have a number of strategies that set them apart. They do not bother to correct minor errors like forgetting to put down a "plus" sign. They try to head the student off at the pass when she is about to make a mistake and attempt to prevent it from occurring. Or sometimes they let the student make the mistake when they think it can provide a valuable learning experience. They never dumb down the material for the sake of self-esteem, but instead change the way they present it. M o s t of what expert tutors do is ask questions. They ask leading questions. They ask students to explain their reasoning. They are actually less likely to give positive feedback than are less effective tutors, because, Lep-

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per theorizes, this makes the tutoring session feel too evaluative. And finally, expert tutors are always nurturing and empathetic. All of this could be taught to aspiring tutors—and to aspiring teachers in the schools. In sum: We know that schools can do a lot better job at education than most are doing. We know a lot about what is effective and what is not. There can be no excuses for schools' failure to guide instruction in the light of what research shows to be effective. But instruction is more effective for some clienteles than for others. Let's look at two clienteles in the next t w o chapters and then consider what can be done to improve the situation in the chapter following those.

C H A P T E R FIVE

Social Class and Cognitive Culture . . . the class structure of modern society is essentially a function of the innately differing intellectual and other qualities of the people making up these classes . . . — H . J.

E y s e n c k , The Inequality of Man ( 1 9 7 3 )

about class and intelligence are representative of much of mainstream opinion among IQ experts. Social class is a consequence of intelligence. T h e poor are poor because they are not intelligent, and neither money, nor class, nor parenting practices play much of a role in making some people more intelligent than others. Class is mostly a matter of genes.

T H E V I E W S O F H. J. E Y S E N C K

In the chapter on heredity and mutability, we saw how utterly mistaken these views are. Undoubtedly, people of different social classes have different genotypes for intelligence on average, but there is an enormous causal influence of class 011 intelligence. As we saw in Chapter 2. on heritability, a lower-class child w h o g r o w s up in an upper-middle-class family has an IQ 12. to 18 points higher on average than a lower-class child w h o grows up in a lower-class family. We can estimate that the lower-class families in these studies were at the bottom 15 percent or so of the social-class ladder, and the upper-middle-class families at the top 1 5 percent or so. T h e average IQ for the children of people in the lowest third of the socioeconomic totem pole is about 95, and the average for the children of those in the highest third is about 105. T h a t io-point difference is the result of all factors operating 78

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to push the social classes apart on IQ: genes; prenatal, perinatal, and postnatal biological factors; and all social factors associated with class, including quality of neighborhoods and schools and parenting practices. The results of the adoption studies indicate that postnatal environmental factors—biological and social ones combined—probably outweigh the genetic factors. Eysenck and the other hereditarians could hardly be more wrong. Being poor versus well-off has a huge impact on intelligence. In this chapter I highlight some of the differences in social class that directly influence intelligence. I will not be able to quantify exactly how much difference a particular factor makes. But we know that each of a very large number of factors has at least some influence on intelligence. Moreover, we know that some of these factors would be ameliorated if the poor were better off financially. And we know that there is a lot of room for improvement in the plight of the poor and the working class in the United States. Their economic situation is substantially worse than that in most developed nations. We also know that parenting is different across the social classes. People of lower socioeconomic status (SES) are tacitly preparing their children for different occupational and social roles than are people of higher SES. Educators need to know the ways in which poorer children are ill-prepared for school in order to be able to help them achieve academically. Without improvement in cognitive functioning, countless numbers of poor people will be unable to take advantage of the jobs that exist in the new information economy. First, some definitions. Poor refers to the habitually unemployed, people chronically on welfare, and nonskilled workers. Working class refers to skilled and semi-skilled workers such as mechanics and workers in service occupations and lower-level clerical jobs. I refer to these two classes as one group, lower-SES people. Middle class refers to higher-level clerical jobs, teaching jobs, and supervisory and lower-level managerial positions. Upper-middle class refers to professional and higher-level managerial jobs. I refer to

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these two classes as a group, higher-SES people. These definitions are somewhat arbitrary; there are other ways of carving up the domain of social class, but these definitions map onto the way the social classes were defined in studies referred to in Chapter z. In this chapter the differences I present between lower- and higher-SES people hold regardless of race. In the next chapter I discuss how race and class interact.

Environmental

Factors

of a

Biological

Nature

Being poor is associated with many environmental factors of a biological nature that lower IQ and academic achievement. Some of the differences between people of lower and higher SES may have to do with nutrition. Although the available evidence suggests that poor nutrition in the mother prenatally has no effect on intelligence, when food supplements are given to children who are living in hunger, they show gains in IQ. It is not clear that nutrition differences between the social classes in the West are sufficient to contribute significantly to differences in IQ between the classes, btit there is some hunger among a small percentage of the poor. Even if hunger is rare, we know that lower-SES children are more likely to have vitamin and mineral deficits. And there is evidence that supplements of vitamins and minerals improve the IQs of children w h o are lacking in them. The effects of lead are very deleterious for IQ, and inner-citydwelling kids are exposed to more lead in the form of pollution and old peeling paint than are middle-class and suburban children. Even use of less than t w o ounces of alcohol by pregnant women has a negative effect on IQ. Children whose mothers drank during pregnancy have more difficulty in school because of attention and memory difficulties and poorer ability to reason. Lower-SES women are more likely to drink to excess during pregnancy than are higher-SES women. Lower-SES people have poorer health, and poor health is an impediment to learning in many ways. A sick child will have a

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harder time learning than a healthy one. Specific health problems that are more common among the poor, and associated with low IQ and academic performance, include poor dental health, more exposure to smoke and pollution with consequent susceptibility to asthma, poorer vision, and poorer hearing. Low birth weight is more common for lower-SES babies, and low birth weight is associated with lower IQ. Some pesticides that are being phased out, but are still not uncommon in lower-SES households, are associated with smaller head circumference and lower IQ. One biological factor that may be important is breast-feeding. Lower-SES mothers are less likely to breast-feed. For children with the most common genetic makeups, breast-feeding seems to add about 6 IQ points over and above what the IQ would be without breast-feeding. Breast-feeding may exert its beneficial effect on brain development through the actions of particular fatty acids that are found in human breast milk but not in cow's milk and not in formula. The claim that the relationship between breast-feeding and IQ is causal is still in dispute. One study finds that children who were breast-fed have no higher IQ than their siblings who were not breast-fed. If the relationship is in fact causal, though, it could account for as much as 2 points in the IQ difference between higher- and lower-SES individuals. Medical care is worse for the poor, and this not only compounds the problems associated with poor hearing and vision and asthma, as well as all the other biological factors, but also creates additional problems of its own. Lower-SES people are almost twice as likely to have no medical insurance. Even if they had insurance, working-class parents are less likely to be able to take their children to the doctor because they would lose wages or be absent from work, which would be a cause for discipline. In addition, doctors are much less available for the poor than for the middle class; there are three times as many doctors working around white, nonpoor neighborhoods than around poor, nonwhite neighborhoods. Some of the environmental factors affecting biological pro-

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cesses are severely damaging but uncommon even among lowerSES people, for example, lead poisoning and fetal exposure to alcohol. Some are moderately damaging and are actually fairly common among lower-SES people, for example, exposure to polluted air, which can cause asthma. We do not know exactly how much each of these factors contributes to the IQ and achievement gaps. However, we cannot simply add up the differences made by each one and assume that they account for a very large fraction of the IQ difference between low-SES and high-SES classes. This is because the deficits are undoubtedly correlated with one another—children born to alcoholic mothers are also more likely to be exposed to peeling paint and to have poorer dental health. The deficits can't be regarded as additive.

Environmental

Factors

of a

Social

Nature

Other environmental factors are not biological in the first instance but undoubtedly have seriously damaging effects, possibly mediated by brain physiology. One such harmful circumstance is that lower-SES children move from one house to another much more frequently than higher-SES children. As a result, they have to deal with the stress of moving more often, and they are put into classroom situations for which they are unprepared or are forced to repeat material that they already know. Even when the child stays put, other children are rotating in and out of the classroom and make the environment unstable and teaching more difficult. Lower-SES children are more likely to have behavior problems, which are disruptive to one degree or another for all who have to deal with such children. Instability of all kinds is more common for lower-SES children than for higher-SES children. Lower-class neighborhoods are in general more stressful, and lower-class homes are more susceptible to turmoil and strife. Compared with higher-SES parents, lower-SES parents are less likely to be warm and supportive of their children and are more

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likely to punish infractions harshly. Developmental psychologist Vonnie M c L o y d showed that lower-SES parents arc more likely to raise their children in punitive and stressful ways than is characteristic of higher-SES parents. Early emotional trauma damages the prefrontal cortex, which (you may recall from Chapter i) is heavily implicated in fluid intelligence. We do not know exactly how much stress is necessary to damage the central nervous system, but it is possible that the higher stress associated with lower-SES parenting, together with the other stresses of lower-class life, does produce such damage, at least at the extreme. Fluid intelligence is particularly important to learning and to school achievement in the early grades. Of course, not all lower-SES children have such extreme difficulties. Undoubtedly most have loving families who deal with them in kindly fashion and are deeply concerned with their physical and intellectual development. Many lower-SES children live in neighborhoods that pose few terrors. But at the best, the lowerSES child is likely to have peers who are on average less intellectually stimulating than those available to higher-SES children, and likely also to have to go to schools having poorer teachers, larger classes, worse facilities, and less parental involvement. It is scarcely surprising that a lower-SES environment results in lower IQs and academic achievement.

Class, Money, and the Gap between the United States and Other Developed Countries H o w much would the IQ and achievement gaps be affected if the poor simply had more money? We know that the United States accepts lower levels of intellectual accomplishment for its lower-SES children than do other advanced countries. We need to consider the SES gap in achievement in light of the unusually large economic gap between classes in the United States. Income inequality in the United States is much higher than in most European Union countries or Japan. Although the income per capita

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in the United States is 25 to 35 percent higher than in most other advanced countries, workers in the bottom third of the income distribution are poorer than workers in the bottom third in the European Union or Japan. And workers in the bottom 10 percent of the income distribution of the average European Union country earn about 44 percent more than Americans in the bottom 10 percent. And even this statistic underestimates the disparity between the poorest Europeans and the poorest Americans. Europeans have national health insurance and other economic cushions that most Americans at low-income levels either pay for out of their own pockets or do without. Income disparity is growing at a much faster rate in the United States than in almost any other advanced country. In 1979 the top 10 percent of wage and salary workers earned 3.5 times as much per hour as workers in the bottom 10 percent. Twenty-six years later, the top 10 percent earned 5.8 times as much as the bottom 10 percent. For families with children, the after-tax incomes of the lowest fifth rose by just 2..3 percent in the period T979—2002. In contrast, the after-tax incomes for middle-income families with children rose by 17 percent during this same period. Between 1997 a n d 2.006, the federally mandated minimum wage was never increased. Although an act substantially increasing the minimum wage was passed recently, the minimum wage in 2.009, when the maximum is reached, will be only 73 percent of what it was in 1968 in real dollars. Reflecting the differences in income inequality, there is more skill disparity between the social classes in the United States than there is in most advanced Etiropean countries, as measured by literacy, mathematics, and science scores gathered by the Organisation for Economic Co-operation and Development. Americans in the top fourth of SES scored almost a standard deviation higher than those in the bottom fourth. The comparable difference for the Scandinavian countries was less than two-thirds of a standard deviation. Most of the difference is due to the better performance of Scandinavians in the bottom fourth of the socioeconomic

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distribution. The difference in reading and math skills between lower- and higher-SES groups in the United States is greater than that for twenty-two industrialized countries that have been studied. The difference between the United States and South Korea is even more marked: only a third to a half of a standard deviation separates the average academic achievement of the bottom quarter on the socioeconomic index from that of the top quarter. In fact, the achievement gap between the lowest 2.5 percent and the highest z5 percent of Americans is more similar to that in developing countries than developed countries. There is every reason to believe that the IQ and achievement gaps in the United States could be reduced if people of lower SES had higher incomes. L o w incomes produce many problems, ranging from poorer nutrition and health, to more disruption due to moving from place to place, to lowered expectations for the rewards of education. In a vicious feedback loop, lower income brings lower academic achievement to lower-status American youth, which in turn lowers their value in the labor market, which results in continued lower SES. In a word, if we want the poor to be smarter, we need to find ways to make them richer.

Cognitive

Culture

But other factors that contribute to the test score gap are not so readily cured by money. They concern the parenting practices of the lower-SES population that make learning less likely in the home and more difficult in school—cognitive culture, in short. Higher-SES people start preparing their children for life in the fast lane early on. While their children are still in the crib, higherSES parents begin to push them in directions that put them in good shape for the kinds of questioning, analytic minds they will need as professionals and high-level managers. Lower-SES people are not raising doctors and CEOs; they are raising children w h o will eventually be workers whose obedience and good behavior

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will stand them in good stead with employers who are not looking to be second-guessed or evaluated. Psychologists Betty Hart and T o d d Risley of the University of Kansas carried out an extremely ambitious study of the differences in verbal behavior directed toward children among white professional people, working-class blacks and whites, and underclass, welfare blacks. They observed children and their parents in their homes for many hours. In this chapter I will focus on the differences between professional and working-class families. Professional parents talk to their children more than workingclass parents do. The mother bathes her child in words, with running commentaries about the world, and about her own experiences and emotions, and with questions about the child's needs and interests. The working-class parent talks less to the child, and more of what is said is in the form of demands that would not likely stimulate the child's intellectual curiosity. The professional family includes the child in conversations at the dinner table, often attempting to engage the child in the issues that are being discussed, and exposing the child to vocabulary at the same time. Working-class parents in contrast are more likely to carry on discussions without any assumption that the child would have an interest in the topic or have anything to contribute. The professional parent speaks about z,ooo words per hour to the child, whereas the working-class parent speaks about 1,300. By the age of three, the child in the professional family has heard about 30 million words, and the child in the working-class family has heard about 2.0 million. The resulting vocabulary differences are marked. By the age of three, the professional child has command of about 50 percent more words than does the working-class child. Parents differ in how they deal with their children emotionally too, in ways that likely play a role in developing their intellectual interests and achievement. The professional parents made six encouraging comments to their children for every reprimand. The working-class parents gave only two encouraging comments per reprimand. Degree of encouragement by parents is associated

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with intellectual exploration and confidence on the part of the child—and the children of professional parents are way ahead of the game in this respect.

Middle-Class Parenting: Encouraging Analysis of the

World

Much of what we know about social class and children's preparation for literacy and school life comes from the classic study of socialization by anthropologist Shirley Brice Heath. Heath spent many months in a town in North Carolina studying white middleclass families (all of whom had a teacher for a mother or a father), white working-class families (in most of which the father worked in the local textile mill), and black working-class families ( w h o were mostly farm workers, mill workers, or welfare recipients). Heath literally lived with the families, observing them during all hours of the day and night and following the children to school. She found very large differences in the literacy-related activity of the three groups of children and in their preparation for elementary school. Heath's study was conducted in the late 1970s and her evidence base is just a small number of families in a particular community, but more recent studies, with a larger number and wider range of participants, found parenting practices differing across social classes in much the same way that Heath reported. In what follows, I rely primarily on Heath's work and the more recent work of Annette Lareau. The middle-class parent reads to the child much more than does the working-class parent. There are lots of children's books in the middle-class home. Reading to the child begins as early as six months, as soon as the child can be propped up to look at a book. And the middle-class parent reads to the child not just as a form of entertainment but also to encourage connections between what appears on the page and what exists in the outside world. There is a deliberate effort to take what is read in books and relate it to objects and events in daily life and in the world. ("Billy has a black dog-

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gie. W h o do you know who has a black doggie?" "That's a robin. Where did we read about robins? What do robins eat?"). Parents also encourage analysis of what is read ( " W h a t will happen next? What does she want to do? Why does she want to do that?"). From a very early age the middle-class child expects to be asked questions about books and knows how to answer them. Parents ask their children about the attributes of objects and teach them how to categorize objects based on their properties. (I once sat on a plane behind a father and his three-year-old son. The father had a picture book and was asking the child whether particular objects were long or short. " N o , Jason, pajamas are long.") Middle-class parents also ask what questions ("What's that?" " W h a t did Bobby try to d o ? " ) and follow them with why questions ( " W h y did Bobby do that?"), and later with requests for evaluations ("Which soldier do you like better?" " W h y do you like him better?"). Adults encourage their children to talk about what is in their books and even to tell stories that are inspired by the ones they have read. Middle-class children are well prepared for school. They know how to take information from books, they expect to be entertained by them, and they are familiar with how to answer socalled known-answer questions—that is, questions whose answer is known to the questioner. The early grades go easily for such children. They are also more than ready for the later elementary years, when analysis and evaluation are called for.

Working- Class Parenting: Socialization for the Factory The working-class baby is brought home to a house with some children's reading material—Little Golden Books and perhaps some Bible stories, maybe a dozen books all told. Walls are decorated with picttires depicting nursery rhymes, and there is probably a mobile. Family, friends, and neighbors talk to the child. Although working-class children are asked questions about what is read to them, there is not much effort to connect what is

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on the page with the outside world. A book might have a picture of a duckling, and the mother might ask the child if he remembers the duck he saw at the lake, but then she might not explain the connection between the fuzzy yellow duckling on the page and the full-grown mallards at the lake. After about the age of three, children are not encouraged to carry on a dialogue with the reader. Instead they hear, " N o w you've got to learn to listen." The child is supposed to pay attention, and comments or questions are regarded as interruptions. (A Philadelphia study illustrates both a symptom and a cause of the social-class difference in literacy. In areas where almost all adults are college-educated, booksellers had 1,300 children's books available per 100 children, whereas in blue-collar Irish and Eastern European neighborhoods only 30 children's books were available per 100 children. There could scarcely be a more stark set of figures capturing the social-class literacy gap.) Activities in the middle-class family are guided by words. The middle-class father showing his child how to bat a baseball says, "Put your fingers on top of each other around the bottom of the bat; keep your thumb in this position here; don't hold it above this line; don't leave the bat on your shoulder—hold it above your shoulder a couple of inches." The working-class child gets no such elaborate instructions or experience in how to translate verbal instructions to physical practice. Instead the child is simply told, " D o it like this; 110, like this." The middle-class family, when starting to play a new game, reads the instructions aloud and comments on them. The working-class family is more likely to guess at how to play the game and start playing it, making up rules as they go along. The middle-class mother works from a recipe, which she may read out loud so her child can make connections between what is read and what materials are being used and which procedures are being carried out. The working-class mother is less likely to use a recipe, and unlikely to give her child an opportunity to make connections between it and the materials at hand when she does use one.

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Working-class children come to school with sufficient preparation to do reasonably well in the early years. They often know the alphabet; they can name colors and numbers and they can count; they can tell someone their address and their parents' names. They can sit still and listen to a story, and they know how to answer what questions about factual matters. But when they are asked, " W h a t did you like about the story?" not many have ready answers. When asked, " W h a t would you have done?" they are usually stumped. When categorization and analysis and evaluation are emphasized in the later elementary grades, such children are at a decided disadvantage. When they are asked to write a story, they are likely to merely repeat some story they have been read. When asked about counterfactuals—"What would have happened to Billy if he hadn't told the policemen what happened?"—they are at a loss. Children who face these difficulties are likely to be demoralized and alienated by junior high school and are on their way toward being candidates for dropping out of high school. The differences between the social classes that Heath found in socialization for literacy and school helps us to understand what happens to children's IQs and academic skills over the summer, when they are not in school. The IQs and skills of middle-income children generally stagnate during this time. But there is a drop in skills for lower-SES children, whose families would not be expected to provide the degree of cultural stimulation over the summer that middle-class families do. The middle-class kids do not fall behind much during the summer because, undoubtedly, they engage in more educationally valuable activities, like reading and being read to, listening to stimulating conversation at the dinner table, going to museums and zoos, and taking classes in art, music, and even academic subjects. One study found that of children who are in transition between kindergarten and first grade, those in the highest quintile of SES actually show an increase in skills over the summer, whereas kids in the lowest SES quintile show a substantial decrease. So a significant portion of the differ-

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ence in IQ and academic skills between upper-middle-class children and lower-class children can be attributed to the cumulative drop over the summer for lower-SES kids, which they never quite make up for during the school year. The hereditarian reading the chapter to this point might be thinking, " H o w do we know that these differences in socialization practices actually play a causal role in the intelligence and achievement of children? H o w do we know that it isn't simply that higher-SES people have more intelligent children than lower-SES people, not just because of what the environment does to them, but simply because they have their parents' fortunate genes? And parents with smarter genes do intellectually stimulating things for their kids all right, but this is because their genes make them enjoy doing those things and the children are more rewarding to do those things with because they're smarter." Undoubtedly, what the hereditarian says accounts for a nontrivial portion of what is going on. The environmental differences are to some degree a consequence of higher-IQ genotypes from upperSES parents and lower-IQ genotypes from lower-SES parents. But remember that genetics cannot be a very large part of the explanation of the IQ and achievement gap. The purely environmental contribution to the gap between the highest- and lowestSES groups (probably roughly the highest and lowest i 5 percent) is 1 2. to 18 points. That does not leave a lot of room for genes. The gap between the lower third in SES and the upper third is 10 points, and we know that a substantial portion of that has to be due to environmental differences. Our confidence about the very substantial role of the environment is crucial to keep in mind for when I discuss in a later chapter how much we might expect to improve the intelligence of working-class and lower-class children. Both because of the adoption studies discussed earlier and because of the litany of environmental factors that I have recited in this chapter, we know that there is lots of room for improvement in the environment to make a difference.

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Improving the economic situation of the poor would undoubtedly make a big difference. On the other hand, there would not necessarily be big improvements in the IQ and academic achievement of lower-SES children in the first generation after economic advancement, if that were to take place. Generals prepare for the last war, and parents socialize for the life situations of their parents and not so much for their own or their children's. In fact, there is some evidence that in the first generation after additional income is made available to families, the improvement in intellectual status of the children is slight. Gains due to improvement in income alone are likely to be incremental across generations. Fortunately, as you will soon see, the schools can be made to speed up the process of reducing the gap between the social classes, putting lower-SES children in a much better position to take advantage of the opportunities available in the informationage economy. But first, let's look at the gaps between the races in IQ and academic performance. Some of the reasons for the gaps are the same as those for the SES gaps, and some are different.

C H A P T E R SIX

IQ in Black a n d W h i t e The taboo against discussing race and IQ has not left this an open question. On the contrary, it has had the perverse effect of freezing an existing majority of testing experts in favor of a belief that racial IQ differences are influenced by genetics. No belief can be refuted if it cannot be discussed. — T h o m a s Sowell (1994)

I Black] kids seem to . . . have . . . this unconscious way of thinking that Blacks are inferior to Whites. And I think that takes a toll.

— B l a c k male h i g h school s t u d e n t in O h i o

inter-

v i e w e d b y a n t h r o p o l o g i s t J o h n O g b u (2.003)

whether there are innate differences in intelligence between blacks and whites goes back more than a thousand years, to the time when the M o o r s invaded Europe. T h e M o o r s speculated that Europeans might be congenitally incapable of abstract thought!* But by the nineteenth century most Europeans probably believed that they were genetically superior to Africans in intellectual skills.

THE Q U E S T I O N OF

The IQ test, developed early in the twentieth century, reinforced the genetic view. Since whites scored higher than blacks, many psychologists, basing their hypothesis on the assumption that IQ is largely heritable, assumed that the black/white group differences were genetic in origin. For decades, whites scored an average of 100 points on IQ tests, while blacks scored about 85—a difference of 15 points or

* A m i l l e n n i u m earlier s o u t h e r n Europeans h a d their d o u b t s a b o u t n o r t h e r n Europeans. C i c e r o w a r n e d t h e R o m a n s n o t t o p u r c h a s e t h e B r i t i s h a s slaves b e c a u s e t h e y w e r e s o d i f f i c u l t t o t r a i n , t h o u g h Julius Caesar felt they " h a d a c e r t a i n value f o r r o u g h w o r k . " 93

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a full standard deviation. If such a difference were wholly or substantially genetic in origin, the implications for American society would be dire. Even if the environmental playing field were leveled, a much higher proportion of blacks than whites would have trouble supporting themselves, and a much lower proportion of blacks than whites would be capable of being successful in business or the professions. In this chapter I review the evidence about the role of genetics in producing differences in IQ between blacks and whites. I also show that there remain serious societal roadblocks, as well as some social practices characteristic of African Americans, that make educational and occupational advancement less likely.

Not in the Genes Laypeople differ markedly in whether they think race differences in IQ have a partly genetic origin or a purely environmental origin—and so do behavioral scientists. Some laypeople I k n o w — and some scientists as well—believe that it is a priori impossible for a genetic difference in intelligence to exist between the races. But such a conviction is entirely unfounded. There are a hundred ways that a genetic difference in intelligence could have arisen— either in favor of whites or in favor of blacks. The question is an empirical one, not answerable by a priori convictions about the essential equality of groups. As it turns out, there is a great deal of empirical evidence on the question. In 1994, psychologist Richard Herrnstein and political scientist Charles Murray published The Bell Curve, which maintained that black IQs were clearly lower than white IQs. They presented what they maintained was a balanced view of evidence pointing to the conclusion that the IQ difference between the races was substantially genetic. Charles Murray—Herrnstein died at the same time that The Bell Curve was pLiblished—has repeatedly claimed that the book was agnostic with respect to the degree of genetic contribution to the difference. The evidence presented in the book,

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however, is clearly weighted in favor of the genetic view. Both the public and most of the scientific community have concluded that the book endorsed the view that the black/white difference was probably substantially genetic in origin. In this chapter and in Appendix B I present the arguments for genetic determination of the black/white gap made by Herrnstein and Murray in their book, and by J. Philippe Rushton and Arthur Jensen in their sixty-page review of the evidence published in 2005. The appendix is not intended for the general reader but rather for the specialist who would like to see the entire ease against the genetic argument. The black/white gap is not due to some obvious artifact, such as blacks not being familiar with formal English, or being less motivated to perform on IQ tests, or having teachers or IQ testers who have low expectations for their performance. There is plenty of evidence though, that blacks sometimes perform worse on IQ tests and achievement tests when their race is made salient and this engages a "stereotype threat," causing them to perform worse than they would in more relaxed settings where they are not afraid of confirming a stereotype that white testers have. Social psychologists Claude Steele and Joshua Aronson demonstrated this, and countless subsequent studies have confirmed the point. The underperformance is most likely when blacks are tested in an integrated setting and it is made explicit that it is intellectual ability that is being tested. When the test is presented as a puzzle, or when blacks are assured that blacks and whites do equally well on the test, black performance typically is better than in more threatening circumstances, sometimes markedly better. In general, it is not the case that blacks perform better either at school or at work than would be indicated by their IQ scores. At least as late as 1980, when Jensen reviewed the question, academic performance and occupational outcomes for blacks were actually lower than would be predicted by their IQ scores. At a given IQ level, whites perform better than blacks. Blacks have lower socioeconomic status (SES) on average, and

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people with low SES have lower IQ test scores. But that fact by itself does not speak to the heritability issue, because it is not clear to what extent low SES drives IQ lower versus to what extent low IQ drives SES lower. We do know that blacks have lower IQs than whites at every level of SES, so SES cannot be the full explanation of the black/white IQ difference. The hereditarians have come up with a raft of evidence that the black/white difference in IQ is genetically based. But all such evidence is indirect. There is, for example, the evidence that brain size is associated with intelligence. The correlation between brain size and IQ may be as high as .40. And according to a number of studies by Rushton, blacks have smaller brains than whites. The correlation between brain size and IQ does not indicate a causal relationship, however. If bigger brains were smarter because of their size, then we would expect to find a correlation within families. Siblings who get the larger brains by luck of the genetic draw should also be the ones who have higher IQ scores. In fact, however, there is no such correlation. Moreover, the brain-size difference between men and women is substantially greater than that between blacks and whites as reported by Rushton and Jensen, yet men and women score the same, on average, on IQ tests. And a group of people in a community in Ecuador have a genetic anomaly that produces extremely small head sizes—and hence brain sizes—yet their intelligence is as high as that of their unaffected relatives, and their academic achievement is substantially greater than that of most people in their communities. The direction of recent evolution over the last few thousand years, incidentally, is toward smaller brain sizes for humans. And I note just for interest's sake that Albert Einstein's brain was decidedly smaller, at 1,2.30 grams, than the overall average found for blacks in the studies by Rushton. Most of the evidence that the hereditarians present is indirect in the same way that the brain-size evidence is. It is not necessary, however, to rely on indirect findings when we have much more

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direct evidence about the basis for the IQ gap. A natural experiment allows us to test whether European genes make for higher IQs than African genes. About 2.0 percent of the genes in the American black population are European, meaning that the genes of any individual can range from being 100 percent African to mostly European. If European genes for intelligence are superior, then blacks who have relatively more European genes ought to have higher IQs than those who have more African genes. One test of this hypothesis is to determine whether the physical features of blacks that indicate more European heritage are associated with higher IQs. It turns out that light skin color and stereotypically Caucasian features—both measures of the degree of a black person's European ancestry—are only very weakly associated with IQ (correlations in the .TO to .15 range), even though we might well expect a moderately high association due to the social advantages of these characteristics. Another test of the genetic hypothesis occurred as a result of World War II, when both black and white American soldiers fathered children with German women. Thus some of these children had 100 percent European heritage, and some had substantial African heritage. Tested in later childhood, the German children of the white fathers had an average IQ of 97.0, and those of the black fathers had an average of 96.5, a trivial difference. If European genes conferred an advantage, we would expect the smartest blacks to have substantial European heritage. But when a group of investigators sought out the very brightest black children in the Chicago school system and asked them about the race of their parents and grandparents, they found that these children had no greater degree of European ancestry than blacks in the population at large. Blood-typing tests have been used to assess the degree to which black individuals have European genes. The blood group assays show no association between degree of European heritage and IQ. Similarly, the blood groups most closely associated with high

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intellectual performance among blacks are no more European in origin than other blood groups. One way of testing the heredity-versus-environment question is to look at black children raised in white environments. If the black deficit in IQ is due entirely to the environment, then blacks raised in white environments ought to have higher IQs than those raised in black environments. T h e hereditarians cite a study from the 1980s showing that black children who had been adopted by white parents had lower IQs than white children adopted by white parents. Mixed-race adoptees had IQs in between those of the black and white children. But, as the researchers acknowledged, the study had many flaws; for instance, the black children had been adopted at a substantially later age than the mixed-race children, and later age at adoption is associated with lower I Q . A superior adoption study was carried out by developmental psychologist Elsie M o o r e , w h o looked at black and mixed-race children adopted by middle-class families, either black or white, and found no difference in IQ between the black and mixed-race children. Important recent research helps to pinpoint just what factors shape racial differences in IQ scores. Psychologists Joseph Fagan and Cynthia Holland tested black and white community-college students on their knowledge of, and their ability to learn and reason with, words and concepts. The whites had substantially more knowledge of the various words and concepts, but when participants were tested on their ability to learn new words, either from dictionary definitions or by learning their meaning in context, the blacks did just as well as the whites. Whites showed better comprehension of sayings, better ability to recognize similarities, and better facility with analogies when solutions required knowledge of words and concepts that were more likely to be known to whites than to blacks. But when these kinds of reasoning were tested with words and concepts known equally well to blacks and whites, there were no differences.

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Within each race, prior knowledge predicted learning and reasoning, but between the races it was only prior knowledge that differed, not learning or reasoning ability. it seems unlikely that differences in knowledge would have a genetic basis if there are no differences between the races in learning and reasoning ability. It seems much more likely that the knowledge differences are entirely due to environmental effects. (However, 1 would never argue that knowledge differences do not count as intelligence differences. Intelligence depends to a substantial degree on knowing words and concepts.) The Fagan and Holland research is extremely important, but replication with different kinds of materials and different participants is in order before we can be completely confident about its implications. Some of the most convincing evidence about whether the IQ gap has environmental causes concerns Flynn's discovery about IQ changes over recent generations. This research, described in Chapter 3, established that in the developed world as a whole, IQ increased markedly from T947 to 2002. In the United States alone, it went up by 1 8 points. Genes could not have changed enough over such a brief period to account for the shift; it must have been the result of powerful social factors. And if such factors could produce changes over time for the population as a whole, they could also produce big differences between subpopulations at any given time. Indeed, black IQ now is superior to white IQ in 1950. If black genes for IQ are inferior to white genes for IQ, that could not happen—unless you wanted to argue that the environment for blacks today is far more conducive to high IQ than the environment for whites in 1950. I doubt that many people would attempt to make that argument. Finally, since there is good reason to believe that the environment of blacks has been improving at a more rapid rate than that of whites, the black/white gap should be less today than in the past. In fact, we know that the IQ difference between black and white twelve-year-olds has dropped to 9.5 points from 15 points

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in the last thirty years—a period that was more favorable for blacks in many ways than the preceding era. Black progress on the National Assessment of Educational Progress ( N A E P ) Long-Term Trend test shows equivalent gains. Reading and math improvement has been modest for whites but substantial for blacks. The shrinkage of the gap on the N A E P is roughly equal to the 5.5 points found by Dickens and Flynn for IQ tests. It is hard to overestimate the importance of a gap reduction of this magnitude. When population means differ, the differences at the tails of the bell curve are very great. If whites score higher than blacks by an average of 1 5 IQ points—the difference between the t w o groups in the past—people with IQs of 130 and above are about 18 times more likely to be white than black. That would mean that successful doctors, scientists, and professionals would be enormously more common among whites than among blacks. But if the difference is 10 points, the ratio of whites to blacks is more on the order of 6 to 1. Whites would be much more common at the highest levels of achievement, but the difference between the t w o groups would not be as great. Differences at the other end of the IQ scale are equally marked. If the group difference is 1 5 points (blacks scoring lower than whites), people w h o will not be able to fend for themselves economically are vastly more likely to be black than white; if the difference is 10 points, such people are merely substantially more likely to be black than white.

Barriers

to

Accomplishment for

African

Americans

So why is it that blacks historically score poorly on IQ tests, achieve low levels academically, and attain relatively low levels of occupational success? The evidence indicates that genes play 110 role in these facts. So we can assume we have a purely environmental story to tell. First, all of the problems of lower-SES people that affect ability and achievement are often exacerbated for blacks, who are overrep-

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resented among the poor. To remind you of just what those potential problems are: They include poor prenatal care and nutrition, relative infrequency of breast-feeding, hunger, deficiency of vitamins and minerals, lead poisoning, fetal alcohol poisoning, poorer health care, greater exposure to asthma-causing pollution, emotional trauma, poor schools, poor neighborhoods along with the less desirable peers who come with the territory, and much moving and consequent disruption of education. For the black underclass these problems are worse than they are for poor whites. Additional problems also exacerbate the black situation. Black family income in 2001 was 67 percent of white family income, but black family wealth was 12 percent of white family wealth! Part of the reason for this discrepancy is the practice of " r e d l i n i n g " — keeping blacks out of white neighborhoods where property values produce a greater return on investment. Thus for blacks in general, there is very little cushion to fall back on in times of underemployment or unemployment. For lower-class blacks there is next to nothing. Moreover, the wealth differences reflect the fact that most blacks who are in the middle class have only just arrived there. We can expect that their parenting practices are going to remain more similar to that of the lower class than is the case for the typical middle-class white. The unwed mother rate is 72 percent for blacks, compared to Z4 percent for whites. This statistic represents a host of problems for black children, not least of which is that the poverty rate for single-parent homes is far higher than it is for two-parent homes. Perhaps equally important is the fact that such homes have only one adult, and the fewer adults there are, the less stimulating is the environment. The economic situation for blacks is not static. T w o different trends are developing in the black community in the United States, one favorable and one highly unfavorable. First, more and more blacks are moving into the middle class, and those already there are strengthening their economic circumstances. Affirmative action has likely played a role in these gains

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(though some researchers argue that substantial progress occurred for blacks before affirmative action became common). A second trend is that the economic situation is getting relatively worse for blacks who remain in the lower class, just as it is for lowerSES people in general. Recall from the last chapter that real income is lower for the poor and for working-class people than in the past. For lower-SES blacks, affirmative action has had little effect. So the financial situation is worse for a large portion of the black population, especially young black males, than it was in the past. The motivation to work, particularly for young black men, is undercut by societal attitudes that this group is not to be trusted. Employers believe that young black men are less dependable, enthusiastic, cooperative, and friendly, are less capable of working with teams, and have poorer communication skills. Unfortunately, there is evidence that employers are not capable of setting this stereotype aside even when presented with an individual who clearly contradicts it. When black and white job applicants with similar credentials apply for jobs, the white applicants do much better. An experiment with black and white college graduates posing as applicants for entry-level jobs is particularly chilling. The young men, all of whom were well groomed and articulate, presented themselves as high school graduates with identical qualifications. The white applicants who admitted to a felony conviction got more positive responses than did blacks with no such blot on their records. So powerfLil stereotypes brand even the black male who is a high school graduate. This means that, realistically, a diploma has less value for black males than for white males. It would scarcely be surprising if this lowers the incentive for black males to complete their education. It makes sense, then, that black females do far better educationally than black males, and consequently reach higher occupational levels. Already in T965, at the time of Patrick Moynihan's well-known report on the status of black families, black females were 30 percent more likely to graduate from high school than black males. In 2.005, f ° r blacks twenty-five to

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twenty-nine years old, the ratio of females to males with a college degree was 1.69 to 1. Since we know that more schooling and more serious attitudes toward school make people smarter, it comes as 110 shock that as of about 1980 black females were twice as likely to have an IQ above 120 than were black males. There is of course no conceivable genetic explanation for such gender differences, given that there is no mean difference in IQ between white males and females and given that, for whites, males are more represented at the high end of the IQ distribution (as well as at the low end, which is how the average can come out to be the same). As a consequence at least in part of their superior educational credentials, black women are twice as likely to have white-collar jobs in the federal government as are black men. So not only must lower-SES blacks face all the hardships of their social class, but also they face a separate host of problems owing to their race. SES is worse for blacks than for whites, and prejudice is devastating for large swaths of the black population, reducing their ability to get decent jobs and sapping their motivation to complete their education.

The Caste System in America for Blacks and "Former Blacks " Race may be an "American dilemma," as the title of a classic work by Gunnar Myrdahl suggests, but the problems of lower castes throughout the world are similar to those of American blacks. African anthropologist John Ogbu has reviewed evidence showing that caste-like minorities such as the Maori in N e w Zealand, the Burakumin in Japan, Catholics in Northern Ireland, Sephardic Jews in Israel, and scheduled castes ("untouchables") in India are characterized by poor school performance, high likelihood of dropping out of school, low IQ test scores, and high levels of crime and delinquency. The IQ differences between higher and lower castes in India exceed the largest differences reported

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between blacks and whites in the United States. Moreover, many non-African groups in the world have recorded average IQs of 85 or lower—less than the value commonly given for blacks in the United States in the past and substantially less than the contemporary value for blacks. These groups include whites in some Appalachian Mountain communities in the early-twentieth century, the children of the first wave of Italian immigrants to the United States, canal boat communities in Britain, and inhabitants of the Hebrides islands off Scotland. Ogbu focuses 011 what he calls "involuntary" minorities, those like American blacks who were brought by force to America. He contrasts them with what he calls "autonomous" minorities, whose members are separate from society by choice, such as Mormons and the Amish, and with immigrant minorities. Immigrants tend to compare themselves not with the majority in the new country but with their peers in the old country, and they find themselves better off. Unlike lower-caste minorities, immigrant minorities tend to have lower rates of crime than the host population. (Though their children have higher crime rates, probably in part because they do compare their situation unfavorably with that of the majority in the society.) Ogbu holds that caste-like minorities often fail to take full advantage of the opportunities that are available to them because they do not have " e f f o r t optimism"—that is, they lack conviction that their efforts will be rewarded. A frequent consequence of this lack of faith in the system is that they do not work hard in school because they do not expect the work to be rewarded. Younger members of the minority may even invert the educational values of the society. In the case of American blacks, the young may reject academic earnestness as "acting white." Ogbu has written for decades about the attitudes of young blacks, especially males. Young black students, even middle-class ones in middle-class schools, are more likely to come to class without having done their homework, and they are more disruptive. A surprising number think they can go to college on athletic scholarships and so

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they do not need to make good grades. They are likely to avoid taking academically challenging courses even when encouraged to do so by teachers and counselors. Knowledge of the cultural history of blacks in the United States is important to understanding race problems today. Here I review some of that history and compare it with the history of another group that was formerly the target of great prejudice— Irish Americans. In the nineteenth century in the North it was far from clear whether the Irish or the blacks would be better off by the twenty-first century. In what follows I draw especially on the work of Thomas Sowell and James Flynn. There was a black presence in America from the very beginning of European settlement. Twenty black indentured servants landed in Jamestown twelve years after the founding of the colony. In eighteenth-century Virginia, blacks and whites were as integrated as they are today, and in some ways more so. Blacks and whites commonly attended the same church, and it was not unusual for the minister to be black. The European settlers adapted many aspects of African culture, including agricultural methods, cuisine, and mythology, to the common civilization that the t w o groups were building together. Blacks in both the North and the South in the eighteenth century had, if not an equal place at the table, at least an accepted and valued status in the larger society. The lives of most blacks were not all that different from those of white indentured servants, who served for a term as apprentices and then were free to do as they chose. Blacks were not bound for a lifetime to a particular master. From early on, many blacks in the North had never been slaves or had been freed from slavery. In the big cities of the North, "free persons of c o l o r " were preferred to the Irish as employees and neighbors right up to the early-twentieth century, when it was still possible to see signs at factories and in shop windows reading, "Colored man preferred. No Irish need apply." Though most free blacks in the North were servants and semi-skilled or unskilled

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workers, their numbers included artisans, tradesmen, and skilled workers in the early years. In Boston in i860, blacks had a higher occupational status than the Irish, and hotels in N e w York paid black employees higher wages than they paid the Irish. Eighty-five percent of free black families dwelling in both the North and the South in the 1855—80 period were headed by males. In Philadelphia, male-headed families were more common among free blacks than among any other group. The percentage of families that were headed by males was much lower for the Irish in the nineteenth century than it was for blacks. Racial segregation was not substantial in the cities of the North until well into the twentieth century. In Chicago in 19 10 more than three-quarters of blacks lived in neighborhoods that were mostly white. To give an idea of how different many of the urban free persons of color were from the image of the urban black of today, consider the group of five hundred free blacks in the Washington, D.C., of 1800 and their descendants. They created their own schools, beginning in 1807, which black children attended until they were finally admitted to public schools in 1862.. They also founded the first black high school in 1870. From that time until the middle of the twentieth century, three-quarters of the students in that high school went on to college, above the average for whites even today. In the early 1900s, students at the black high school scored higher on a city-wide achievement test than did students at any white high school in D.C. Once IQ tests began being given, students in that high school scored above the national average. Its graduates include the first black general, the first black cabinet member, the first black federal judge, the first black senator since Reconstruction, and the discoverer of blood plasma. It was not foreordained that the free persons of color would fail to become fully equal citizens in the North. They had a head start 011 the Irish. It was the enslavement of large numbers of blacks in the South and the subsequent migration of large numbers of impoverished and illiterate blacks to the cities of the North beginning in the late-nineteenth century that undid the northern blacks.

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Slavery created conditions for blacks in the South not unlike those for the Irish in Ireland. A crucial fact for both groups is that labor did not produce value for the worker, and so hard work was not initially a cultural value for either group. The work of the slave resulted in gain only for the slave owner, and the work of the Irish resulted in gain only for the absentee English landlord. Even the cottage—or more typically hovel—where the Irishman lived was owned by the landlord, so the Irishman had little inducement to make improvements to the property because they would only redound to the advantage of the owner. An ecological fact about Ireland led in a direct way to still another reason for the traditional Irish dislike of work: the most productive use of the soil in Ireland was for the growing of potatoes, but the crop requires only a couple of weeks of work a year. When the Irish first came to the N e w W o r l d in large numbers in the midnineteenth century, they had no tradition of steady work. M o r e than a century would pass before their reputation as layabouts was put to rest. The end of slavery in the South did not result in economic freedom for the blacks. The conditions of the blacks under slavery were superior in many ways to what they were to become in the post—Civil War period. Although blacks initially enjoyed a measure of political freedom during the Reconstruction period— and indeed many were elected to federal office because former rebels were not allowed to vote or run for office—huge numbers of blacks subsequently were forced into peonage in the form of sharecropping. By the latter part of the nineteenth century, after the imposition of Jim Crow practices of discrimination, economic conditions were poor for the great majority and desperate for many. In an attempt to escape poverty and discrimination in the South, many blacks fled to northern urban centers. The great migration to the North began at the end of the nineteenth century and roughly doubled each decade until 1940. The people who arrived in the North were desperately poor, had few skills and little education, and were thoroughly rural in

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INTELLIGENCE AND HOW TO GET IT

habits and attitudes. They overwhelmed the descendants of the free persons of color, changing the nature of the indigenous black community and bringing considerable social pathology to the cities of the North. If the labor market had been fully open to the new arrivals, the history of blacks in the urban North in the twentieth century might have been a thoroughly positive one. But the labor movement for the most part excluded blacks. Black men were denied entry into unions just as access to high-paying jobs became ever more dependent on holding a union card. Only in a few industries in a few regions, such as the auto industry in Detroit, were blacks allowed into the unions in significant numbers. Elsewhere blacks were relegated to semi-skilled and unskilled jobs, and even for those jobs blacks were the last hired and the first fired. The Irish, who were white (or as author Noel Ignatiev put it, became white), were gradually admitted into unions and rose from the underclass to the lower class and ultimately in great numbers into the middle class. The two other institutions that had a great deal to do with the rise of the Irish were politics—and the patronage that came with it—and the Catholic church, which waged a heroic struggle to educate poor Catholic immigrants. As of the mid-twentieth century, the Irish in Ireland had IQs at about the level of blacks in America. English psychologist H. J. Eysenck attributed this to the genetic consequence of the fact that the intelligent people had fled Ireland to other lands, leaving the dull-witted—and their inferior genes—behind. The gene pool of Ireland must have been more robust than Eysenck thought, however, because the per capita gross domestic product of Ireland is now greater than that of England, and literacy proficiency for children is higher than that of the United Kingdom. (This achievement was no accident. It was the result in part of an intensive education initiative begun in the 1960s. Post—secondary school enrollment increased from 1 t percent in 1965 to 57 percent in 2003.) Despite the dislocating effects of the black migration from the South on both the immigrants and the cities they came to, and

IQ in Black and White

109

despite the near-exclusion of the immigrants from high-paying union labor, economic conditions for the immigrants were far better than they had been in the South. The conditions of the urban poor improved steadily throughout the century, with the exception of the Depression era. A huge spurt in economic conditions came in the 1960s and 1970s (perhaps not coincidentally, the period during which the children who made great gains in school achievement were born). By 1970, black families with a husband and wife who both worked made almost as much money as comparable white families. The size of the black middle class continues to expand. The proportion of blacks who are occupationally in the middle class moved from 10 percent in 1950 to 3 1 percent in 1976 to 52. percent in 2.002.. But already by the 1960s, the fortunes of the black population were bifurcating. The middle class was growing, but large numbers of blacks were remaining mired in deep poverty. The economic divide in the black community has everything to do with the difference that stable marriage makes. The households where a man is present and employed are doing very well. But the roughly two-thirds of black families headed by a woman are doing much less well. For every black man who drops out of school and hence often out of the workforce, there is likely to be a single mother who must fend for herself. Every female-headed family is more likely to produce males who will drop out of school and out of the workforce and out of the marriage pool. And so on, in a vicious cycle.

Caribbean

Cultural

Capital

In addition to the descendants of the northern free blacks and the former slaves, there is a third distinctive group of blacks. It has a very different, and very grisly, past but a much better present and a brighter future. This group is the West Indian immigrants to this country. West Indians constitute less than 1 percent of the population but have produced a vastly disproportionate number

1 10

INTELLIGENCE AND HOW TO GET IT

of eminent black Americans—from Marcus Garvey to Colin Powell. In 1970, second-generation West Indians exceeded Americans in general in median family income, in level of education, and in percentage in the professions. Unlike black immigrants from the South, West Indian immigrants to the big cities of the North behaved like many other groups of foreign immigrants. They took whatever jobs were available, saved their money, started or purchased small businesses, and saw to it that their children were educated even if they had to forgo luxuries or necessities for themselves. They moved into the professions and high-ranking business positions at a far higher rate than did native blacks. On the surface, these accomplishments are particularly remarkable given that the nature of slavery in the West Indies was in every respect more gruesome and inhumane than that of the United States. N o r can the success of West Indians in America be traced to a greater dose of either European genes or European culture. The admixture of European genes to the West Indian pool was far less than it was in the United States. And West Indian culture is much more rooted in African culture than is American black culture. (Sowell recently argued that the culture of the "street" people in the black inner city owes much more to the culture of Northern Ireland and the Scottish borderlands of the eighteenth century, and to the white rednecks who modeled that culture for the blacks in the U.S. South, than to the West Africa of that period.) In Sowell's view, the key to West Indian exceptionalism lies in the economic history of slavery in that part of the N e w World. In the U.S. South, slaves were fed from a central kitchen or had food doled out to them for preparation in their own quarters. In the West Indies, blacks raised their own crops and sold the surplus in the markets. Because of the small number of whites, all of the skilled labor and artisanship as well as much of the entrepreneurship had to come from the black population. The West Indians arrived in this country poor, but they were in a far better position to take advantage of the opportunities in America than were their country cousins from the U.S. South.

IQ in Black and White 122

I must point out that West Indian immigrants are not a random sample of the West Indian population as a whole. The very lowest echelons of West Indian society have not been well represented among the immigrants, who include a much higher proportion of the professional and managerial classes than is characteristic of the West Indian population as a whole. Self-selection, in short, counts for some unknown portion of the success rate of West Indians in this country, and this self-selection undoubtedly includes some unknown degree of genotypic advantage for intelligence. Despite this disproportionate influx of skilled individuals, the occupational and educational success of West Indians tells us something crucial about the role played by racism in the lower occupational achievement of blacks. However severe racism may be, it does not prevent blacks from attaining high levels of achievement if they have good skills and favorable attitudes toward work. (Of course, it helps that in N e w York City and other places where there are large numbers of West Indian blacks, the stereotype of West Indians is that they are reliable and hard working. A lilting Caribbean accent is an asset on the labor market.)

Parenting

Practices

The cultural capital of West Indians is unusually great, whereas that of some native blacks is distinctly lower than that of the majority population. On top of all the demographic disadvantages of American blacks as a whole, many also socialize their children in ways that are less likely to encourage high IQ scores and high academic achievement than do whites of comparable social and economic circumstances. Nothing is more telling than the way that many black parents interact verbally with their children. I pointed out in the previous chapter (on social class) that children of professionals hear about 2,000 words per day and working-class children, both black and white, hear about 1,300. Children born to blacks on welfare, however, hear only about 600 words per day. By the time the child of

1112

INTELLIGENCE AND HOW TO GET IT

professionals is three years old, she has heard 30 million words; the child of welfare blacks has heard 10 million. The vocabulary used by the three-year-old child of professionals in talking to her parents is richer than that of the black welfare mother in talking to her child. Recall from the last chapter the study by anthropologist Shirley Rrice Heath of children in a rural community in the South. During the 1960s and 1970s, she lived with three different types of families for a period of many months and followed their children to school. She studied white middle-class families in which at least one parent was a teacher, white working-class families, and black lower-class families. Many of the respects in which working-class families differed from middle-class families were found to be characteristic of poor black families as well. But many aspects of black socialization for language were quite different from the practice of either class of whites—and even more disadvantageous for preparation for school. The poor black child was born into an extended family that bathed it in communication, both verbal and nonverbal. But the adults did not speak to the child directly—they made no effort to interpret the baby's sounds as words. They did not simplify their language for the child. N o r did they label objects or events or make any attempt to link objects in the here and now with other objects encountered in other contexts. In other words, they did not decontextualize things in such a way that learning in one situation could be carried over into others. Children didn't play with educational toys but with safe household objects instead—spoons, plastic food containers, pot lids. Older children might get electronic and mechanical toys. But they didn't get manipulative toys—blocks, take-apart toys, or puzzles—to play with. N o r did the children get books. The adults read newspapers, mail, calendars, advertising brochures, and the Bible, but there were 110 special reading materials for children other than, sometimes, Sunday-school materials. The adults did not sit their children down and read to them. There was no special bedtime ritual,

IQ in Black and White

113

or even a specified time for going to sleep when the bedtime story might become a fixture. The children were not asked what questions about their environment. They were instead asked for nonspecific comparisons: "What's that like?" (This probably pays off later in an ability to see similarities. Similarities subtests of IQ tests are the ones that blacks do best on.) The children's abilities to link two events together metaphorically produced no advantage for them in school. In fact, those abilities often caused problems because they allowed children to see linkages that the teacher had not intended. By the later grades of elementary school when children are asked to compare and evaluate—and when the skills in detecting similarities would have been useful—the children had fallen too far behind. They did not have the verbal and written comprehension skills that would allow them to put analogies in a form that teachers might accept. In the home, the children were not asked known-answer questions—that is, questions for which the adult knows the answer ( " W h a t color is the elephant, Billy?"). As a consequence the children were not prepared for such questions when they started school. Even the simplest question from the teacher might go unanswered because the child was nonplussed by the form of the question ( " I f the teacher doesn't know this, then I sure d o n ' t . " ) The children did engage in storytelling in the home—if they could gain center stage for long enough. But the stories told were not likely to be impressive in the school context. They typically had no beginning and no ending—just an effort to entertain until the audience lost interest. The children had narrative abilities that exceeded those of white working-class kids and even those of many if not most white middle-class kids. (The narrative skills of blacks are much in evidence in the entertainment industry and among clergymen. There is a saying that the worst black preacher on his worst Sunday is a more effective speaker than the best white preacher on his best Sunday.) In school, children were asked to classify objects with respect to shape, color, or size. But the impoverished black children had

INTELLIGENCE AND HOW TO GET IT

1 14

n o t been t a u g h t to c a t e g o r i z e , so this e x e r c i s e w a s very foreign to them. A n d w h e n they w e r e asked to interpret scenes in b o o k s — which

are

inevitably stylized—they

often

found

it difficult to

relate the scenes to c o n c r e t e o b j e c t s a n d events in the w o r l d . In the late 1 9 8 0 s , H e a t h returned to N o r t h C a r o l i n a to study the children of the children she had studied

more than twenty

y e a r s before. T h e original c o m m u n i t y she h a d visited no longer existed. T h e c l o t h i n g mills w h e r e s o m e o f the parents had w o r k e d had closed, a n d the f a r m s w e r e n o w mechanized. While s o m e o f the c h i l d r e n h a d e s c a p e d to m i d d l e - c l a s s o c c u p a t i o n s in the cities, the p e o p l e H e a t h studied w e r e those w h o lived in a s l u m area in the original t o w n a n d others w h o lived in a l o w - i n c o m e high-rise in A t l a n t a . T h e children were n o w parents, usually having become so at an early a g e . In f a c t , e v e r y single girl H e a t h had studied in the original c o m m u n i t y had had a child d u r i n g her teenage years. T h e n e w m o t h e r s did not h a v e b a b y - t a l k g a m e s w i t h their children and did not label things in the e n v i r o n m e n t f o r them. T h e y did not a s k t h e i r c h i l d r e n t o tell t h e m a b o u t t h e i r d a y . W h e n t h e c h i l d d i d talk, the m o t h e r s o m e t i m e s ridiculed a n y display of k n o w l e d g e . In m a n y c a s e s , the children b e c a m e the c h a r g e of the teenager's m o t h e r . T h e t e e n a g e r r e t u r n e d t o h i g h s c h o o l a n d t h e s o c i a l life there. O n e o f the teenagers H e a t h studied, w h o w a s o n w e l f a r e m o s t of the time, rarely e n g a g e d in m u c h interaction with her children or enlisted t h e m in talk of a n y k i n d , a n d w h e n she d i d , the interaction t y p i c a l l y l a s t e d less t h a n a m i n u t e . H e r w o r l d w a s m u c h less rich linguistically a n d socially t h a n the e x t e n d e d f a m i l y she h a d been b o r n into i n N o r t h C a r o l i n a . H e r l a n g u a g e e x p e r i e n c e w a s limited to passively watching TV or reading movie or TV magazines. T h e p e o p l e she a s s o c i a t e d w i t h w e r e the largely transient w o m e n in the p r o j e c t w h e r e she lived. T a l k o f the f u t u r e f o r these w o m e n w a s o f the i m m e d i a t e f u t u r e o n l y — h o w t o get d o c u m e n t s t o the w e l f a r e o f f i c e or h o w d a y - c a r e rules m i g h t c h a n g e or h o w she could get the children's father to start sending m o n e y again. It is clear f r o m H e a t h ' s r e p o r t that f o r the children of at least

IQ in Black and White s o m e o f the

115

y o u n g parents of the

late

1980s,

their cognitive,

s o c i a l , a n d e m o t i o n a l lives w e r e f a r less rich than their p a r e n t s ' h a d been w h e n g r o w i n g up. M o r e s y s t e m a t i c studies of the h o m e life of a s a m p l e of black families in the

representative

1 9 8 0 s support H e a t h ' s view that

the h o m e e n v i r o n m e n t s o f b l a c k s i n that era a n d n o w c a n b e intellectually impoverished a n d e m o t i o n a l l y harsh. M e r e d i t h Phillips, J e a n n e B r o o k s - G u r m , and their c o l l e a g u e s h a v e l o o k e d in detail at the results of studies m e a s u r i n g aspects of the h o m e e n v i r o n ment of blacks and whites. Their analysis w a s based on t w o data sets.

One came

Longitudinal

from

a

study called

Children

of the N a t i o n a l

Survey of Youth, or C N L S Y . T h e study began

in

1 9 8 6 and covered more than six thousand children born to people w h o w e r e between the ages of fourteen and t w e n t y - t w o in 1 9 7 9 . A wide range of demographic and

home variables w a s studied.

T h e s e c o n d d a t a set c a m e f r o m the m a s s i v e I n f a n t H e a l t h a n d Development Program (IHDP), which examined children born at eight different hospitals w h o had birth w e i g h t s l o w e r than 2.,500 g r a m s (about five a n d a half p o u n d s ) — a figure that is c o n s i d e r e d t o p l a c e t h e m a t risk f o r l o w I Q a s w e l l a s a r a n g e o f p h y s i c a l health p r o b l e m s . In the n e x t c h a p t e r I d i s c u s s the e f f e c t s of an extremely a m b i t i o u s intervention p r o g r a m on the s u b s e q u e n t IQ and a c a d e m i c a c h i e v e m e n t of these children. F o r the time being I c o n s i d e r o n l y t h e 3 1 5 b l a c k a n d w h i t e c h i l d r e n in t h e c o n t r o l g r o u p i n I H D P w h o s e birth w e i g h t w a s b e t w e e n 1 , 0 0 0 g r a m s a n d 2,500 grams. T h e measures that Phillips and

her colleagues e x a m i n e d

are

c o n t a i n e d i n the so-called H O M E scale ( H o m e O b s e r v a t i o n f o r M e a s u r e m e n t o f the E n v i r o n m e n t ) .

Scores on

this m e a s u r e are

based on an i n t e r v i e w e r ' s o b s e r v a t i o n s in the h o m e a n d q u e s t i o n s asked

o f the

mother.

Things studied

include

"learning experi-

ences o u t s i d e the h o m e (trips to m u s e u m s , visits to f r i e n d s , trips to the g r o c e r y store), literary e x p e r i e n c e s w i t h i n the h o m e (child has more than

10 books, mother reads to child, family member

reads newspaper, family receives magazine), cognitively stimulat-

INTELLIGENCE AND HOW TO GET IT

1116

ing activities within the h o m e (materials that i m p r o v e learning of skills such as r e c o g n i t i o n of letters, n u m b e r s , c o l o r s , s h a p e s , sizes), p u n i s h m e n t ( w h e t h e r child w a s s p a n k e d d u r i n g the h o m e visit; maternal

disciplinary

style),

maternal

warmth

(mother

kissed,

c a r e s s e d , o r h u g g e d the c h i l d d u r i n g the visit; m o t h e r p r a i s e d the child's a c c o m p l i s h m e n t s d u r i n g the visit), a n d the physical envir o n m e n t ( w h e t h e r the h o m e is r e a s o n a b l y clean and uncluttered; w h e t h e r the child's play e n v i r o n m e n t is s a f e ) . " D i f f e r e n c e s b e t w e e n b l a c k a n d w h i t e h o m e s i n the t w o s t u d ies w e r e m a r k e d a n d r a n g e d a s h i g h a s t h r e e - f i f t h s o f a s t a n d a r d d e v i a t i o n o n s o m e m e a s u r e s . W i t h i n the black s a m p l e , scores o n the H O M E scale w e r e closely associated with scores o n cognitive v a r i a b l e s . F o r the C N L S Y s t u d y , the v o c a b u l a r y s c o r e f o r five- a n d s i x - y e a r - o l d s w a s e q u i v a l e n t to an additional 4 IQ points w h e n the m o t h e r r e a d t o t h e m d a i l y a s o p p o s e d t o n o t a t all. F o r t h e I H D P s t u d y , IQ scores w e r e 9 points higher w h e n a f a m i l y scored 1 stand a r d d e v i a t i o n a b o v e t h e m e a n 011 all t h e H O M E m e a s u r e s . Hart and described

Risley,

in

in

Chapter

their study of K a n s a s families, which 5,

found

huge

differences

across

I

groups

in h o w parents treated their children in terms of w a r m t h versus p u n i s h m e n t . Recall that the children of professionals received six e n c o u r a g e m e n t s per r e p r i m a n d a n d the children o f w o r k i n g - c l a s s parents received t w o e n c o u r a g e m e n t s per reprimand. T h e children of black w e l f a r e parents received t w o reprimands per encouragem e n t . By the time the child of w h i t e p r o f e s s i o n a l s is three years o l d , she

has heard

5 0 0 , 0 0 0 encouragements and

8 0 , 0 0 0 discourage-

ments. T h e three-year-old black child w h o s e m o t h e r is on w e l f a r e has heard about 7 5 , 0 0 0 encouragements and 2 0 0 , 0 0 0 reprimands. There

is every

reason

to

believe that such

differences could

b e i m p o r t a n t f o r c o g n i t i v e d e v e l o p m e n t . A n d w e k n o w that the discouraging aspects of black parenting are characteristic even of m i d d l e - c l a s s b l a c k p a r e n t s t o a d e g r e e , o r a t least t h e y w e r e i n the 1 9 8 0 s . R e c a l l t h e s t u d y b y E l s i e M o o r e c o m p a r i n g b l a c k a n d interracial children raised by middle-class black or middle-class white parents. T h e I Q s of black a n d interracial children raised by white

IQ in Black and White adoptive parents were

117

13

points higher than those of black and

interracial children raised by black a d o p t i v e parents. We h a v e no idea h o w m u c h o f t h i s d i f f e r e n c e w a s d u e t o t h e h o m e e n v i r o n ment and h o w much

w a s d u e t o the s c h o o l a n d

neighborhood

e n v i r o n m e n t . W e d o k n o w , h o w e v e r , that the h o m e e n v i r o n m e n t o f children raised in the black h o m e s w a s not as likely to p r o m o t e c o g nitive g r o w t h a s m u c h a s t h a t o f c h i l d r e n r a i s e d i n w h i t e h o m e s . M o o r e ' s researchers w e n t into each h o m e and had children w o r k on a b l o c k d e s i g n t a s k , in w h i c h t h e c h i l d l o o k e d at a p i c t u r e a n d tried t o d u p l i c a t e i t u s i n g b l o c k s , w h i l e t h e m o t h e r w a s p r e s e n t . W h i t e m o t h e r s w e r e s u b s t a n t i a l l y m o r e e n c o u r a g i n g a n d less d i s a p p r o v i n g than black m o t h e r s . W h e n the child w a s h a v i n g t r o u b l e w i t h a d e s i g n , the w h i t e a d o p t i v e m o t h e r s t e n d e d t o d i f f u s e t e n s i o n by

joking, grinning, and

laughing. T h e

black

adoptive

mothers

w e r e m o r e likely t o f r o w n a n d s c o w l . T h e w h i t e a d o p t i v e m o t h ers e n c o u r a g e d t h e p r o b l e m - s o l v i n g e f f o r t s o f their c h i l d r e n ( " G e e , that's a n interesting i d e a " o r " Y o u ' r e g o o d a t t h i s " ) . Black m o t h e r s w e r e m o r e likely t o e x p r e s s d i s a p p r o v a l ( " Y o u k n o w t h a t d o e s n ' t l o o k r i g h t " o r " Y o u c o u l d d o b e t t e r t h a n this i f y o u r e a l l y t r i e d " ) . T h e white m o t h e r s also p r o v i d e d help to their children in w a y s m o r e likely t o p r o m o t e l e a r n i n g , s u c h a s s u g g e s t i o n s t h a t t h e c h i l d c o u l d use t o e x p l o r e f o r himself h o w t o w o r k o n the designs ( " W h y d o n ' t y o u w o r k on it o n e section at a t i m e ? " ) . Black m o t h e r s w e r e likely t o g i v e s p e c i f i c i n s t r u c t i o n s , w h i c h left n o o p p o r t u n i t y f o r t h e c h i l d t o discover h o w t o c o m p l e t e the task himself ( " T h a t will w o r k , but y o u h a v e t o t u r n i t a r o u n d like t h i s , " a n d then s h o w s t h e c h i l d t h e appropriate maneuver). T h e white mothers' attitude w a s essentially, "It's o k a y to be w r o n g if you're trying." T h e black mothers w e r e m o r e likely t o d i s p l a y e x a s p e r a t i o n a n d l a c k o f c o n f i d e n c e . I w a n t to stress t w o p o i n t s c o n c e r n i n g this e v i d e n c e a b o u t the behavior o f black and white mothers. First, w e d o not k n o w h o w m u c h it w a s this b e h a v i o r that held b a c k the c h i l d ' s intellectual development and how much it was other environmental factors such as n e i g h b o r h o o d , peers, or schools. Second, it is unlikely that such m a r k e d differences w o u l d be f o u n d b e t w e e n black a n d w h i t e

1 18

INTELLIGENCE A N D HOW TO GET IT

middle-class mothers today. The study is now almost twentyfive years old, and second-generation middle-class parents likely behave differently from first-generation middle-class parents. Certainly we would expect the second-generation middle-class mothers to behave in ways that would more likely promote exploration and growth. The conclusions of the previous chapter and the present one dovetail. Genes account for none of the difference in IQ between blacks and whites; measurable environmental factors plausibly account for all of it. Lower-class blacks and lower-class whites suffer from many of the same disadvantages, but blacks, especially the black working class and underclass, suffer from racial prejudice that blocks their occupational trajectories. Some aspects of black culture—at every social-class level—are less likely to promote cognitive performance compared with white culture. The neighborhoods and schools available to all but middle-class blacks both compound the deleterious effects of that culture and make movement out of it difficult. And even for middle-class blacks, there are adolescent male subcultures that are anti-achievement. These subcultures encourage the belief that athletic skill, a talent for entertainment, and street smarts can substitute for academic skills. I do not doubt that in the normal course of events, slow progress will occur in the socioeconomic and intellectual aspects of black life. Crime rates and drug usage rates have been coming down steadily over the last few decades (though there has been an increase in violent crimes since 2.005). Moreover, black entry into the middle class, and improvement in black IQ and academic achievement scores, continue to increase. In the next chapter you will see whether anything can be done to hasten the movement of poor blacks into the ranks of the working class, and of working-class blacks into the ranks of the middle class.

CHAPTER

SEVEN

M i n d the G a p Compensatory education has been tried, and it apparently has failed. — A r t h u r Jensen ( 1 9 6 9 ) There is no evidence that school reform can substantially reduce the extent of cognitive inequality as measured by — C h r i s t o p h e r Jencks a n d o t h e r s (1972.)

lability J tests.

There is no reason to believe that raising intelligence significantly and permanently is a current policy option, no matter how much money we are willing to spend. — C h a r l e s M u r r a y (2.007)

I N 2 0 0 2 THE U.S. C O N G R E S S

passed

the No C h i l d

Left

Behind

Act,

w h i c h m a n d a t e d that A m e r i c a n s c h o o l s eliminate the g a p b e t w e e n the s o c i a l c l a s s e s a n d

between minority groups and whites by

2 0 1 4 . I don't k n o w if most members of C o n g r e s s actually believed that such a c c o m p l i s h m e n t s are possible. But if s o , they are deeply i g n o r a n t o f the

forces that operate to

produce high a c a d e m i c

achievement. Intellectual c a p i t a l i s the result o f s t i m u l a t i o n a n d s u p p o r t f o r e x p l o r a t i o n a n d a c h i e v e m e n t i n the h o m e , t h e n e i g h b o r h o o d , a n d the s c h o o l s . T o t h i n k t h a t this c a n b e c h a n g e d b y m a n d a t e — o p e r a t i n g o n l y t h r o u g h the s c h o o l s — i s p r e p o s t e r o u s .

M o r e o v e r , the

s c h o o l s a t t e n d e d b y m i n o r i t i e s a n d the p o o r a r e w a n t i n g i n w a y s that c a n n o t be drastically i m p r o v e d overnight. T h e p r o b l e m s include q u a l i t y o f t e a c h e r s w i l l i n g t o w o r k i n these less r e w a r d i n g s c h o o l s , the c a l i b e r o f s c h o o l m a n a g e m e n t , the d i s r u p t i v e n e s s p r o d u c e d b y high levels o f s t u d e n t t u r n o v e r , a n d the n a t u r e o f the s c h o o l s ' clientele, w h o s e h o m e s a n d n e i g h b o r h o o d s m a k e i t u n l i k e l y t h a t t h e y will b e e n c o u r a g e d t o w a r d high a c a d e m i c a c h i e v e m e n t . 1 19

1120

INTELLIGENCE A N D H O W TO GET IT

It should be clear from the previous chapter that there is no theoretical limit on the degree to which the achievement gap between blacks and whites can ultimately be closed. Though there is far less evidence on the native intellectual ability of the extremely broad and diverse group of cultures labeled as "Hispanic," I see no reason why the gap cannot ultimately be bridged there as well. On the other hand, it should be clear that unlike the black/white and Hispanic/white gaps in achievement and IQ, the social-class gap is never going to be closed. This is true, if for no other reason, because the well-off are always going to find ways to get a better education for their children and are always going to find ways to be ahead in terms of parenting skills and are always going to be able to provide superior neighborhood environments. In addition, there is always going to be at least some difference in the gene pools of the lower class and the middle class. Recall from Chapter i that within a given family the sibling with a substantially higher IQ achieves much higher socioeconomic status (SES) than less favored brothers and sisters. And since the higher IQ is attained in part by virtue of a better luck of the draw from the gene pool of the parents, higher SES is always going to be in part a result of better genes for intelligence. So higher-SES people are going to pass along better prospects for intelligence to their offspring by virtue of having, on average, better genes and by offering better environmental advantages to their offspring. But these considerations should not be cause for pessimism about the degree to which the intellectual lot of lower-SES people can be improved. Recall from Chapter z (on heredity) that the effect of an upper-middle class upbringing on children born to lower-SES parents is to raise the IQ by i 2. to 18 points. The theoretical ceiling for improvement of lower-SES intellectual capital is very high indeed. But how much improvement can we realistically hope to produce for lower-SES individuals and for currently disadvantaged minorities?

Mind the

Early

12 5

Gap

Childhood

Education

W h e n 1 tell p e o p l e t h a t I a m w r i t i n g a h o o k o n t h e m o d i f i a b i l i t y o f i n t e l l i g e n c e , t h e y s o m e t i m e s tell m e , s o a s t o e n c o u r a g e m e t o avoid wasting my time, that H e a d Start does not w o r k . For m a n y p e o p l e their belief a b o u t o n e p a r t i c u l a r p r o g r a m settles the m a t t e r of whether intelligence can be m a n i p u l a t e d . H e a d Start is a c o m p e n s a t o r y p r o g r a m initially a i m e d p r i m a r ily a t i m p r o v i n g t h e h e a l t h a n d w e l f a r e o f p o o r c h i l d r e n t h r e e a n d f o u r years old. S o m e of the f o u n d e r s h o p e d that it w o u l d also lead to i m p r o v e m e n t s in the c h i l d r e n ' s intelligence, s c h o o l p e r f o r m a n c e , a n d s u b s e q u e n t s u c c e s s i n life. H e a d S t a r t s e s s i o n s r u n f o r a h a l f - d a y five days a w e e k , typically for thirty-four w e e k s , but only a small portion of each session specifically targets cognitive concerns. Is H e a d Start a failure? It d e p e n d s on y o u r perspective. With respect to physical health, H e a d Start has been a r e s o u n d i n g success. It results in m o r t a l i t y rates f o r c h i l d r e n that a r e 3 3 to 75 percent l o w e r than f o r c o m p a r a b l e children not in the p r o g r a m . I t h a s d r i v e n m o r t a l i t y r a t e s d o w n , i n f a c t , t o a level n o t s u b s t a n tially d i f f e r e n t f r o m t h o s e f o r children in g e n e r a l . In earlier d a y s . H e a d Start w a s associated with a gain of a b o u t . 3 5 SD on cognitive tests, or a b o u t 5 IQ points, w h e n the child finished the p r o g r a m a t a g e f i v e , a n d m o r e recent studies s h o w e d t h a t t h e r e i s still a . 1 0 t o . 2 0 S D e f f e c t o n s o m e I Q a n d a c h i e v e ment variables at age six or seven. T h e s e f a d e into nothingness by late e l e m e n t a r y s c h o o l . R e c e n t r e p o r t s s h o w l o w e r e f f e c t sizes a t a g e f i v e — 0 1 1 t h e o r d e r o f .2.5 S D . B u t i t i s d i f f i c u l t t h e s e d a y s t o find true control g r o u p s f o r p r e - k i n d e r g a r t e n interventions b e c a u s e the majority of even p o o r m i n o r i t y children receive s o m e kind of pre-kindergarten care. As a result, effects are c o m p a r e d , not to notreatment controls, but to c o n t r o l g r o u p s in w h i c h typically half of the children h a v e s o m e d a y care. There are shockingly

few evaluations on

the

long-term aca-

d e m i c e f f e c t s o f H e a d S t a r t . W h a t little t h e r e i s i n d i c a t e s a s l i g h t effect of H e a d Start on c o m p l e t i o n of high s c h o o l , w h i c h is a b o u t

INTELLIGENCE AND HOW TO GET IT

1122

z to

5

percent greater than

f o r c o n t r o l s , a n d a small effect as

well on l i k e l i h o o d of a t t e n d a n c e in college, w h i c h is a b o u t 3 to 6 percent greater than for controls. T h e cost of H e a d Start is about $ 7 , 0 0 0 per child, so w h e t h e r the p r o g r a m is w o r t h the gain f r o m an intellectual a n d a c a d e m i c standpoint is an open question. E a r l y H e a d Start, w h i c h begins at birth a n d continues to a g e t h r e e , h a s p r o v e d t o b e n o m o r e successfLil t h a n H e a d S t a r t i n i m p r o v i n g educational o u t c o m e s . Services include child development, child care, h o m e visiting, parenting education, and family support services. Individual p r o g r a m s have been given substantial l a t i t u d e a b o u t w h i c h s e r v i c e s t o e m p h a s i z e . E f f e c t s i z e s 011 a r a n g e o f v a r i a b l e s f r o m the p u r e l y c o g n i t i v e t o the e m o t i o n a l a n d social are in

the r a n g e of . 1 0 to . 3 0 S D — s l i g h t l y higher f o r minority

children

than

for white children.

Even

the

best versions of the

p r o g r a m p r o d u c e d IQ g a i n s of less than 4 p o i n t s in the s h o r t term (though

vocabulary

scores

increased

by

.40 SD).

The program

is expensive, and it is not clear w h e t h e r long-term gains (which a p p a r e n t l y will not be m e a s u r e d ) w o u l d justify the cost. But there are

m o r e a m b i t i o u s p r o g r a m s than

H e a d Start, and

s o m e of t h e m h a v e m u c h bigger a n d m o r e lasting results. A r e v i e w of a b o u t a d o z e n of the better small-scale p r e s c h o o l a n d kindergarten p r o g r a m s f o c u s i n g o n b l a c k c h i l d r e n s h o w e d t h a t t h e y l e a d t o big gains in I Q — o f as m u c h as . 7 0 SD or even m o r e at age five. T h e y a l s o result in s i g n i f i c a n t a c h i e v e m e n t g a i n s in the first f e w g r a d e s of elementary school, but these gains generally fade, often completely. Fading is to be expected if high-quality environments are not m a i n t a i n e d . O n l y if children's brains are like clay w o u l d we e x p e c t them to remain in g o o d shape years after they were f o r m e d . If children's brains are like muscles, h o w e v e r , then w e w o u l d e x p e c t exercise, in the f o r m of stimulating e n v i r o n m e n t s and activities, to be necessary to m a i n t a i n g o o d p e r f o r m a n c e . I f a v o r the muscle view, and so do the data. As

it turns

out,

several early childhood

education

programs

actually do produce large immediate gains in IQ, as well as longterm gains in

IQ or academic achievement, or both.

Let's look

Mind the

12 5

Gap

at three of the m o r e e f f e c t i v e p r o g r a m s that r a n d o m l y a s s i g n e d children to treated versus untreated conditions and that f o l l o w e d the children until late a d o l e s c e n c e or a d u l t h o o d . The

Perry

Preschool

Program

w a s carried

out

in

Ypsilanti,

Michigan, between 1 9 6 2 and 1 9 6 7 by L a w r e n c e Schweinhart and David Weikart. It w a s administered to fifty-eight black children living in poverty w h o s e m o t h e r s had I Q s between 75 a n d 85 on the S t a n f o r d - B i n e t I Q test. C h i l d r e n e n t e r e d the p r o g r a m a t a g e f o u r in the first y e a r of o p e r a t i o n a n d at a g e three in the r e m a i n i n g f o u r years. With the e x c e p t i o n of the first g r o u p , children spent t w o years in the p r o g r a m . T h e Perry treatment consisted of daily m o r n i n g sessions in a classr o o m l a s t i n g t w o a n d a half h o u r s f o r t h i r t y w e e k s e a c h y e a r a n d focused on activities that w o u l d foster cognitive g r o w t h a n d social development. T h e average child-teacher ratio w a s 6 to 1, which is extremely l o w , and staff were very well trained in early childhood d e v e l o p m e n t a n d e d u c a t i o n . O n c e a w e e k , the teacher w o u l d a l s o visit e a c h c h i l d ' s h o m e f o r n i n e t y m i n u t e s t o e n c o u r a g e t h e m o t h e r to b e c o m e involved in the e d u c a t i o n a l process. T h e fifty-eight children comprised the treatment g r o u p , and sixty-five w e r e in a control g r o u p . W h e n children c o m p l e t e d the p r o g r a m , they entered s c h o o l i n the d i s a d v a n t a g e d n e i g h b o r h o o d s w h e r e t h e y l i v e d . T h e m e a n IQ of the children in the c o n t r o l g r o u p at the end of the p r o g r a m , a t a g e f i v e , w a s 8 3 . T h e m e a n I Q o f the t r e a t m e n t g r o u p w a s 9 5 . T h e I Q o f the treatment children d r o p p e d progressively o v e r the y e a r s o f g r a d e s c h o o l until i t w a s the s a m e a t a g e ten a s t h e c o n t r o l m e a n , 8 5 . The given

IQ the

results are d i s a p p o i n t i n g , circumstances

of

home,

though

scarcely surprising

neighborhood,

and

school

after t e r m i n a t i o n of the p r o g r a m . W h a t is s u r p r i s i n g is that the academic gains and subsequent economic and social gains were enormous. These are summarized in Figure 7 . 1 A on page About a

third

of the c o n t r o l - g r o u p c h i l d r e n

special education classes at s o m e point, versus

were

128.

assigned

to

1 3 percent o f the

treatment g r o u p . At age fourteen, only 14 percent of the control

INTELLIGENCE AND HOW TO GET IT

1124

g r o u p tested a b o v e the i o t h percentile o n the C a l i f o r n i a Achievement Test, compared

with

a l m o s t half of the treatment g r o u p .

E f f e c t sizes f o r reading, m a t h , a n d l a n g u a g e a c h i e v e m e n t scores r a n g e d f r o m 0 . 5 0 t o 0 . 7 5 S D . F o r t y - t h r e e percent o f the control g r o u p m a n a g e d t o g r a d u a t e f r o m high s c h o o l , c o m p a r e d with 6 5 percent o f the treatment g r o u p . H i g h school g r a d e s w e r e . 5 7 S D higher f o r the treatment g r o u p than f o r the control g r o u p . At age t w e n t y - s e v e n , o n l y a b o u t 6 percent of the c o n t r o l g r o u p earned a s m u c h a s $ 2 , 0 0 0 per m o n t h v e r s u s 2 8 percent o f the treatment group.

Eleven

percent

home, whereas 33

o f the

control

group

owned

their o w n

percent o f the t r e a t m e n t g r o u p o w n e d their

o w n h o m e . A b o u t 2 0 percent o f the control g r o u p had m a n a g e d n e v e r t o b e o n w e l f a r e , c o m p a r e d w i t h 4 0 p e r c e n t o f the t r e a t m e n t g r o u p . Eight percent o f the c o n t r o l - g r o u p w o m e n a n d 4 0 percent o f the t r e a t m e n t - g r o u p w o m e n w e r e m a r r i e d . B y the a g e o f f o r t y , 55 percent of the c o n t r o l s had five or m o r e arrests; 36 percent of the t r e a t m e n t g r o u p had five o r m o r e arrests. T h e s e results h a v e tremendous social and e c o n o m i c implications. T h e Perry p r o g r a m is by no means unique in showing fading IQ gains

for

intervention

ment a d v a n t a g e s later in

groups combined

with

big achieve-

life. T h e s e a d v a n t a g e s include l o w e r

percentage retained in grade, l o w e r percentage in special education, and higher percentage graduating from

high school. T h e

f a c t that g a i n s in a c a d e m i c a n d life a c h i e v e m e n t can be so great e v e n t h o u g h I Q g a i n s h a d c o m p l e t e l y d i s s i p a t e d h a s led m a n y to suspect that the a c h i e v e m e n t gains are attained not through increased intelligence per se but rather through temperamental or m o t i v a t i o n a l c h a n g e s that resulted f r o m the intervention and that persisted even w h e n the I Q g a i n s w e r e n o longer s u p p o r t e d by the e n v i r o n m e n t . A n intervention even m o r e a m b i t i o u s than the Perry p r o g r a m w a s started by researchers in M i l w a u k e e . R i c k H e b e r , the prog r a m ' s initiator, d i s c o v e r e d that o n e p a r t i c u l a r area of the city, w h i c h had 3 percent of the p o p u l a t i o n , a c c o u n t e d for 33 percent of the mentally retarded children in the district. He decided to

Mind the

Gap

12 5

c o n c e n t r a t e his r e s o u r c e s on that section of the city. A l l of the children recruited f o r the s t u d y w e r e A f r i c a n A m e r i c a n s a t high risk f o r m e n t a l r e t a r d a t i o n b e c a u s e t h e i r m o t h e r s w e r e p o o r a n d h a d I Q s o f 7 5 o r less. T h e c h i l d r e n w e r e r a n d o m l y a s s i g n e d e i t h e r to a control g r o u p (eighteen children) or to an intervention g r o u p (seventeen children), w h i c h

was an

intensive day-care p r o g r a m

l a s t i n g f r o m t h e t i m e t h e c h i l d r e n w e r e less t h a n s i x m o n t h s o l d until they e n r o l l e d in first g r a d e . T h e intention o f the M i l w a u k e e Project w a s t o g i v e children the equivalent of a middle-class environment. T h e p r o g r a m focused on developing their l a n g u a g e skills a n d cognitive capacities. P a r a p r o f e s sionals frequently interacted with the children in an e n j o y a b l e w a y , using the best d e v e l o p m e n t a l p r o g r a m s a n d e d u c a t i o n a l t o y s k n o w n at the time. Sessions lasted seven h o u r s each d a y , f o r five d a y s each w e e k . T h e p r o g r a m p r o v i d e d the children with g o o d f o o d a n d highquality medical and dental care and offered training in h o m e m a k i n g a n d child c a r e t o the m o t h e r s . T h e t r e a t m e n t g r o u p w a s c o m p a r e d not only to the control g r o u p but a l s o to a low-risk c o m p a r i s o n g r o u p of children

born

to mothers of average to above-average

intelligence ( 1 0 8 o n the W e c h s l e r A d u l t Intelligence Scale). A t the a g e o f thirty m o n t h s , the c o n t r o l - g r o u p children h a d a n a v e r a g e I Q o f 9 4 o n the S t a n f o r d - B i n e t test, c o m p a r e d t o 1 2 4 f o r t h e t r e a t m e n t g r o u p children. T h e treatment g r o u p actually scored higher than children born to m o t h e r s with a v e r a g e or a b o v e - a v e r a g e IQs. T h o s e children scored 1 1 3 . By age five, the control g r o u p scored 83 on the W e c h s l e r P r e s c h o o l a n d P r i m a r y S c a l e o f I n t e l l i g e n c e , c o m p a r e d t o 1 1 0 f o r the t r e a t m e n t g r o u p , w h i c h w a s still h i g h e r t h a n t h e I Q score o f i o r for the low-risk c o m p a r i s o n g r o u p . At t e r m i n a t i o n of the p r o g r a m at a g e s e v e n , the a v e r a g e treatm e n t - g r o u p I Q w a s still 2 2 p o i n t s h i g h e r t h a n t h e a v e r a g e f o r t h e c o n t r o l g r o u p . ( N o t e t h a t this g i v e s a n e v e n h i g h e r u p p e r b o u n d f o r the d i f f e r e n c e b e t w e e n t y p i c a l l o w e r - S E S r e a r i n g s t r a t e g i e s a n d s u p e rior strategies.) F o r g r a d e school the M i l w a u k e e children, unlike the Perry children, w e r e put into r e a s o n a b l y high-quality s c h o o l s — a l l rated a t o r a b o v e the n a t i o n a l a v e r a g e f o r s c o r e s o n a c h i e v e m e n t

INTELLIGENCE A N D HOW TO GET IT

1126

tests. T h i s e n a b l e d c h i l d r e n in the treated g r o u p to m a i n t a i n their I Q g a i n s . N i n e y e a r s a f t e r the p r o g r a m w a s o v e r , w h e n the child r e n w e r e a d o l e s c e n t s , the c o n t r o l - g r o u p children s c o r e d 9 1 o n the W e c h s l e r Intelligence Scale f o r C h i l d r e n a n d the t r e a t m e n t - g r o u p children scored

TOT—on par with the 97 IQ f o r the c o m p a r i s o n

g r o u p born to mothers with average or higher IQs. Achievement scores for grades

1

t h r o u g h 4 f o r the treatment

g r o u p w e r e h i g h e r t h a n t h o s e f o r the c o n t r o l g r o u p , a n d the difference w a s great in standard deviation terms—around .75. The n u m b e r of children w a s l o w , h o w e v e r , a n d there is a

10 percent

p r o b a b i l i t y t h a t a d i f f e r e n c e t h a t b i g coLild h a v e b e e n o b t a i n e d b y c h a n c e ( t h o u g h t h e r e i s o n l y o n e c h a n c e i n t w e n t y f o r a reliable difference specifically in f a v o r of the intervention g r o u p , as o p p o s e d to a difference in f a v o r of either group). A

yet

more

intensive

intervention

was

attempted

by

Craig

R a m e y , F r a n c e s C a m p b e l l , a n d their colleagues in a project called the A b e c e d a r i a n P r o g r a m . A l m o s t all o f the TIT c h i l d r e n i n v o l v e d i n the p r o g r a m , w h o w e r e b o r n

between

1972. and

1 9 7 7 , were

A f r i c a n A m e r i c a n . T h e children w e r e c o n s i d e r e d a s being a t high risk of r e t a r d a t i o n in light of their m o t h e r ' s I Q , w h i c h a v e r a g e d 8 5 , a n d m o t h e r ' s e d u c a t i o n , w h i c h a v e r a g e d ten y e a r s , i n a d d i t i o n t o o t h e r risk f a c t o r s s u c h a s l o w f a m i l y i n c o m e , a b s e n c e o f f a t h e r , p o o r social o r f a m i l y s u p p o r t f o r the m o t h e r , p o o r a c a d e m i c perf o r m a n c e of siblings, e m p l o y m e n t of parents in

unskilled labor,

and reliance on public agencies for support. Abecedarian w a s a full-day intervention that began before children were six months o l d a n d lasted all y e a r - r o u n d . T h e i n f a n t - t e a c h e r ratio w a s 3 to 1 at first a n d i n c r e a s e d to a c h i l d - t e a c h e r r a t i o of 6 to 1 as the program

progressed. T h e intervention program continued

kindergarten age.

up to

D a t a w e r e collected on the participants regu-

larly u p until a g e t w e n t y - o n e . T h e p r o g r a m included four g r o u p s of a b o u t twenty-five children each. O n e g r o u p w a s assigned to the infant-kindergarten intervention a n d a l s o to a s c h o o l - a g e intervention. T h e latter intervention p r o v i d e d , f o r the first three elementary school g r a d e s , a

home-

Mind the

12 5

Gap

school teacher w h o met w i t h the p a r e n t s a n d s h o w e d them h o w to s u p p l e m e n t the e d u c a t i o n a l activities at h o m e .

Parents were

e n c o u r a g e d to w o r k with the child f o r at least fifteen minutes a d a y . T h i s h o m e - s c h o o l t e a c h e r w a s a l s o a link b e t w e e n the s c h o o l teachers a n d the f a m i l y . She met w i t h teachers a n d f a m i l i e s o n c e every t w o w e e k s . She a l s o helped the f a m i l y with

finding jobs,

dealing with social service agencies, and taking the children to doctor appointments. O n e g r o u p of children w a s assigned only to the preschool intervention, a n d o n e g r o u p o n l y t o the s c h o o l - a g e intervention. T h e fourth g r o u p w a s assigned to neither intervention. At age three, children w h o had no preschool had an average I Q o f 8 4 ; children w h o received the p r e s c h o o l i n t e r v e n t i o n h a d an a v e r a g e IQ of 1 0 1 . At termination of the intervention, c o n t r o l children

had an average IQ of 94; preschool

intervention chil-

dren, an average of 1 0 1 . T h e n , instead of attending poor-quality i n n e r - c i t y s c h o o l s , all c h i l d r e n w e n t t o s c h o o l s w h e r e m o s t o f t h e children w e r e reasonably well-off white kids. At age twelve, only 1 3 percent o f c h i l d r e n e x p o s e d t o the i n t e r v e n t i o n h a d I Q s o f less than 8 5 , c o m p a r e d to 44 percent of the control children. Even at age t w e n t y - o n e , those w h o had the p r e s c h o o l intervention had an a v e r a g e I Q 4 . 5 p o i n t s higher than the a v e r a g e f o r t h o s e w h o had been i n the c o n t r o l g r o u p . T h e c h i l d r e n w h o s e m o t h e r s h a d the l o w e s t I Q s (less t h a n 7 0 ) b e n e f i t e d t h e m o s t f r o m t h e p r o g r a m . T h e r e is no e v i d e n c e that the s c h o o l - a g e t r e a t m e n t a d d e d a n y thing in the w a y of IQ to the preschool treatment, nor did the s c h o o l - a g e t r e a t m e n t b y itself a c c o m p l i s h m u c h . T h i s s t u d y i s o n e o f m a n y p r o m p t i n g pessimism a b o u t the effects o f h o m e v i s i t s — unless they are very a m b i t i o u s in their scope. By the time the subjects in the study r e a c h e d the a g e of t w e n t y o n e , it w a s clear that the A b e c e d a r i a n p r e s c h o o l intervention h a d had a major influence on m a n y educational o u t c o m e s , summarized in Figure 7 . I . B . A l m o s t half of those in the control g r o u p h a d been assigned to special e d u c a t i o n classes at s o m e point in their e d u c a tional career, versus f e w e r than a fourth of those in the intervention g r o u p . O v e r half of the control g r o u p had repeated a g r a d e , w h e r e a s

1128

INTELLIGENCE A N D H O W T O GET I T

Figure 7.1. Academic, economicy and social outcomes for the Perry Preschool and Abecedarian programs. (A) Data from the Perry program collected when the individuals were twenty-seven years old. > roth percentile achievement, children who scored above the lowest to percent on the California Achievement Test (1970) at age fourteen; HS Gradpercentage of children who graduated from high school on time. (B) Data from the Abecedarian Program collected when the individuals were twenty-one years old (Carolina Abecedarian Project and the Carolina Approach to Responsive Education, 1972.—92.). Light bars, intervention group; dark bars, control group. From Knudsen, Heckman, Cameron, and Shonkoff (2006).

30 percent of the intervention g r o u p repeated a g r a d e . At age fifteen, the r e a d i n g scores o f the intervention g r o u p w e r e 1 . 4 0 S D s higher than those of the c o n t r o l g r o u p , a n d the m a t h scores w e r e . 8 6 S D higher than those o f the c o n t r o l g r o u p . B y a g e t w e n t y - o n e , the intervention g r o u p w a s t w o g r a d e - y e a r s a h e a d o f the control g r o u p in reading scores and m o r e than a year ahead in mathematics scores. H a l f of the control g r o u p had g r a d u a t e d f r o m high school, versus t w o - t h i r d s o f the intervention g r o u p , a n d

1 2 p e r c e n t o f the

control g r o u p had attended a f o u r - y e a r college, versus a third of the i n t e r v e n t i o n g r o u p . A t a g e t w e n t y - o n e , f e w e r t h a n 4 0 p e r c e n t o f the control g r o u p w e r e either in a skilled j o b or in higher education, c o m p a r e d w i t h t w o - t h i r d s o f the i n t e r v e n t i o n g r o u p . T h e Abecedarian effects reported are probably underestimates of the actual e f f e c t s b e c a u s e the c o n t r o l - g r o u p children received pre-kindergarten care of some kind.

Mind the There

12 5

Gap have

Abecedarian

been

several

intervention.

replications of at One

is important

least

part of the

because

it refutes

the c o n t e n t i o n by H e r r n s t e i n a n d M u r r a y that the results of the Abecedarian

study

were

at age one.

found

are suspect since substantial Herrnstein

and

Murray

IQ

differences

believed

such

d i f f e r e n c e s c o u l d n o t b e d u e t o the p r o g r a m a t such a n e a r l y a g e and therefore were indicative not of p r o g r a m effectiveness but of a failure of r a n d o m assignment to produce equivalence of control and intervention g r o u p s at the outset. Project C a r e , using methods essentially

like t h o s e of A b e c e d a r i a n , started

with children

assigned to intervention versus control g r o u p s w h o had identical scores o n the B a y l e y M e n t a l D e v e l o p m e n t I n d e x a t six m o n t h s . B y a g e o n e the s c o r e s f o r the t w o g r o u p s d i f f e r e d b y 1 1 p o i n t s . S o A b e c e d a r i a n has effects o n the I Q o f even very y o u n g c h i l d r e n . Another

replication

of Abecedarian

is

particularly

important

because it s h o w s that the p r o g r a m can be used to b o o s t the IQ of c h i l d r e n a t risk o f m e n t a l r e t a r d a t i o n o w i n g t o p r e m a t u r i t y a n d l o w birth w e i g h t — 2 , 0 0 1 t o 2 , 5 0 0 g r a m s . T w o - t h i r d s o f the i n f a n t s i n the s t u d y w e r e b l a c k o r H i s p a n i c . A b o u t 4 0 p e r c e n t o f the m o t h ers had not g r a d u a t e d f r o m high s c h o o l , a n d o n l y a b o u t 1 3 percent had completed college. T h e p r o g r a m w a s different from Abecedarian i n t h a t r a t h e r t h a n s t a r t i n g s h o r t l y a f t e r b i r t h , i t b e g a n a t a g e o n e , a n d c o n t i n u e d o n l y until a g e t h r e e . A t t h e e n d o f t h e i n t e r v e n t i o n a t a g e t h r e e , I Q s o f t h e i n t e r v e n t i o n g r o u p a v e r a g e d 9.2. t o 1 2 . 5 p o i n t s h i g h e r t h a n c o n t r o l I Q s , d e p e n d i n g o n t h e test u s e d . T w o y e a r s a f t e r the e n d o f the i n t e r v e n t i o n , I Q s o f the i n t e r v e n tion g r o u p w e r e 2 . 5 t o 5.4 p o i n t s h i g h e r , d e p e n d i n g o n the test used (the l o w e r e s t i m a t e w a s n o t statistically s i g n i f i c a n t ) . A t a g e e i g h t , t h e r e w e r e still d e t e c t a b l e e f f e c t s o f t h e i n t e r v e n t i o n , w i t h intervention-group

IQs

ranging from

d e p e n d i n g o n t h e test u s e d .

3.6

to

5.4

points higher,

Even at age eighteen, there w a s a

detectable difference in IQ of 3.8 to 5.3

points between youth

w h o had been i n the intervention p r o g r a m a n d those w h o had not. Achievement differences were not impressive at any point. IQ gains for the intervention g r o u p w e r e m u c h larger f o r the

INTELLIGENCE AND HOW TO GET IT

1130

c h i l d r e n w h o s t a y e d in the p r o g r a m the longest. But this k i n d of a n a l y s i s — s h o w i n g that participants w h o stayed longest benefited most—invites

a

self-selection

bias,

which

was

not

completely

c o m p e n s a t e d f o r by control p r o c e d u r e s used by the investigators. A n d it should be noted that treatment effects were not significant b e y o n d a g e t h r e e f o r i n f a n t s w h o w e i g h e d e x t r e m e l y little a t b i r t h (less t h a n 2 , 0 0 1 g r a m s ) . A particularly i m p o r t a n t fact is that early c h i l d h o o d intervention

programs

white children

benefit

black

and

Hispanic children

m o r e than

( w h o a l r e a d y h a v e m o r e o f the a d v a n t a g e s c o n -

ferred by the interventions, on average), and benefit p o o r children more than middle-class children. In short, early childhood

intervention

for disadvantaged

and

minority children w o r k s — w h e n it is strenuous a n d well conducted. M a n y d i f f e r e n t p r o g r a m s get high g a i n s in IQ by the time they end. T h e s e gains generally f a d e over the course of elementary school, b u t t h e r e i s s o m e e v i d e n c e t h a t t h i s i s less t r u e i f c h i l d r e n a r e p l a c e d in high-quality elementary schools. M u c h m o r e i m p o r t a n t are the achievement gains that are possible: l o w e r percentage of children a s s i g n e d t o s p e c i a l e d u c a t i o n , less g r a d e r e p e t i t i o n , h i g h e r a c h i e v e m e n t 011 s t a n d a r d i z e d t e s t s , b e t t e r r a t e s o f h i g h s c h o o l c o m p l e t i o n a n d c o l l e g e a t t e n d a n c e , less d e l i n q u e n c y , h i g h e r i n c o m e s , a n d less d e p e n d e n c e on w e l f a r e . A n d these c h a n g e s can be very large. T h e r e has not been m u c h research on the effectiveness of homevisitation

programs

having

the

intent

of

improving

parenting

p r a c t i c e s . S o m e r e a s o n a b l y a m b i t i o u s p a r e n t i n g i n t e r v e n t i o n s led to improvements in mothers' behaviors as well as children's emotional and cognitive behaviors. T h e key to success appears to be coaching parents on specific behaviors. One

particularly

effective

intervention

indicates

that

such

programs might have great value. This w a s conducted by Susan L a n d r y a n d her c o w o r k e r s . T h e y w e n t into the h o m e s of mostly lower-income, black and Hispanic mothers of one- to two-yearo l d i n f a n t s a n d p r o v i d e d ten t o t w e n t y i V i - h o u r s e s s i o n s s h o w i n g the m o t h e r s beneficial patterns of response to their infants. T h e y

12 5

Mind the Gap

w o r k e d o n t e a c h i n g m o t h e r s h o w t o interpret the intent o f their child's positive and negative signals, h o w to r e s p o n d to the child's b e h a v i o r in w a r m and sensitive w a y s even w h e n the child denies the m o t h e r ' s requests, h o w to attend to the c h i l d ' s f o c u s of attention a n d m a i n t a i n and build the c h i l d ' s interest, w h e n to i n t r o d u c e interactions and g a m e s , a n d h o w t o use v o c a b u l a r y - r i c h l a n g u a g e , labeling objects and

actions.

T h e effect on

mothers'

behavior

w a s marked for m a n y dimensions, including w a r m and sensitive behavior, responding appropriately to child's intents, maintaining the child's interest in activities, a n d v e r b a l l y e n c o u r a g i n g the child. E f f e c t sizes f o r such o u t c o m e s r a n g e d a s high a s i S D . T h e e f f e c t o n the c h i l d r e n ' s b e h a v i o r w a s a l s o s u b s t a n t i a l . C h i l dren became m o r e cooperative, w e r e m o r e engaged w h e n interacting w i t h their m o t h e r s , used w o r d s m o r e f r e q u e n t l y , w e r e better able to c o o r d i n a t e their w o r d s with

w h a t they

were attending

to, a n d s c o r e d h i g h e r on a p i c t u r e v o c a b u l a r y test. T h e s e e f f e c t s ranged as high as . 7 0 S D . W e d o not k n o w yet w h a t the long-term effects o f parental interventions are, but there seems to be g o o d reason to be h o p e f u l . T h e benefit-cost ratio of such p r o g r a m s could be very high.

School-Age

Interventions

H o w about interventions for school-age children?

W h a t can

be

done for children w h o have not had p o w e r f u l preschool interventions, or c o u l d be d o n e to sustain the g a i n s e x p e r i e n c e d by children w h o have been in center-based d a y - c a r e p r o g r a m s ? I'll s t a r t w i t h s o m e b a d n e w s — a n d u n f o r t u n a t e l y t h e r e i s a l o t o f it. I n C h a p t e r 4 ( o n i m p r o v i n g s c h o o l s ) I d i s c u s s e d s o m e of the e f f o r t s m a d e to i m p r o v e the a c a d e m i c p e r f o r m a n c e of children

in general.

Sheer a m o u n t of money spent doesn't do

a lot of g o o d f o r s t u d e n t s in g e n e r a l , so we w o u l d not e x p e c t m o n e y b y itself t o n a r r o w the a c h i e v e m e n t g a p b e t w e e n l o w e r and upper-SES students or between minority and white students. Vouchers for attending private schools have been given out to

INTELLIGENCE AND HOW TO GET IT

1132

p o o r a n d minority children, but there is not much evidence that they are the a n s w e r . T h e s a m e is largely true f o r charter schools. S o m e m i g h t do a better j o b than the p u b l i c s c h o o l s — i n fact, y o u will read a b o u t o n e l a t e r — b u t charter schools in general seem t o b e little b e t t e r t h a n t h e p u b l i c s c h o o l s e v e n a f t e r t h e y h a v e been in o p e r a t i o n f o r a w h i l e , and they m a y actually be w o r s e in their early years. A r e there s o m e regular public s c h o o l s that do a partictilarly g o o d job with disadvantaged minority populations? T w o different reports m a i n t a i n that at least s o m e s c h o o l s do a superb job with their underprivileged, minority clientele. O n e report is by a c o n s e r v a t i v e institution, a n d o n e is by a liberal institution. T h e Heritage F o u n d a t i o n , a conservative institution, claims to have f o u n d twenty-one high-poverty schools w h o s e students have a c h i e v e m e n t levels a b o v e the national n o r m s . T h e s e schools arc held up as m a v e r i c k s that e s c a p e f r o m l o w p e r f o r m a n c e by dint of h a v i n g v i s i o n a r y principals w h o are willing to buck the " c u l t of p u b l i c e d u c a t i o n , " f i r e b a d t e a c h e r s , a n d t e a c h the b a s i c s i n s t e a d of progressive nonsense. R i c h a r d R o t h s t e i n , the f o r m e r n a t i o n a l e d u c a t i o n c o l u m n i s t f o r t h e New

York Times, d e b u n k e d t h e s e c l a i m s . A c c o r d i n g to h i m ,

o n l y six of the t w e n t y - o n e s c h o o l s w e r e fully nonselective neighb o r h o o d s c h o o l s . T h e rest w e r e (a) m a g n e t s c h o o l s ; (b) s c h o o l s w h e r e m a n y o f t h e p a r e n t s w e r e " i m p o v e r i s h e d " g r a d u a t e stud e n t s ; (c) s c h o o l s t h a t d i d i n d e e d p r o d u c e h i g h s c o r e s e a r l y o n b y c o n c e n t r a t i n g on the basics such as p h o n i c s , but scores declined precipitously in

l a t e r g r a d e s p r e c i s e l y b e c a u s e the e m p h a s i s o n

the basics p r e c l u d e d learning r e a s o n i n g a n d interpretation skills n e c e s s a r y f o r s u c c e s s i n t h e u p p e r g r a d e s ; o r (d) s c h o o l s w h e r e parents had to a p p l y to get their children accepted, thereby introducing a potentially heavy self-selection bias. The

Education

uncovered

Trust,

a

liberal

organization, claims to

have

1 , 3 2 0 s c h o o l s i n w h i c h a t least h a l f the s t u d e n t s w e r e

b o t h p o o r a n d m i n o r i t y a n d w h o s e test s c o r e s w e r e i n the t o p third f o r t h e i r s t a t e s . T h e c l a i m s a b o u t these s c h o o l s d o n o t h o l d u p

Mind the

12 5

Gap

either, a c c o r d i n g to Rothstein. T h e 1 , 3 2 0 s c h o o l s did in fact h a v e high scores, but in only o n e g r a d e , in o n l y o n e subject, a n d f o r o n l y one year. T h e s e a c c o m p l i s h m e n t s w e r e mostly statistical flukes. Rothstein

gives

an

even

more

bracing

back

of the

hand

to

yet a n o t h e r c l a i m , this o n e b y D o u g l a s R e e v e s , w h o s a y s h e has identified a g r o u p of " 9 0 / 9 0 / 9 0 " schools in M i l w a u k e e w h e r e 90 percent o f the students are p o o r , 9 0 percent are m i n o r i t y , a n d 9 0 percent meet " h i g h a c a d e m i c s t a n d a r d s . " T h o s e s t a n d a r d s turn o u t to be o n l y b a s i c , n o n p r o f i c i e n c y level s c o r e s as d e f i n e d by the state of Wisconsin. H o w about claims that if y o u put poor minority kids into a school with children w h o s e families are well o f f , their a c a d e m i c achievement can front page in

soar? The

2005

(and

New

then

York

Times a n n o u n c e d

repeated

on

its

in another front-page

story in 2 0 0 7 , a n d yet a g a i n in a m a g a z i n e story in 2 0 0 8 ) that such

effects

North

had

Carolina.

been

achieved

Under

the

in

Wake

headline

"As

County Test

in

Raleigh,

Scores

Jump,

R a l e i g h C r e d i t s I n t e g r a t i o n b y I n c o m e , " t h e Times s a i d t h i s : O v e r the last d e c a d e , black and H i s p a n i c students here in W a k e C o u n t y have m a d e such d r a m a t i c strides in standardized reading and math tests that it has c a u g h t the attention of e d u c a t i o n e x p e r t s a r o u n d the c o u n t r y . The main reason f o r the students' d r a m a t i c i m p r o v e m e n t , say o f f i c i a l s and parents in the c o u n t y , w h i c h includes Raleigh and its s p r a w l i n g s u b u r b s , is that the district has m a d e a concerted e f f o r t to integrate the s c h o o l s e c o n o m i c a l l y . T h e article goes on

to

state

that since

2000,

officials

used

income to guide a s s i g n m e n t to s c h o o l s , with the intention of holdi n g t h e p r o p o r t i o n o f l o w - i n c o m e s t u d e n t s t o less t h a n 4 0 p e r c e n t . T h e result? In W a k e C o u n t y , only 40 percent of black students in g r a d e s three through eight scored at g r a d e level on state tests a decade a g o . L a s t

INTELLIGENCE AND HOW TO GET IT

1134

spring, 80 percent did. H i s p a n i c students have m a d e similar strides. O v e r a l l , 91 percent of students in those grades scored at g r a d e level in the spring, up f r o m 79 percent 10 years a g o . U n f o r t u n a t e l y , there is no evidence that schools in Raleigh do a better job for minority students than schools statewide. T h e black/ w h i t e g a p w a s a c t u a l l y slightly less f o r s t u d e n t s in the state as a w h o l e in 2 0 0 4 / 0 5 than it w a s in W a k e C o u n t y . M o r e o v e r , the apparent gains in W a k e C o u n t y by minority students were almost surely due to an easing of statewide standards for proficiency. By the n e w s t a n d a r d s 95

percent of whites were proficient, which

indicates that the s t a n d a r d w a s so lenient it is impossible to get a read on the actual size of the g a p . T h e data c o m p a r i n g W a k e C o u n t y with the state as a w h o l e are e n c o u r a g i n g in one respect, though. T h e y indicate that integration o f l o w - i n c o m e c h i l d r e n w i t h h i g h e r - i n c o m e c h i l d r e n m a y hurt the a c a d e m i c a c h i e v e m e n t of n e i t h e r — a n d m a y result in social gains for both. But we w o u l d have to k n o w much m o r e — f o r example, the S E S level o f b l a c k s a n d w h i t e s both s t a t e w i d e a n d f o r W a k e C o u n t y — b e f o r e we could evidence,

incidentally,

reach that conclusion. T h e r e is g o o d

that

black

and

Hispanic

children

learn

m o r e in integrated c l a s s r o o m s than in majority black or Hispanic classrooms. H o w a b o u t e f f o r t s to i m p r o v e schools by instituting top-tobottom

changes

in

administration

and

curriculum?

We

know

f r o m C h a p t e r 4 that there a r e a lot of such w h o l e - s c h o o l intervent i o n s , i n w h i c h e n t i r e c u r r i c u l a a n d e d u c a t i o n a l s t r a t e g i e s a r e set in place in a s c h o o l . But those interventions tend n o t to p r o d u c e very impressive results f o r students in general, so we have to be skeptical as to w h e t h e r they w o u l d be very successful in reducing the a c h i e v e m e n t g a p . T e a c h e r certification and higher academic degrees do not improve the a c h i e v e m e n t of a n y o n e very m u c h either. E x p e r i e n c e in teaching c o u n t s , t h o u g h , a n d there is a possibility that experience matters m o r e for lower-class than middle-class kids or more for minority

Mind the

12 5

Gap

kids than for whites. T e a c h e r quality also m a k e s a big d i f f e r e n c e for students' achievement scores.

A g a i n , there is the possibility

that teacher quality matters m o r e for p o o r a n d minority kids. We certainly k n o w that M i s s A, heralded in C h a p t e r 4, m a d e a huge difference f o r the p o o r kids in her first-grade class. A n d we k n o w t h a t the p e r f o r m a n c e o f p o o r k i d s a n d o f k i d s w h o h a d b e e n d i s r u p tive in k i n d e r g a r t e n is greatly a f f e c t e d by the quality of instructional s u p p o r t and e m o t i o n a l care that they get in first g r a d e . We also k n o w that s m a l l e r class sizes result in better p e r f o r m a n c e o n a c h i e v e m e n t tests, a n d that the e f f e c t s a r e bigger f o r b l a c k k i d s t h a n f o r w h i t e k i d s — . 3 3 S D v e r s u s .2.5 S D — a n d b i g g e r for poor kids than for middle-class kids. There are s o m e big success stories in K - 1 2 education though. T w o educational programs for poor and minority children—one for math and

one for reading—have

been

shown

to

be quite

effective. T h e math training p r o g r a m is called Project S E E D . It is an enrichment program entists,

and

that hires a n d

engineers

to

teach

t r a i n s m a t h e m a t i c i a n s , sci-

poor

minority

students.

The

p r o g r a m teacher uses Socratic q u e s t i o n i n g to i n t r o d u c e a b s t r a c t mathematical concepts and

students

become active

participants

in the l e s s o n s — t h r o u g h the use of d i a l o g u e , d e b a t e s , a n d c h o r a l r e s p o n s e . T h e r e g u l a r t e a c h e r sits i n o n all s e s s i o n s . P r o j e c t S E E D is not a replacement for the regular m a t h e m a t i c s c u r r i c u l u m but an

add-on.

O n e study

of Project S E E D ' s effectiveness, carried

out in D a l l a s , c o m p a r e d the C a l i f o r n i a A c h i e v e m e n t T e s t ( C A T ) s c o r e s o f 2.44 f o u r t h - g r a d e s t u d e n t s i n S E E D c l a s s r o o m s w i t h 2 4 4 students in the s a m e s c h o o l s w h o did tion and

not have S E E D

instruc-

2 4 4 students w h o w e r e not in S E E D schools but w e r e

deemed c o m p a r a b l e to them. T h e S E E D students outscored the comparison-group students by . 3 7 S D — a very significant benefit. But S E E D students o u t p e r f o r m e d the n o n - S E E D students in their o w n school b y o n l y . 1 9 S D . A r g u m e n t s a s t o w h i c h i s the m o r e appropriate control can be m a d e both w a y s , and it m a k e s a g o o d deal of difference w h i c h side o n e c o m e s d o w n on. A gain of . 3 7

INTELLIGENCE AND HOW TO GET IT

1136

SD is surely w o r t h the cost, w h i c h w a s not great; a gain of . 1 9 SD m a y n o t be. Several reading p r o g r a m s geared to minority and poor children h a v e been d e v e l o p e d , of w h i c h o n e of the m o s t p r o m i s i n g is R e a d i n g R e c o v e r y ( D e s c u b r i e n d o L a L e c t u r a i n its S p a n i s h v e r s i o n ) . R e a d i n g R e c o v e r y is a t u t o r i n g p r o g r a m f o r l o w - p e r f o r m i n g firstgraders that w a s d e v e l o p e d by O h i o State University researchers. T u t o r s p r o v i d e a daily o n e - o n - o n e 3 0 - m i n u t e lesson f o r twelve to twenty w e e k s . Children read stories they already k n o w verbally, read a story

they

read

the d a y

before, and

write stories. T h e

O h i o State g r o u p c o n d u c t e d r a n d o m i z e d studies t o e v a l u a t e the p r o g r a m . T h e y f o u n d effect sizes r a n g i n g f r o m . 5 7 t o . 7 2 S D for m o s t i n d i c a t o r s o f r e a d i n g p r o f i c i e n c y . T h e e f f e c t sizes f a d e d o v e r t i m e , t h o u g h t h e y w e r e still d e t e c t a b l e a t a b o u t .2.0 S D i n t h e t h i r d grade.

One

independent study

evaluating

the S p a n i s h - l a n g u a g e

p r o g r a m d e m o n s t r a t e d e f f e c t sizes r a n g i n g f r o m a b o u t 1 . 7 0 S D s . T h i s f i n d i n g w o u l d need t o b e duplicated

1.00 to

before we

c o u l d p l a c e m u c h c o n f i d e n c e i n it. T h e r e is at least o n e e x t r e m e l y i m p o r t a n t e x c e p t i o n to the rule that whole-school

interventions, and charter schools, have only

m o d e s t effects on student a c h i e v e m e n t : the K n o w l e d g e Is P o w e r Program, or KIPP. Michael Feinberg and David Levin, two Houston-area elementary-school teachers with four years of teaching e x p e r i e n c e between t h e m , f o u n d e d this e x t r a o r d i n a r i l y a m b i t i o u s e d u c a t i o n a l p r o j e c t i n 1 9 9 4 . T h e y d e s i g n e d i t a r o u n d the needs o f p o o r children, especially minority children. T h e y freely admit that they invented the p r o g r a m as they w e n t a l o n g . But they had help f r o m a m u c h m o r e experienced m e n t o r — H a r r i e t t Ball—a teacher w h o had g r o w n up in the racially segregated n e i g h b o r h o o d s of H o u s t o n and w h o w a s k n o w n for having classes with students w h o w e r e well b e h a v e d and high achieving. F e i n b e r g a n d Levin d e v e l o p e d a t y p e of s c h o o l , initially mostly for middle-school children, based on 7 : 3 0 a.m. to 5:00 p.m. school d a y s (yes, 9Vi h o u r s ) , m a n d a t o r y a t t e n d a n c e f o r three a d d i t i o n a l w e e k s in the s u m m e r , a

half-day of Saturday classes biweekly,

Mi fid the Gap

137

visits t o students'

homes, an

insistence on

kindness and good

b e h a v i o r , the principal h a v i n g the p o w e r to hire a n d fire teachers, c o o p e r a t i o n a m o n g teachers, and a system of r e w a r d s and penalties for behavior and a c a d e m i c accomplishment. T h e huge a m o u n t of extra c o n t a c t time a l l o w s for the K I P P students to get e x p o s u r e to w h a t u p p e r - m i d d l e - c l a s s students get t h r o u g h their homes and expensive public or private schools—sports, museums, dance, art, musical instruments, theater, and

photography. The

first t w o s c h o o l s — i n H o u s t o n a n d the B r o n x — s c o r e d highest o n a c h i e v e m e n t tests of a n y s c h o o l s in their a r e a s . Since 2.001

KIPP

has begun to e x p a n d with financial support f r o m Doris and D o n Fisher, the f o u n d e r s o f G a p stores. M o s t K I P P s c h o o l s are charter schools that are essentially

franchises of the K I P P F o u n d a t i o n .

T w o other similar p r o g r a m s , called A c h i e v e m e n t First a n d N o r t h S t a r , h a v e been less well r e s e a r c h e d . KIPP's students are economically

disadvantaged

as

a

group.

M o r e than 80 percent are eligible for federal free or subsidized lunches. M o s t are African American or Hispanic. K I P P maintains that " w h i l e the a v e r a g e f i f t h - g r a d e r enters K I P P in the b o t t o m t h i r d o f t e s t - t a k e r s n a t i o n w i d e (2.8th p e r c e n t i l e ) , t h e a v e r a g e K I P P eighth-grader nationwide

outperforms

(74th

nearly

percentile)

on

three

out

of four

norm-referenced

test-takers

reading

and

math assessments." But s o m e K I P P schools h a v e posted losses f o r their students (to K I P P ' s c r e d i t , b y its o w n a d m i s s i o n ) , a n d K I P P ' s c l a i m s f o r s u c c e s s e s h a v e b e e n b a s e d m o s t l y o n its o w n t e a c h e r s ' t e s t s a n d not on independent research. H o w e v e r , S R I International conducted an independent study of K I P P s c h o o l s in the San Francisco B a y A r e a , in the early y e a r s of this c e n t u r y , a n d I r e p o r t on it at length here. I n t h e f i v e B a y A r e a K I P P s c h o o l s , 72. p e r c e n t o f t h e c h i l d r e n were economically disadvantaged and

75

percent were African

A m e r i c a n or L a t i n o . E a c h school in the study w a s c o m p a r e d to t w o comparison schools that were similar socioeconomically and with respect to minority c o m p o s i t i o n . T h e K I P P schools began in

INTELLIGENCE AND HOW TO GET IT

1138

2 0 0 2 / 0 3 with an entering class of fifth-graders and added a class each year. Principals study the K I P P m o d e l f o r a

y e a r b e f o r e they get

their o w n s c h o o l s . But the K I P P m o d e l d o e s not prescribe a particular instructional approach or curriculum, so teachers do not h a v e to learn a n e w s y s t e m required by the m o d e l , in c o n t r a s t to m o s t w h o l e - s c h o o l r e f o r m s . At the time of the study, a b o u t half the B a y A r e a K I P P teachers c a m e f r o m the T e a c h f o r A m e r i c a p r o g r a m , a n d their m e d i a n teaching e x p e r i e n c e before joining KIPP w a s t w o years. It is possible f o r children to fail in K I P P schools. Principals believe that the o p t i o n to hold students b a c k is essential because t h e s c h o o l " c o u l d n ' t let o t h e r k i d s s e e t h a t k i d s w h o d i d n o t h i n g could m o v e a h e a d . " It is impressed on staff, students, and parents that certain behaviors are d e m a n d e d of them. T h e K I P P credo is " I f there is a p r o b l e m , we l o o k f o r a s o l u t i o n . If there is a better w a y , w e f i n d it. I f w e n e e d h e l p , w e a s k . I f a t e a m m a t e n e e d s h e l p , we give it." S o m e sample K I P P slogans are " W o r k hard, be nice," " A l l of us will l e a r n , " a n d " K I P P s t e r s do the right thing w h e n no one is w a t c h i n g . " Students earn " p a y c h e c k s " each w e e k , based on a point system that a d d s on to their v a l u e or subtracts f r o m

it depending on

b e h a v i o r a n d a c a d e m i c p e r f o r m a n c e . T h e p a y c h e c k can b e used to buy items f r o m the K I P P store, including snacks and school supplies, a n d to buy a t t e n d a n c e on field trips. Students get publicly " b e n c h e d " f o r b a d b e h a v i o r a n d f a i l u r e t o d o w o r k . A t o n e school, students have to go three d a y s in a r o w without getting d e d u c t i o n s f r o m their p a y c h e c k s in o r d e r to get o f f the bench. T e a c h e r s i n s i s t e d t o S R I r e s e a r c h e r s t h a t all s t u d e n t a c t i o n s h a v e consequences.

But teachers also maintained that good

behavior

w a s not due to fear. " W e ' v e never had a

kid talk

back to a

teacher, and

we've

n e v e r had k i d s fight. I d o n ' t a t t r i b u t e this to the discipline system. It's f r o m setting e x p e c t a t i o n s f r o m the start. T h e smallest detail w a s c a l l e d o u t . . . It's b e c a u s e k i d s believe that this is an

Mind the

12 5

Gap

extraordinary place, and w e ' v e taught them that. I d o n ' t think they d o n ' t tease b e c a u s e they a r e a f r a i d of the [bench). It's just s o m e t h i n g that they w o u l d not do at K I P P . T h i s is the o n e s c h o o l t h e y ' v e been t o w h e r e there's n o teasing. T h e y feel s a f e , a n d they are learning m o r e . " A n o t h e r teacher s a i d , " A t this s c h o o l , it's o k a y t o b e s m a r t , a n d that's something that is lacking at most inner-city public schools . . . In | m y f o r m e r d i s t r i c t ) , I w o r k e d w i t h t r a d i t i o n a l l y u n d e r served kids a n d f o u n d the s c h o o l s to be an i n a d e q u a t e solution to kids' needs . . . I visited a K I P P school |nearby], a n d the school w a s like a n o a s i s . " C o m m e n t s of students s h o w that they are well a w a r e of the difference between the K I P P s c h o o l a n d others they h a v e attended. " E v e r y o n e is committed to learning." " T h e other school w a s not challenging e n o u g h , and I've f o u n d it has been h e r e . "

"Now I

r e a l i z e y o u h a v e t o w o r k t o g e t t o c o l l e g e . " I n all t h e s c h o o l s , students said there w e r e f e w e r fights, if in fact there w e r e any at all, than in p r e v i o u s s c h o o l s they h a d attended: " A t this s c h o o l , something holds me back from fighting." O f c o u r s e the d e m a n d s o n t e a c h e r s are e n o r m o u s . T h e y m u s t be in school f r o m 7 : 1 5 a . m . to 5 : 1 5 p.m. and are usually there longer. In addition to planning c u r r i c u l u m , they p r o v i d e instruction, m o n i t o r study halls, lead e n r i c h m e n t activities like trips to z o o s a n d m u s e u m s , tutor, a n d call parents at night to discuss their children's p e r f o r m a n c e . T h e y also w o r k several w e e k s during the summer and

every other S a t u r d a y . N o t surprisingly, they

emotional exhaustion.

And

fight

in general, most KIPP teachers say

they will be able to stay for only a f e w years. W h a t e d u c a t i o n a l r e s u l t s d o e s all this p r o d u c e ? C h i l d r e n i n K I P P s c h o o l s in the B a y A r e a succeed at levels well b e y o n d w h a t w o u l d b e e x p e c t e d c o n s i d e r i n g their d e m o g r a p h i c c o m p o s i t i o n . T h e children w e r e given the reading, l a n g u a g e arts, a n d m a t h S t a n f o r d A c h i e v e m e n t T e s t ( S A T 1 0 ) , w h i c h is n o r m e d nationally, in the fall and spring. For fifth-graders, fall scores indicate w h e r e students are a t the outset o f the K I P P e x p e r i e n c e . T h e i m p r o v e m e n t f r o m

INTELLIGENCE AND HOW TO GET IT

1140

fall t o s p r i n g w a s c a l c u l a t e d i n t e r m s o f t h e p e r c e n t a g e o f s t u d e n t s scoring at or a b o v e the 50th percentile f o r national n o r m s at each p o i n t . In the fall, f o r f i f t h - g r a d e l a n g u a g e arts, the p r o p o r t i o n of s t u d e n t s s c o r i n g a t t h a t level w a s z 5 p e r c e n t ( o n a v e r a g e f o r all c l a s s e s a t t h e f o u r s c h o o l s t h a t g a v e t h e test), s l i g h t l y m o r e t h a n w e w o u l d e x p e c t g iven the d e m o g r a p h i c characteristics o f the s c h o o l s . In the s p r i n g , it w a s 44 percent, s u b s t a n t i a l l y higher than we w o u l d e x p e c t g iv en the d e m o g r a p h i c s . In the fall, f o r f i f t h - g r a d e m a t h , the p r o p o r t i o n w a s 37 percent; in the spring it w a s 65 percent. G a i n s for sixth-graders were also m a r k e d . T h e s e increases are extremely large. T h e y indicate that a f t e r just o n e y e a r at a K I P P s c h o o l , disa d v a n t a g e d and largely minority children were scoring close to or a b o v e t h e n a t i o n a l a v e r a g e o n s t a n d a r d i z e d tests. S i n c e s c o r e s w e r e not very impressive at the beginning of the year f o r those s a m e c h i l d r e n , we c a n rule o u t the possibility that self-selection is entirely responsible f o r the o u t c o m e in the spring. I n t h e s p r i n g , all c h i l d r e n (at all f i v e s c h o o l s ) w e r e a l s o g i v e n t h e California Achievement Test, which is required by law. For English L a n g u a g e A r t s , 4 3 p e r c e n t o f K I P P f i f t h - g r a d e r s s c o r e d a t t h e level o f p r o f i c i e n t o r a b o v e , v e r s u s 1 9 p e r c e n t o f the f i f t h - g r a d e r s at comparison

schools chosen

for their d e m o g r a p h i c similarity

t o the K I P P s c h o o l s . F o r M a t h e m a t i c s , 5 5 percent o f K I P P fifthg r a d e s t u d e n t s s c o r e d at the level of p r o f i c i e n t or a b o v e , v e r s u s zo percent o f c o m p a r i s o n - s c h o o l students. Results o n the C A T w e r e entirely c o m p a r a b l e f o r the sixth g r a d e . A g a i n , these results are extremely

striking.

(Baseline,

beginning-of-the-year C A T scores

w e r e c o m p a r a b l e f o r K I P P a n d the c o m p a r i s o n s c h o o l s . ) I have violated my o w n implicit research standards in reporting the S R I s t u d y . Students w e r e not r a n d o m l y assigned to be in K I P P schools versus control schools. And it could be done: KIPP schools s o m e t i m e s h a v e w a i t i n g lists a n d u s e l o t t e r i e s t o p i c k s t u d e n t s . Unchosen children

could

be assigned

to a

randomized control

g r o u p a n d g i v e n t h e s a m e t e s t s a s t h e K I P P s t u d e n t s . K I P P itself i s w o r r i e d a b o u t p i c k i n g the c r e a m o f the c r o p . T o their credit, s o m e schools h a v e taken steps to ensure that they get as m a n y

Mind the

12 5

Gap

underprivileged m i n o r i t y students as p o s s i b l e , the p o p u l a t i o n they regard as their target. But there is no q u e s t i o n that there is a severe self-selection p r o b lem, b e c a u s e parents, not researchers, decide w h e t h e r their kids will get into a K I P P s c h o o l . T h i s a u t o m a t i c a l l y m e a n s that s o m e of the p e r f o r m a n c e a d v a n t a g e s o f the K I P P students m i g h t c o m e not f r o m the s c h o o l , b u t f r o m h a v i n g p a r e n t s , a n d p e r h a p s o t h e r a d v a n t a g e s , t h a t w o r k t o t h e i r b e n e f i t . T h e q u e s t i o n is, c o u l d s e l f - s e l e c t i o n h a v e p r o d u c e d the results that w e r e o b t a i n e d f r o m the students? As a start to a n s w e r i n g this q u e s t i o n , we c a n at least be r e a s o n ably sure that attrition is not a m a j o r c o n t r i b u t o r to the f a v o r a b l e results. O n l y a b o u t 9 p e r c e n t o f s t u d e n t s a t s c h o o l s s t u d i e d b y S R I International exit each year, s o m e t o a v o i d being held b a c k . T h e schools

themselves

discourage

some

students

from

continuing,

though no one is ever actually expelled. But relatively f e w leave, so self-selection out of the s c h o o l seems not to be a serious c o n t r i b u t o r to the high scores of K I P P children. In short, though I do not d o u b t that students w h o s e parents choose K I P P schools are m o r e p r o m i s i n g than their d e m o g r a p h i c s w o u l d indicate, I c a n n o t i m a g i n e that the results o b t a i n e d by K I P P could be primarily due to self-selection. H o w e v e r , before society invests a huge a m o u n t of m o n e y in K I P P s c h o o l s , s o m e fully randomized studies should be conducted. I h a v e little d o u b t t h a t s u c h r a n d o m i z e d s t u d i e s w i l l s h o w t h a t poor minority children—at any

rate, those w h o s e

parents care

e n o u g h to get them into K I P P s c h o o l s — c a n p e r f o r m a c a d e m i c a l l y at levels as high as those that a p p r o x i m a t e t h o s e of m i d d l e - c l a s s whites. T h e next step will be to find out whether children w h o s e parents are not so concerned a b o u t their children's education can also benefit f r o m KIPP-type programs.

High You

School Math for may

have

seen

Poor Hispanics

Stand and

Deliver,

the

movie

about

math

teacher J a i m e Escalante's achievement in getting East L o s Ange-

INTELLIGENCE AND HOW TO GET IT

1142

les

barrio s t u d e n t s — w h o typically did

not g r a d u a t e f r o m high

s c h o o l — t o p a s s A P c a l c u l u s a t h i g h e r r a t e s t h a n s t u d e n t s a t rich B e v e r l y H i l l s H i g h , a n d f o r t h a t m a t t e r a t m o s t elite h i g h s c h o o l s in the c o u n t r y . But is the story told by the m o v i e true? T h e r e ' s g o o d n e w s and bad n e w s a b o u t Escalante's feat. M o s t i m p o r t a n t l y , that it h a p p e n e d is perfectly true. But u n f o r t u n a t e l y it did not h a p p e n in the w a y the m o v i e implies: I n real life E s c a l a n t e d i d n o t a n n o u n c e t o u n s u s p e c t i n g s e n i o r s t h a t h e w a s g o i n g t o m a k e t h e m i n t o m a t h w h i z z e s t h a t y e a r . H e built up m a t h p r o g r a m s at junior high feeder schools that brought highly p r e p a r e d s t u d e n t s i n t o his t h r e e - y e a r h i g h s c h o o l . A n d h e m a d e s u r e his s t u d e n t s h a d e x c e l l e n t c o u r s e s i n h i g h s c h o o l m a t h b e f o r e t h e y e v e r c a m e i n t o his c l a s s . B u t all t h a t w a s a c c o m p l i s h e d w i t h s u b stantial o p p o s i t i o n f r o m the first principal h e w o r k e d under. T h i n g s began to m o v e s m o o t h l y only w h e n a sympathetic principal c a m e on b o a r d (and b a n n e d students f r o m being on athletic t e a m s if they m a i n t a i n e d less t h a n a C a v e r a g e ) . A n d t h e n E s c a l a n t e h a d to f i g h t a teachers' u n i o n w h e n his classes g r e w to be m u c h larger than union rules a l l o w e d . He c o u l d n ' t find e n o u g h g o o d teachers to increase the n u m b e r of classes taught, so classes g r e w t o o large. T h e n t h e s y m p a t h e t i c p r i n c i p a l w a s r e p l a c e d b y o n e less s y m p a t h e t i c . E s c a l a n t e l e f t his s c h o o l o v e r t h e c l a s s - s i z e i s s u e a n d o t h e r p r o b l e m s . T h e p r o g r a m b e c a m e p r o g r e s s i v e l y less s u c c e s s f u l a f t e r his d e p a r t u r e , t h o u g h t h e h i g h s c h o o l c o n t i n u e s t o d o f a r b e t t e r w i t h A P m a t h t h a n m o s t s c h o o l s o f its t y p e . T h e importance of Escalante's achievement is

very great.

It

serves as an e x i s t e n c e p r o o f f o r the c o n t e n t i o n that d i s a d v a n t a g e d m i n o r i t y k i d s c a n f u n c t i o n in m a t h at a level f a r higher than the national average.

Inexpensive

hiterventions

by

Social

Psychologists

S o m e o f m y f e l l o w social p s y c h o l o g i s t s h a v e recently c o m e o n the education

scene, bringing interventions that are very simple to

carry out and extraordinarily cost-effective.

Mind the

12 5

Gap

M a n y A m e r i c a n s believe that abilities are essentially fixed at birth: either y o u h a v e m a t h ability or y o u d o n ' t . O t h e r s believe abilities are highly susceptible to m a n i p u l a t i o n : if y o u w o r k h a r d , y o u will be better at a given skill than if y o u d o n ' t . C a r o l D w e c k and

her c o w o r k e r s h a v e m e a s u r e d

attitudes a b o u t ability

in

a

g r o u p of mostly minority junior high school students, asking f o r beliefs a b o u t such questions as " Y o u have a certain a m o u n t of intelligence, a n d y o u really c a n ' t d o m u c h t o c h a n g e it" a n d " Y o u can a l w a y s greatly c h a n g e h o w intelligent y o u a r e . " T h e y s h o w e d , not surprisingly, that students w h o believe that ability is a matter of hard w o r k get higher g r a d e s than students w h o believe ability c o m e s f r o m the genes. D w e c k a n d her c o l l e a g u e s then tried to c o n v i n c e a g r o u p of poor

minority

junior

high

school

students

that

intelligence

is

highly malleable a n d can be d e v e l o p e d by hard w o r k . T h e thrust of the intervention w a s that learning c h a n g e s the brain by f o r m ing n e w n e u r o l o g i c a l c o n n e c t i o n s a n d that students are in c h a r g e of this c h a n g e process. D w e c k r e p o r t e d that s o m e of her t o u g h junior high s c h o o l b o y s w e r e r e d u c e d to tears by the n e w s that their intelligence w a s substantially u n d e r their c o n t r o l . Students exposed

t o the i n t e r v e n t i o n

worked

h a r d e r , a c c o r d i n g to their

teachers, and got higher grades than students in a control condit i o n . T h e i n t e r v e n t i o n w a s m o r e e f f e c t i v e f o r c h i l d r e n w h o initially believed that intelligence w a s a m a t t e r of g e n e s t h a n it w a s for children w h o already w e r e inclined to believe that it w a s a matter of hard w o r k . Joshua

Aronson

experiments,

with

and

his

dramatic

colleagues results.

have

One

performed

study

similar

was conducted

with p o o r minority students in T e x a s w h o w e r e just beginning junior

high

school.

Their

intervention

was

intensive

and

the

results w e r e d r a m a t i c . E a c h student in the T e x a s s t u d y w a s a s s i g n e d a c o l l e g e - s t u d e n t m e n t o r f o r their first year in junior high. T h e m e n t o r s discussed a variety of issues related to s c h o o l a d j u s t m e n t . T h e m e n t o r s f o r the control participants gave information about drugs and encouraged

INTELLIGENCE AND HOW TO GET IT

1144

their students to a v o i d t a k i n g them. E x p e r i m e n t a l - g r o u p m e n t o r s told their students a b o u t the e x p a n d a b l e nature of intelligence and t a u g h t them h o w the brain can m a k e n e w c o n n e c t i o n s t h r o u g h o u t life. E v e r y student w a s e x p o s e d to a W e b p a g e that r e i n f o r c e d the m e n t o r ' s m e s s a g e . F o r s t u d e n t s i n the e x p e r i m e n t a l g r o u p , this W e b site s h o w e d a n i m a t e d pictures o f the b r a i n , i n c l u d i n g i m a g e s of neurons and dendrites, and provided narratives explaining how the brain f o r m s n e w c o n n e c t i o n s w h e n n e w p r o b l e m s are being solved. T h e m e n t o r s a l s o helped the sttidents design a W e b p a g e in w h i c h the s t u d e n t s p r e s e n t e d , t h r o u g h w o r d s a n d pictures o f their o w n m a k i n g , the m e s s a g e that the m e n t o r had been presenting. T h e e f f e c t s o f the i n t e r v e n t i o n w e r e very p o w e r f u l . O n the m a t h p o r t i o n o f the T e x a s A s s e s s m e n t o f A c a d e m i c Skills ( T A A S ) , perf o r m a n c e b y m a l e students e x p o s e d t o the intervention w a s .64 SD higher than f o r males not e x p o s e d to the intervention. For f e m a l e s , w h o tend t o h a v e w o r r i e s a b o u t w h e t h e r their gender m a k e s t h e m less t a l e n t e d i n m a t h , t h e d i f f e r e n c e w a s 1 . 1 3 S D s . F o r r e a d i n g , s t u d e n t s e x p o s e d t o t h e i n t e r v e n t i o n d i d .52. S D better than s t u d e n t s in the c o n t r o l g r o u p . D a p h n a O y s e r m a n a n d her c o w o r k e r s set u p a n e l a b o r a t e interv e n t i o n w i t h p o o r m i n o r i t y j u n i o r high s c h o o l students. T h e y ran several sessions designed to m a k e the students think a b o u t w h a t kind of future they w a n t e d to have, w h a t difficulties they w o u l d likely h a v e a l o n g the w a y , h o w they c o u l d deal with those difficulties, a n d w h i c h of their friends w o u l d be m o s t helpful in dealing with them. These were supplemented with sessions during which students w o r k e d in small g r o u p s on h o w to deal with everyday p r o b l e m s , social difficulties, a c a d e m i c issues, and the process of working toward

high

school

graduation.

The

intervention

had

a m o d e s t e f f e c t o n g r a d e p o i n t a v e r a g e o f .2.3 S D , a m o d e r a t e l y large e f f e c t of . 3 6 SD on s t a n d a r d i z e d tests, a n d a very big effect on likelihood of retention in g r a d e of .60 S D . Small interventions can also m a k e a difference in college. M o s t students w o r r y a b o u t social acceptance and fitting in on c a m p u s , but f o r minority students these concerns can be particularly w o r -

Mind the

12 5

Gap

risome. If they fail to m a k e friends, because there a r c not that m a n y m i n o r i t y s t u d e n t s o n c a m p u s a n d b e c a u s e t h e y m a y f e e l ill at ease with majority students, they m a y begin to w o n d e r if they b e l o n g on c a m p u s . It is c o m m o n f o r m i n o r i t y students'' m o t i v a t i o n to decline and f o r their g r a d e point a v e r a g e to s u f f e r as they go through school. Social

psychologists

Gregory

Walton

and

Geoffrey

Cohen

reasoned that lagging p e r f o r m a n c e could be nipped in the bud if minority students k n e w that w o r r i e s a b o u t social acceptance w e r e c o m m o n f o r all s t u d e n t s , r e g a r d l e s s o f e t h n i c i t y , a n d t h a t t h e i r s i t u a t i o n w o u l d likely i m p r o v e i n t h e f u t u r e . T h e r e s e a r c h e r s p e r f o r m e d a m o d e s t intervention with black students at a prestigious p r i v a t e university. T h e y invited black a n d w h i t e f r e s h m e n to participate in a p s y c h o l o g y study at the end of their f r e s h m a n year. T h e intent of the e x p e r i m e n t e r s w a s t o c o n v i n c e a n intervention g r o u p that w o r ries a b o u t s o c i a l a c c e p t a n c e w e r e c o m m o n b u t t e n d e d t o v a n i s h a s they d e v e l o p e d m o r e friendships. T h e e x p e r i m e n t e r s e x p e c t e d that this w o u l d h e l p b l a c k s t u d e n t s t o r e a l i z e t h a t t h e b e s t w a y t o u n d e r stand their social difficulties w a s not in t e r m s of their race ( " I g u e s s m y k i n d o f p e o p l e d o n ' t r e a l l y b e l o n g a t this k i n d o f p l a c e " ) a n d t o r e p l a c e t h a t w i t h t h e belief t h a t t h e i r e x p e r i e n c e s w e r e s h a r e d ("I guess e v e r y b o d y has these kinds of p r o b l e m s " ) . T h e researchers b e l i e v e d t h a t r e c o g n i t i o n o f t h e i r c o m m o n p r o b l e m — a n d its p r o b able s o l u t i o n — w o u l d likely k e e p the students f r o m w o r r y i n g a b o u t belonging and help them f o c u s on a c a d e m i c achievement. T o drive the point h o m e , W a l t o n a n d C o h e n h a d s t u d e n t s i n the intervention g r o u p write an essay a b o u t the likelihood of i m p r o v e m e n t in their social situation in the f u t u r e a n d d e l i v e r a speech in f r o n t of a v i d e o c a m e r a , w h i c h they w e r e told w o u l d be s h o w n to n e w students a t the s c h o o l " s o that they k n o w w h a t college will be like." T h e investigators then m e a s u r e d a c a d e m i c a c h i e v e m e n t b e h a v i o r o v e r the n e x t w e e k , a s well a s the s t u d e n t s ' g r a d e p o i n t a v e r a g e the subsequent semester. T h e intervention had a big positive effect on blacks but not on w h i t e s . I n the p e r i o d a f t e r the i n t e r v e n t i o n , b l a c k s r e p o r t e d s t u d y -

INTELLIGENCE AND HOW TO GET IT

1 146

ing more, contacting professors more, and attending more review sessions and study g r o u p meetings. T h e subsequent term, grades of the b l a c k s in the intervention g r o u p reflected these behaviors: their g r a d e s w e r e a full s t a n d a r d d e v i a t i o n higher than those of blacks in the control g r o u p .

College as a Gap Reducer I t t u r n s o u t t h a t c o l l e g e itself h a s a h u g e e f f e c t o n t h e i n t e l l e c t u a l a b i l i t i e s o f b l a c k s , s u b s t a n t i a l l y m o r e t h a n its e f f e c t o n w h i t e s . T h e black/white IQ g a p g r o w s in high school. S o m e hereditarians interpret this fact to indicate that the genes assert themselves m o r e a n d m o r e o v e r the c o u r s e o f d e v e l o p m e n t . A t each higher level of e d u c a t i o n , t h e r e f o r e , b l a c k s c o u l d be e x p e c t e d to be farther and

farther behind. Herrnstein and

M u r r a y , for example,

m a i n t a i n e d that it w a s unlikely that e d u c a t i o n b e y o n d high school w o u l d serve to reduce the racial g a p in IQ. D a t a s h o w i n g t h a t the b l a c k / w h i t e g a p g r o w s d u r i n g high s c h o o l come

from

the

National

L.ongitudinal

Survey

of

Youth,

which

a d m i n i s t e r e d t h e A r m e d F o r c e s Q u a l i f i c a t i o n T e s t ( A F Q T ) . T h a t test is a portion of the entire ability battery that the a r m e d forces gives t o p o t e n t i a l s o l d i e r s . T h e A F Q T c o r r e l a t e s s o h i g h l y w i t h intelligence tests t h a t it is a p p r o p r i a t e to r e g a r d it as a m e a s u r e of I Q . T h e test w a s g i v e n t o p a r t i c i p a n t s i n the s u r v e y a t d i f f e r e n t p o i n t s i n their e d u c a t i o n a l c a r e e r f r o m t h e a g e o f f o u r t e e n t o the a g e o f t w e n t y - o n e . There is no question that, as Herrnstein and M u r r a y showed, b l a c k a b i l i t y i n c r e a s e s less in high s c h o o l than d o e s w h i t e ability. T h e i n c r e a s e in the size of the g a p is g r e a t e n o u g h to be quite disturbing.

Blacks

start out

high

school

with

scores

less t h a n

three-fifths of a s t a n d a r d deviation l o w e r on the A F Q T than white scores, but end high school with scores a l m o s t a w h o l e s t a n d a r d deviation lower than white scores. P s y c h o l o g i s t J o e l M y e r s o n a n d h i s c o w o r k e r s set o u t t o d e t e r m i n e w h e t h e r the s a m e d i s m a l f a i l u r e o f g r o w t h o c c u r s f o r b l a c k s in college. Based on the theory that ability differences m a n i f e s t

Mind the

12 5

Gap

t h e m s e l v e s m o r e a n d m o r e o v e r t i m e , w e w o u l d e x p e c t less v a l u e added to IQ for blacks than f o r w h i t e s in college, resulting in a g a p larger than that f o u n d in high school. W h a t M y e r s o n a n d his c o l l e a g u e s f o u n d i s the o p p o s i t e . A t the end o f high s c h o o l , black s t u d e n t s w h o ultimately g r a d u a t e d f r o m college performed m o r e than i SD w o r s e than white students w h o ultimately finished college.

But the w h i t e students g a i n e d

very

little i n I Q o v e r t h e c o u r s e o f c o l l e g e , w h e r e a s t h e b l a c k s t u d e n t s gained IQ at a remarkable clip, ending up with an average IQ only a little m o r e t h a n . 4 0 S D b e l o w t h e a v e r a g e f o r w h i t e s . T h i s d i f f e r ence in v a l u e a d d e d by a c o l l e g e e d u c a t i o n is h u g e . W h y do blacks gain so m u c h in college? It m a y m a k e m o r e sense to a s k w h y they g a i n e d s o little i n h i g h s c h o o l . T h e m o s t o b v i o u s a n s w e r to that question is that blacks go to w o r s e high s c h o o l s than whites. A s e c o n d a n s w e r is t h a t p r e s s u r e n o t to a c t w h i t e is h a r d e r to resist in high s c h o o l t h a n in c o l l e g e (if t h e p r e s s u r e e v e n e x i s t s at c o l l e g e ) . A t h i r d p o s s i b l e a n s w e r lies i n t h e r e s e a r c h o n s t e r e o t y p e t h r e a t , w h i c h d e m o n s t r a t e s the r e m a r k a b l e v a r i a t i o n i n b o t h test p e r f o r mance and

motivation

a m o n g black students, depending on

the

n a t u r e o f the s o c i a l c i r c u m s t a n c e s t h e y f a c e . F o r e x a m p l e , S t e e l e a n d A r o n s o n ' s e x p e r i m e n t a l r e s e a r c h d o c u m e n t e d r e m a r k a b l y b e t t e r test p e r f o r m a n c e a m o n g b l a c k s t u d e n t s w h e n t h e test w a s p r e s e n t e d i n a n o n t h r e a t e n i n g w a y — t h a t is, w h e n t e s t - t a k e r s w e r e n ' t c o n f r o n t e d with the explicit scrutiny of their intellectual abilities, p r e s u m a b l y because doing so m a k e s them a n x i o u s that their p e r f o r m a n c e will m a r k them as fitting the stereotype of intellectual inferiority. In addition t o i m p a i r m e n t o n tests, b l a c k h i g h s c h o o l s t u d e n t s a r e m o r e likely t h a n w h i t e s t u d e n t s t o a d a p t t o this e v a l u a t i v e d i s c o m f o r t i n unhelpful w a y s , such as avoiding challenge and disengaging f r o m academic pursuits, which are characteristic responses to stereotype t h r e a t seen a m o n g m i d d l e - a n d h i g h - s c h o o l - a g e s t u d e n t s . O n e s t u d y that f o l l o w e d black students o v e r their high s c h o o l c a r e e r s f o u n d a particularly sharp decline in black males' e n g a g e m e n t with a c a d e m ics a s t h e y p r o g r e s s e d t h r o u g h h i g h s c h o o l , s o t h a t b y t h e t i m e t h e y w e r e in t w e l f t h g r a d e there w a s no c o n n e c t i o n b e t w e e n their feel-

INTELLIGENCE AND HOW TO GET IT

1 148

ings of s e l f - w o r t h a n d their a c a d e m i c achievement. T h e s e responses seem particularly likely a m o n g students w h o buy into the stereotypes a b o u t their g r o u p . A n o t h e r long-term study f o u n d a direct link b e t w e e n s t u d e n t s ' w o r r i e s t h a t t h e n e g a t i v e s t e r e o t y p e s a b o u t their g r o u p m i g h t b e t r u e a n d t h e i r later r e d u c t i o n i n e f f o r t . S o t h e circumstances that m a x i m i z e stereotype threat m a y

be especially

prevalent in high school. But the truth

is, w e d o n o t k n o w t h e r e a s o n s f o r t h e b l a c k

gains in college. W h a t we do k n o w

is that college produces a

h u g e r e d u c t i o n i n the ability g a p . W e a l s o k n o w that w e h a v e yet a n o t h e r i m p o r t a n t piece of e v i d e n c e c o n t r a d i c t i n g the idea that the IQ g a p increases w i t h a g e b e c a u s e of a genetic deficiency that m a n i f e s t s itself m o r e o v e r t i m e . T h e I Q g a p a c t u a l l y n a r r o w s v e r y substantially o v e r the college years.

Summing

Up

So w h a t do we k n o w about intervention with minority children a n d the p o o r ? S e v e r a l very striking things. P e r h a p s the m a i n lesson is that w h a t w o r k s and w h a t doesn't is an empirical question. S o m e early c h i l d h o o d p r o g r a m s that seem very reasonable d o not have very b i g — o r very lasting—effects. H e a d Start is a very sensible p r o g r a m that o u g h t to m a k e a big d i f f e r e n c e — a n d it does a t f i r s t . Btit w h e n s t u d e n t s a r e l e f t i n p o o r f a m i l i e s , i n p o o r n e i g h b o r h o o d s , a n d in p o o r s c h o o l s , the H e a d Start g a i n s in IQ f a d e a n d the a c a d e m i c a c h i e v e m e n t e f f e c t s a r e n o t v e r y l a r g e . B u t t h e r e a r e prek i n d e r g a r t e n p r o g r a m s t h a t h a v e h u g e initial e f f e c t s o n I Q , a l o n g w i t h s i g n i f i c a n t r e s i d u a l e f f e c t s 011 I Q i f its g r a d u a t e s a t t e n d h i g h quality public schools. Even w h e n children are not in g o o d schools, the best p r o g r a m s nevertheless h a v e very large a c a d e m i c achievement effects a n d e n o r m o u s social benefits in terms of reduced crime a n d w e l f a r e dependence. Pre-kindergarten p r o g r a m s in general benefit p o o r kids a n d minority kids m o r e than better-off w h i t e kids. A similar pattern exists f o r e l e m e n t a r y and junior high school interventions.

I've described

many

p r o g r a m s that do not

have

Mind the

12 5

Gap

much effect on student achievement and therefore are unlikely t o b e a b l e t o c l o s e the racial a n d S E S g a p s . T h e f a c t o r s that d o m a k e a d i f f e r e n c e are the quality of the i n d i v i d u a l t e a c h e r , t e a c h e r incentives (probably, though much m o r e w o r k needs to be d o n e to find o u t just w h a t k i n d s o f incentive p r o g r a m s w o r k best a n d are m o s t practical), a n d class size ( w h i c h s e e m s to h a v e a bigger e f f e c t on black kids than on white kids). S o m e teaching techniques discussed in C h a p t e r 4 that are not terribly e x p e n s i v e are k n o w n to h a v e fairly sizable e f f e c t s and m i g h t help t o r e d u c e the a c h i e v e m e n t g a p . T h e s e include c o m p u t e r p r o g r a m s t o t e a c h m a t h a n d w r i t i n g ( w h i c h m i g h t a c t u a l l y b e less expensive than standard instructional methods) and " c o o p e r a t i v e l e a r n i n g " s i t u a t i o n s ( w h i c h w o u l d a d d little i f a n y t h i n g t o c o s t ) . Even if these techniques w e r e not f o u n d to reduce the g a p , the f a c t that they i m p r o v e the a c h i e v e m e n t of children in g e n e r a l indicates t h a t t h e y s h o u l d b e u s e d f o r e d u c a t i n g all k i n d s o f s t u d e n t s . A risi n g t i d e i s w e l c o m e e v e n i f i t l i f t s all b o a t s e q u a l l y . We k n o w that one math p r o g r a m — S E E D S — a n d one reading p r o g r a m — R e a d i n g R e c o v e r y — h a v e big effects on minority kids. R e a d i n g R e c o v e r y is particularly inexpensive a n d p r o v i d e s a big b a n g for the b u c k . A host of w h o l e - s c h o o l interventions h a v e been tried, a n d the results are m o s t l y d i s a p p o i n t i n g .

H o w e v e r , there is one hugely

important exception—the KIPP program.

Like Jaime Escalante,

K I P P teachers can get p o o r minority pupils to p e r f o r m at or a b o v e t h e level t y p i c a l o f w h i t e m i d d l e - c l a s s p u p i l s . A n d t h a t ' s t r u e e v e n w h e n they start the p r o g r a m late: s u r p r i s i n g l y , the e f f e c t s a r e big f o r students w h o start it in fifth g r a d e . It r e m a i n s to be seen w h a t KIPP could accomplish if it were to start with much y o u n g e r kids. Let's hope we find out soon.

Paying for

Gap

Reduction

But can we a f f o r d the effective p r o g r a m s ? A better question to ask is, c a n w e a f f o r d n o t t o h a v e t h e m ? M a n y e c o n o m i s t s h a v e e v a l u -

1150

INTELLIGENCE AND HOW TO GET IT

ated the benefit-cost ratio of the most successful pre-kindergarten interventions. The Nobel Prize—winning economist James Heckman estimates the payback of the Perry Preschool Program—in terms of special education classes avoided, extra years of schooling avoided, crime and welfare costs avoided, and higher incomes for its participants—to be eight to one. This is equivalent to a return on investment of 17 percent per year. And that is just the cold monetary calculation. The gains to participants' quality of life and those of their families and neighbors are not even included in those calculations. The initial cost of the Perry program is high—estimates range between $12,000 and $16,000 per student in 2.007 dollars. It is much more expensive than Head Start (though the costs of future Perry-type programs should be lower because there would be no research component, which was a significant part of the Perry program costs) but it would be vastly more effective. The same is true of the Abecedarian intervention, which has been calculated as having a benefit-cost ratio of $3.78 to the dollar. Even when benefits are calculated strictly to the taxpayer, in terms of education, welfare, and criminal justice charges saved, the costs of the most successful pre-kindergarten programs are repaid in time. So how much would it cost to enroll, say, the poorest third of children in a Perry or Abecedarian program from birth to the time of entry into kindergarten? There are about 7 million such children in the United States, and either the Perry or the Abecedarian program might cost as much as $15,000 per child per year. That works out to about $105 billion. But to soften the sticker shock, let me quickly point out that about $20 billion in public money is currently spent on pre-kindergarten programs. An unknown amount of privately spent money should also be subtracted. So should the additional earnings by the mother in the years during and after the program. The ultimate benefits to the child and to society should also be subtracted. Moreover, not nearly enough studies have been done on the most expensive programs—it is possible that very substantial improvements in

Mi fid the Gap

151

cognitive and social functioning could be achieved by spending n o t a b l y less t h a n $ 1 5 , 0 0 0 p e r c h i l d . F i n a l l y , recall t h a t g a i n s i n pre-kindergarten programs are proportional to need. T h e lower the m o t h e r ' s IQ a n d S E S , the g r e a t e r the g a i n s . So e v e n if we provide intensive pre-kindergarten to only the neediest one-sixth o r o n e - t w e l f t h o f the u n d e r - f i v e p o p u l a t i o n , the p a y o f f w o u l d b e very great. As a

yardstick

f o r m e a s u r i n g the g r o s s initial cost of early

c h i l d h o o d e d u c a t i o n , note that the projected p o s t - z o o i t a x cuts for the richest T

percent of U.S. families will cost the treasury

$ 9 4 billion in 2.009 a l o n e . H o w a b o u t the a p p a r e n t l y e x t r e m e l y e f f e c t i v e K I P P p r o g r a m s ? K I P P s c h o o l s are actually not m u c h m o r e e x p e n s i v e than the regul a r p u b l i c s c h o o l s . ( S o m e K I P P s c h o o l s c o s t less t h a n t h e p u b l i c s c h o o l s i n t h e i r d i s t r i c t s . ) B u t K I P P g e t s its r e s u l t s b y d i n t o f t h e w i l l i n g s l a v e l a b o r o f its y o u n g , i d e a l i s t i c t e a c h e r s w h o a r e p a i d only

slightly

more

than

public

school

teachers

of comparable

experience. A n d the K I P P teachers c a n n o t k e e p up the pace f o r many years. N o t surprisingly, unions have begun to o p p o s e K I P P schools f o r their rate-busting. H o w much w o u l d it cost to run K I P P schools if teachers w e r e paid the s a m e rate per h o u r that p u b l i c s c h o o l t e a c h e r s e a r n — which seems not only fair but necessary if sufficient teachers are to b e f o u n d ? K I P P students get a b o u t 6 0 percent m o r e c o n t a c t time with their teachers. M o s t of the c o s t of e d u c a t i o n is in the f o r m of physical plant, administrative and m a i n t e n a n c e costs, and interest on debt, which are not increased by K I P P techniques. T h e cost per pupil in the United States f o r the a v e r a g e p u b l i c school w a s a b o u t $ 8 , 0 0 0 in 2.005,

a n

d a b o u t a third of this is f o r teachers' p a y . If

we assume that teachers' pay w o u l d be 60 percent more, and if we a s s u m e that a

KIPP-type program w o u l d be made available

to one-third of the 40 million children five to f o u r t e e n y e a r s o l d , it w o u l d cost an extra $ 3 5 billion. But a g a i n , these costs w o u l d be offset to a significant degree by child-care costs saved plus additional e a r n i n g s b y the m o t h e r . T h e e c o n o m i c g a i n s o v e r the

INTELLIGENCE A N D HOW TO GET IT

1152

l i f e t i m e f o r c h i l d r e n in s u c h s c h o o l s c a n n o t be c a l c u l a t e d at this point. At a m i n i m u m they c o u l d be expected to d e f r a y a significant part of their extra cost. To be clear, I am not a d v o c a t i n g instituting particular p r o g r a m s at this time. A h u g e a m o u n t of research needs to be d o n e to establish w h e t h e r s o m e t h i n g l i k e t h e P e r r y o r M i l w a u k e e o r A b e c e d a r ian p r o g r a m w o u l d be e f f e c t i v e a n d feasible if scaled up to national p r o p o r t i o n s , a n d the s a m e thing is true of K I P P - t y p e p r o g r a m s . In the c a s e o f K I P P , w e w o u l d h a v e t o see h o w m u c h gain c o u l d b e e x p e c t e d f o r children of parents w h o did not exert e f f o r t to get their children into the p r o g r a m a n d k e e p them there. We have existence p r o o f s , h o w e v e r , that a m a r k e d reduction in the IQ a n d a c h i e v e m e n t g a p s is possible, a n d we k n o w that the costs of the e f f e c t i v e interventions a r e at least c o n c e i v a b l e . It w o u l d be irresponsible to fail to do the necessary research to find out w h a t kinds o f intensive p r o g r a m s d o the m o s t g o o d . F i n a l l y , if we w a n t to m a k e the p o o r smarter, a g o o d w a y to do it might be to m a k e them richer. T h e Scandinavian countries a r e m u c h m o r e e g a l i t a r i a n in their i n c o m e distribution than the United est a n d

States

is, a n d

the a c h i e v e m e n t g a p b e t w e e n their rich-

poorest children

reflects that

relative equality.

Honest

e m p l o y m e n t in a job having social value should pay enough to s u p p o r t a f a m i l y . T h i s c o u l d be a c h i e v e d in p a r t by i n c r e a s i n g the m i n i m u m w a g e ( w h i c h even w i t h the n e w increases will b e o n l y 7 3 percent o f w h a t i t w a s f o r t y y e a r s a g o ) , the E a r n e d I n c o m e T a x Credit, and child t a x credits. T h e e c o n o m i c cost o f a t least s o m e o f t h i s — a n d p r o b a b l y even m o r e than the c o s t — w o u l d be r e c o u p e d by increasing the p r o d u c tivity of the p o o r a n d reducing c r i m e a n d w e l f a r e rates. We w o u l d likely do well by d o i n g g o o d .

CHAPTER EIGHT

Advantage Asia? Good grief,

those scores are positively Asian.

— O n e Kuropean-American Silicon Valley high school senior to a n o t h e r , u p o n h e a r i n g a b o u t her e x t r e m e l y h i g h S A T scores

If there is no dark and dogged will, there will he no shining accomplishment; if there is no dull and determined effort, there will he no brilliant achievement. —Chinese saying

HERE A R E S O M E S T A T I S T I C S that should serve to concentrate the minds of people of European descent.

• in 1966, Chinese Americans who were seniors in high school were 67 percent more likely to take the SAT than were European Americans. Despite being much less highly selected, the Chinese Americans scored very close to European Americans on average. • In 1980—when they were thirty-two years old—the same Chinese Americans from the "class of ' 6 6 " were 62 percent more likely to be in professional, managerial, or technical fields than were European Americans. • In the late 1980s, the children of Indochinese boat people constituted 20 percent of the population of Garden Grove in Orange County, California, but claimed twelve of fourteen high school valedictorians. • In 1999, U.S. eighth-graders scored between .75 and 1.0 SD below Japan, Korea, China, Taiwan, Singapore, and Hong Kong in math and between .33 and .50 SD below those countries in science as indicated by the Third International Mathematics and Science Study. 153

INTELLIGENCE AND HOW TO GET IT

1154

• Although Asian Americans constitute only 2 percent of the population, all five of the Westinghouse Science Fair winners in 2008 were Asian Americans. • Asian and Asian American students now constitute 20 percent of students at Harvard and 45 percent at Berkeley. So European Americans might as well throw in the towel. Asians are just plain smarter. Actually, probably not. At least not as indicated by traditional IQ tests. Herrnstein and Murray, Rushton and Jensen, Philip Vernon, Richard Lynn, and others have reported that there are IQ differences favoring Asians, but Flynn has shown that such reports are due in good part to the failure of the researchers to report Asian IQs based on contemporary IQ test norms rather than on outmoded norms and to using small and unrepresentative samples. Basing scores on outmoded norms has the effect of erroneously raising Asian IQs. Flynn reviewed sixteen different studies, the results of which were fairly consistent with one another. Most showed that East Asians had slightly lower IQs than Americans. What is not in dispute is that Asian Americans achieve at a level far in excess of what their measured IQ suggests they would be likely to attain. Asian intellectual accomplishment is due more to sweat than to exceptional gray matter.

The

Asian

Drive for Achievement

Harold Stevenson and his coworkers studied the intellectual abilities and school achievement of children in three different cities chosen to be highly similar socioeconomically: Sendai in Japan, Taipei in Taiwan, and Minneapolis in the United States. They measured the intelligence and reading and math achievement of random samples of children in the first and fifth grades. We cannot know if the IQ tests really provided measures of intelligence that are fully comparable across the three populations (though the researchers believed they did—and make a pretty good case for

Advantage

Asia?

155

that). N e v e r t h e l e s s , in the first g r a d e , the A m e r i c a n s o u t p e r f o r m e d the J a p a n e s e

and

the

Chinese

on

most

intelligence tests.

The

a u t h o r s attributed this to the g r e a t e r e f f o r t of A m e r i c a n p a r e n t s to stimulate their p r e s c h o o l kids intellectually. W h a t e v e r the r e a s o n f o r the high A m e r i c a n p e r f o r m a n c e in the first g r a d e , by the fifth g r a d e the superiority o f A m e r i c a n children i n I Q w a s g o n e . F r o m these sets o f f a c t s w e learn that r e g a r d l e s s o f w h o w a s s m a r t e r than w h o m in the first g r a d e , the A m e r i c a n s had lost c o n s i d e r a b l e g r o u n d to the A s i a n children by the fifth g r a d e . But the truly r e m a r k a b l e f i n d i n g of this s t u d y w a s that m a t h a c h i e v e m e n t o f the A s i a n students w a s leagues b e y o n d that o f the U.S. students. T h e identical p r o b l e m s w e r e g i v e n t o J a p a n e s e , T a i w a n e s e , and A m e r i c a n children. B y the fifth g r a d e , T a i w a n e s e children scored a l m o s t i SD better in m a t h e m a t i c s than A m e r i c a n children, and the J a p a n e s e scored

1 . 3 0 S D s better than

Ameri-

can children. Even m o r e astonishing, in a m o r e extended study, S t e v e n s o n a n d his c o w o r k e r s l o o k e d a t the m a t h p e r f o r m a n c e o f fifth-graders in many different schools in China, T a i w a n , J a p a n , a n d the United States. T h e r e w a s n ' t a lot of d i f f e r e n c e a m o n g the A s i a n c o u n t r i e s . S c h o o l s i n all t h r e e c o u n t r i e s p e r f o r m e d a t a b o u t the s a m e level. T h e r e w a s m o r e v a r i a b i l i t y a m o n g the U . S . s c h o o l s . But the very best p e r f o r m a n c e by an A m e r i c a n s c h o o l w a s e q u a l to the w o r s t p e r f o r m a n c e of a n y of the A s i a n s c h o o l s ! IQ is not the point: s o m e t h i n g a b o u t A s i a n s c h o o l s or the m o t i vation of Asian children differs greatly f r o m A m e r i c a n schools or American children's motivation. Let's start with the schools. C h i l d r e n in J a p a n go to school a b o u t 2.40 d a y s a y e a r , w h e r e a s c h i l d r e n i n t h e U n i t e d S t a t e s g o to school about 1 8 0 days a year. T h e Asian schools are probably better, but the p e r f o r m a n c e of A s i a n A m e r i c a n children in U . S . s c h o o l s s h o w s that A s i a n m o t i v a t i o n c o u n t s f o r a n a w f u l lot. The

Coleman

report

on

educational

equality

in

the

United

States, p u b l i s h e d in 1 9 6 6 , m e a s u r e d the intelligence of a very large random sample of American children, and Flynn followed them until t h e y w e r e t h i r t y - s i x y e a r s o l d o n a v e r a g e . A m e r i c a n s o f E a s t

INTELLIGENCE AND HOW TO GET IT

1156

Asian descent scored about

1 0 0 o n the n o n v e r b a l portion o f I Q

tests a n d a b o u t 97 on the v e r b a l p o r t i o n , so they had a slightly lower overall IQ than did Americans of European descent. D e s p i t e t h e i r s l i g h t l y i n f e r i o r p e r f o r m a n c e o n I Q tests, t h e C h i n e s e A m e r i c a n s o f t h e c l a s s o f 1 9 6 6 w e r e a b o u t half a s l i k e l y a s other children to have to repeat a grade in K - 1 2 . F o r e s h a d o w i n g things t o c o m e , w h e n the C h i n e s e A m e r i c a n children w e r e c o m p a r e d with E u r o p e a n A m e r i c a n children in g r a d e s c h o o l , they did s l i g h t l y b e t t e r 011 a c h i e v e m e n t tests. B y t h e t i m e t h e y w e r e i n h i g h school, the Chinese A m e r i c a n s w e r e scoring one-third of a standard d e v i a t i o n h i g h e r t h a n E u r o p e a n A m e r i c a n s o n a c h i e v e m e n t tests. At a given IQ level, the C h i n e s e A m e r i c a n s p e r f o r m e d one-half of a s t a n d a r d d e v i a t i o n higher on typical a c h i e v e m e n t tests, c o m p a r e d with European Americans. T h e overachievement w a s particularly g r e a t o n m a t h e m a t i c s tests. I n tests o f c a l c u l u s a n d a n a l y t i c g e o m etry, the Chinese A m e r i c a n s surpassed E u r o p e a n A m e r i c a n s by a f u l l s t a n d a r d d e v i a t i o n . W h e n s t u d e n t s w e r e s e n i o r s i n high s c h o o l , the C h i n e s e A m e r i c a n s p e r f o r m e d a b o u t one-third of a standard d e v i a t i o n b e t t e r o n S A T tests t h a n d i d A m e r i c a n s o f t h e s a m e I Q . By

the

age

of thirty-two,

the

determination

of the

Chinese

A m e r i c a n s in the class of 1 9 6 6 had paid a d o u b l e d i v i d e n d . To get the e d u c a t i o n a l credentials to q u a l i f y f o r p r o f e s s i o n a l or technical or m a n a g e r i a l o c c u p a t i o n s , they needed a m i n i m u m IQ of 93, compared to

1 0 0 for whites. M o r e important, of those with

the IQ to q u a l i f y , f u l l y 78 percent h a d the persistence to get their credentials and enter those occupations c o m p a r e d to 60 percent of whites. T h e resulting total dividend w a s 55 percent of Chinese A m e r i c a n s in

high-status occupations, compared

to a third of

whites. T h e number for Japanese Americans w a s about h a l f w a y between the n u m b e r s for these t w o g r o u p s . F l y n n f o u n d s i m i l a r o v e r a c h i e v e m e n t r e l a t i v e t o I Q 011 a c h i e v e m e n t tests a n d in o c c u p a t i o n s in a w i d e variety of studies of E a s t Asians. Notice indicated

that

the

overachievement

by the m a r k e d d i f f e r e n c e

of

Asian

between

Americans,

measured

as

IQ and

Advantage Asia? academic

achievement,

157

is

sufficient

by

a c h i e v e m e n t tests such as those given

in

itself t o

establish

that

K—12 classrooms and

the S A T are n o t merely I Q tests b y a n o t h e r n a m e . T h e y m e a s u r e intellectual

achievement

as opposed

to

the

p o w e r of m e m o r y ,

p e r c e p t i o n , a n d r e a s o n i n g o f the kind t h a t I Q tests m e a s u r e . N o t e also that the o v e r a c h i e v e m e n t of A s i a n A m e r i c a n s establishes that a c a d e m i c a c h i e v e m e n t can be a better predictor of ultimate socioeconomic success than IQ. Recently, Flynn studied

the children of the m e m b e r s of that

original class of 1 9 6 6 . Since we k n o w that being raised in h o m e s of higher social class is associated with higher IQ, we w o u l d expect the children t o h a v e higher I Q s than n o t o n l y their o w n p a r e n t s but a l s o the p o p u l a t i o n a t large. A n d indeed they did. T h e m e a n o f the C h i n e s e A m e r i c a n c h i l d r e n w h e n they w e r e p r e s c h o o l e r s w a s 9 points higher t h a n the w h i t e a v e r a g e . B u t then m o s t w e n t to ordinary American schools, which we would expect would not be ideal f o r their intellectual d e v e l o p m e n t . In f a c t , the a v e r a g e of their I Q s steadily declined until it w a s o n l y 3 p o i n t s a b o v e the white mean by the time they w e r e adults. N o t i c e the a r b i t r a r i n e s s o f d e s c r i b i n g w h a t A s i a n s a c c o m p l i s h as o v e r a c h i e v e m e n t . I used the p h r a s e " A s i a n o v e r a c h i e v e m e n t " to a K o r e a n friend w h o had just spent a y e a r in the United States, w h e r e his c h i l d r e n a t t e n d e d p u b l i c s c h o o l s . " W h a t d o y o u m e a n by 'Asian overachievement'?," he expostulated. " Y o u should say 'American

underachievement'!"

He told

me that he w a s aston-

ished w h e n he a t t e n d e d c e r e m o n i e s at the e n d of the y e a r f o r his daughter's school and discovered that an a w a r d w a s given

for

h a v i n g d o n e all o f t h e h o m e w o r k a s s i g n m e n t s . H i s d a u g h t e r w a s o n e o f t w o recipients o f the a w a r d . T o h i m , g i v i n g a n a w a r d f o r doing homework was about as preposterous as giving an award for eating lunch. It is taken absolutely for granted by Asians. He i s r i g h t t o insist t h a t t h e p h e n o m e n o n i s o n e o f A m e r i c a n u n d e r a c h i e v e m e n t . It's quite r e a s o n a b l e to regard high a c h i e v e m e n t as the d e f a u l t state o f a f f a i r s a n d w h a t m o s t A m e r i c a n s d o a s s l a c k ing t o o n e d e g r e e o r a n o t h e r .

INTELLIGENCE AND HOW TO GET IT

1158

M y K o r e a n f r i e n d ' s b e m u s e m e n t t o u c h e s o n the key t o understanding Asian achievement magic. Asian and Asian A m e r i c a n achievement is not mysterious. It happens by w o r k i n g harder. J a p a n e s e high school students of the 1 9 8 0 s s t u d i e d 3V2 h o u r s a d a y , a n d t h a t n u m b e r i s l i k e l y t o b e , i f a n y t h i n g , higher t o d a y . T h e h i g h - s c h o o l - a g e children o f the I n d o c h i n e s e b o a t p e o p l e studied 3 h o u r s a d a y . A m e r i c a n high s c h o o l students in g e n e r a l s t u d y an a v e r a g e of 1 Vi h o u r s a d a y . (Black e i g h t h - g r a d e c h i l d r e n i n D e t r o i t s t u d y , o n a v e r a g e , z h o u r s p e r week. O f c o u r s e , at least s o m e of this failure to do h o m e w o r k w o u l d h a v e to be attributed to a school milieu that does not expect much.) There is also no mystery about why Asian and Asian American children w o r k h a r d e r . A s i a n s d o not need t o read this b o o k t o find out that intelligence a n d intellectual a c c o m p l i s h m e n t are highly m a l l e a b l e . C o n f u c i u s set t h i s m a t t e r s t r a i g h t t w e n t y - f i v e h u n d r e d years ago. He distinguished between t w o sources of ability, one by n a t u r e — a gift f r o m H e a v e n — a n d one by dint of hard w o r k . Asians

t o d a y still

believe

that

intellectual

accomplishment—

at a n y rate, d o i n g well in math in s c h o o l — i s primarily a matter o f hard w o r k , w h e r e a s E u r o p e a n A m e r i c a n s are m o r e likely t o believe it is m o s t l y a m a t t e r of innate ability or h a v i n g a g o o d teacher. A s i a n A m e r i c a n s h a v e attitudes on this topic that are in between those of East Asians and European Americans. Asians and Asian Americans have another motivational advantage

over

Westerners

and

Euiropean

Americans.

When

they do

b a d l y a t s o m e t h i n g , t h e y r e s p o n d b y w o r k i n g h a r d e r a t it. A t e a m of C a n a d i a n psychologists brought J a p a n e s e and C a n a d i a n college s t u d e n t s t o a l a b o r a t o r y a n d h a d t h e m w o r k o n c r e a t i v i t y tests. A f t e r t h e s t u d y p a r t i c i p a n t s h a d b e e n w o r k i n g 011 t h e m f o r a w h i l e , the r e s e a r c h e r s t h a n k e d t h e m a n d told t h e m a b o u t h o w well they did. R e g a r d l e s s of h o w well they had actually d o n e , the researchers told s o m e of the participants that they had d o n e very well and o t h e r s t h a t t h e y h a d d o n e r a t h e r b a d l y . T h e i n v e s t i g a t o r s then g a v e t h e p a r t i c i p a n t s a s i m i l a r c r e a t i v i t y test a n d t o l d t h e m t o s p e n d a s m u c h t i m e a s t h e y w a n t e d o n it. T h e C a n a d i a n s w o r k e d l o n g e r o n

Advantage

Asia?

159

t h e c r e a t i v i t y test i f t h e y h a d s u c c e e d e d o n t h e f i r s t o n e t h a n i f t h e y had d o n e b a d l y , but the J a p a n e s e w o r k e d l o n g e r o n the creativity test i f t h e y h a d f a i l e d o n t h e f i r s t o n e t h a n i f t h e y h a d s u c c e e d e d . Persistence in the f a c e of failure is very m u c h part of the A s i a n tradition of s e l f - i m p r o v e m e n t . A n d A s i a n s are a c c u s t o m e d to criticism in the service of s e l f - i m p r o v e m e n t in s i t u a t i o n s w h e r e W e s t e r n e r s a v o i d i t o r r e s e n t it. F o r e x a m p l e , J a p a n e s e s c h o o l t e a c h e r s a r e o b s e r v e d i n t h e i r c l a s s r o o m s f o r a t l e a s t ten y e a r s a f t e r t h e y begin teaching. T h e i r f e l l o w teachers give them f e e d b a c k a b o u t their teaching techniques. It is u n d e r s t o o d in J a p a n that y o u c a n not be a g o o d teacher w i t h o u t m a n y years of e x p e r i e n c e . In the United States, we tend to toss teachers into the c l a s s r o o m and a s s u m e they c a n do a g o o d j o b f r o m the g e t - g o . Or if n o t , it's because they haven't g o t w h a t it takes. B u t a still m o r e i m p o r t a n t r e a s o n f o r A s i a n s m a k i n g t h e m o s t of their natural

intelligence is that their c u l t u r e — a s channeled

t o t h e m b y t h e i r f a m i l i e s — d e m a n d s it. I n

the c a s e of C h i n e s e

culture, the e m p h a s i s on a c a d e m i c a c h i e v e m e n t h a s been present for m o r e than t w o thousand years.

A bright Chinese boy w h o

w o r k e d hard a n d did well o n the m a n d a r i n e x a m s c o u l d e x p e c t to elevate himself to a w e l l - p a y i n g high g o v e r n m e n t position. T h i s b r o u g h t h o n o r a n d w e a l t h t o his f a m i l y a n d his entire v i l l a g e — a n d t h e h o p e s a n d e x p e c t a t i o n s o f his f a m i l y a n d f e l l o w v i l l a g e r s w e r e w h a t m a d e him d o the w o r k . T h e r e w a s s u b s t a n t i a l u p w a r d mobility via e d u c a t i o n in C h i n a a c o u p l e of millennia b e f o r e this w a s the case in the W e s t . So Asian families are m o r e successful in getting their children to achieve academically because Asian families are more powerful agents of influence than are A m e r i c a n f a m i l i e s — a n d because w h a t they c h o o s e to e m p h a s i z e is a c a d e m i c a c h i e v e m e n t .

Eastern

Interdependence and

Western

Independence

Why should Asian families be such powerful agents of influence? H e r e I need to step b a c k a bit a n d note s o m e very g r e a t d i f f e r e n c e s

INTELLIGENCE AND HOW TO GET IT

1160

b e t w e e n A s i a n a n d W e s t e r n s o c i e t i e s . A s i a n s a r e m u c h m o r e interdependent and collectivist than Westerners, w h o are much more independent

and

individualist.

These

East-West

differences go

b a c k at least t w e n t y - f i v e h u n d r e d years to the time of C o n f u c i u s and the ancient G r e e k s . C o n f u c i u s e m p h a s i z e d strict o b s e r v a n c e o f p r o p e r role relations as the f o u n d a t i o n of society, the relations being primarily those of e m p e r o r to subject, husband to w i f e , parent to child, elder brother to younger brother, and friend to friend. Chinese society, which w a s t h e p r o t o t y p e o f all

East Asian societies, w a s an agrarian

one. In these societies, especially those that depend on irrigation, farmers need to get along with one another because cooperation is essential to e c o n o m i c activity. Such societies also tend to be very h i e r a r c h i c a l , w i t h a t r a d i t i o n o f p o w e r f l o w i n g f r o m the t o p t o the b o t t o m . Social b o n d s and constraints are strong. T h e linchpin of C h i n e s e society in particular is the e x t e n d e d f a m i l y unit. O b e d i e n c e t o t h e w i l l o f t h e e l d e r s w a s , a n d t o a s u b s t a n t i a l d e g r e e still is, a n i m p o r t a n t b o n d l i n k i n g p e o p l e t o o n e a n o t h e r . T h i s t r a d i t i o n a l r o l e o f t h e f a m i l y i s still a p o w e r f u l f a c t o r i n t h e relations of second- and even third-generation Asian Americans a n d t h e i r p a r e n t s . I h a v e h a d A s i a n A m e r i c a n s t u d e n t s tell m e t h a t they w o u l d like to go into p s y c h o l o g y or p h i l o s o p h y but that it is not possible because their parents w a n t them to be a d o c t o r or a n e n g i n e e r . F o r m y E u r o p e a n A m e r i c a n students, their p a r e n t s ' p r e f e r e n c e s f o r their o c c u p a t i o n s are a b o u t as relevant to them as their p a r e n t s ' taste in art. T h e G r e e k tradition g a v e rise to a f u n d a m e n t a l l y n e w t y p e of social relations. T h e e c o n o m y of G r e e c e w a s based not on largescale agricLiIture but on t r a d e , h u n t i n g , fishing, herding, p i r a c y , and small agribusiness enterprises such as viniculture and olive oil

production.

N o n e of these activities required close, f o r m a l -

ized r e l a t i o n s a m o n g p e o p l e . T h e G r e e k s , a s a c o n s e q u e n c e , w e r e independent a n d h a d the l u x u r y of being able to act w i t h o u t being b o u n d so m u c h by social c o n s t r a i n t s . T h e y h a d a lot of f r e e d o m to e x p r e s s their talents a n d satisfy their w a n t s . T h e individual

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161

personality w a s exalted and considered a proper object of c o m mentary and study.

Roman

society continued

the independent,

individualistic tradition of the G r e e k s , a n d a f t e r a

l o n g lull

in

w h i c h t h e E u r o p e a n p e a s a n t w a s p r o b a b l y little m o r e i n d i v i d u a l i s t t h a n his C h i n e s e c o u n t e r p a r t , t h e R e n a i s s a n c e a n d t h e n t h e I n d u s trial R e v o l u t i o n t o o k u p a g a i n t h e i n d i v i d u a l i s t s t r a i n o f W e s t e r n c u l t u r e a n d e v e n a c c e l e r a t e d it. It is hard for s o m e o n e steeped only in E u r o p e a n culture to c o m p r e h e n d the e x t e n t to w h i c h a c h i e v e m e n t in the E a s t is a f a m i l y a f f a i r and not primarily a matter of individual pride a n d status. Like

the

ancient candidate

for

mandarin

status,

one

achieves

because it is to the benefit of the f a m i l y — b o t h e c o n o m i c a l l y and socially. A l t h o u g h there m a y

be pride in personal

accomplish-

ment, a c h i e v e m e n t is not primarily a matter of enriching oneself or bringing honor to oneself. A n d — h e r e ' s the big a d v a n t a g e o f A s i a n c u l t u r e — a c h i e v e m e n t f o r the f a m i l y s e e m s to be a g r e a t e r g o a d to s u c c e s s t h a n a c h i e v e m e n t f o r the self. If I, as an i n d i v i d u a l W e s t e r n f r e e a g e n t , c h o o s e to achieve in order to bring myself honor or m o n e y , that is my decision. A n d if I decide that my talents are t o o m e a g e r or I d o n ' t w a n t to w o r k h a r d , I can c h o o s e to opt o u t of the rat race. But i f I a m l i n k e d b y s t r o n g b o n d s t o m y f a m i l y , a n d f e d its a c h i e v e ment demands along with my meals, I simply have no choice but to do my best in s c h o o l a n d in p r o f e s s i o n a l life t h e r e a f t e r . A n d the d e m a n d is reasonable because it has been m a d e clear to me that my a c h i e v e m e n t is a m a t t e r of will a n d not just innate talent. The achievement advantage of Asian Americans over European A m e r i c a n s is likely to increase. P r i o r to 1 9 6 8 , A s i a n i m m i g r a n t s to the U n i t e d S t a t e s w e r e p r o b a b l y n o t m o r e n a t i v e l y intelligent than their c o m p a t r i o t s w h o r e m a i n e d a t h o m e .

But the i m m i g r a t i o n

l a w s of the 1 9 6 0 s m a k e it relatively easy to c o m e to the United States for a person w h o is a professional a n d relatively hard for s o m e o n e w h o is not. T h e Asian A m e r i c a n n e w c o m e r s are going to have a cultural a d v a n t a g e over E u r o p e a n A m e r i c a n s in general because they are professional and m a n a g e r i a l types as well as being

INTELLIGENCE AND HOW TO GET IT

1162

East Asians. Both their social class and their culture are going to be favorable for the maximum development of educational and professional success of their children. And their children are going to have a genetic advantage as well because of the selection for talent. (This genetic advantage is likely to be slight. As we will see in the next chapter, environmental bottlenecks do not have much effect on the IQ of generations after the bottleneck.)

Holistic and Analytic

Habits

of Thought

The cultural differences of East and West result not just in quantitative differences in intellectual achievement but also in qualitative differences in habits of mind. Effective functioning for East Asians depends on integrating one's own desires and actions with those of others. Harmony has been the watchword for social relations for twenty-five hundred years in China. Effective functioning for Westerners is not so dependent on dealing with others. Westerners have the luxury of acting independently of the wishes of other people. These social differences have given rise to habits of mind on the part of Easterners that I describe as holistic. Easterners pay attention to a wide range of objects and events; they are concerned with relationships and similarities among those objects and events; and they reason using dialectical forms of thought, which includes finding the "middle w a y " between opposing ideas. Western perception and thought are analytic, which is to say that Westerners focus on a relatively small part of the environment, some object or person that they wish to influence in some way; they attend to the attributes of that small part with a view toward categorizing it and modeling its behavior; and they often reason using formal rules of logic. The need to attend to others means that the perception of Easterners is directed outward to a broad swath of the social environment and, as a consequence, to the physical environment as well. Takahiko Masuda and I showed people brief animated films of

Advantage

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163

u n d e r w a t e r s c e n e s a n d t h e n a s k e d t h e m t o tell u s w h a t t h e y h a d s e e n . T a k e a l o o k a t F i g u r e 8 . T , w h i c h s h o w s a still p h o t o t a k e n f r o m one of the films. T h e A m e r i c a n s f o c u s e d p r i m a r i l y on the most salient objects—large, rapidly m o v i n g fish, f o r e x a m p l e . A usual first response w o u l d be, "I s a w three big fish s w i m m i n g o f f t o the left; they h a d pink s p o t s o n their w h i t e b e l l i e s . "

Figure S.I. Still photo from a color animation Japanese and Americans who were asked to report From Masttda and Nishett (zooi).

film shown to what they saw.

T h e J a p a n e s e r e p o r t e d seeing m u c h m o r e o f the e n v i r o n m e n t — r o c k s , w e e d s , i n a n i m a t e c r e a t u r e s s u c h as snails. A t y p i c a l initial response w o u l d be, "I s a w w h a t l o o k e d like a s t r e a m ; the w a t e r w a s green; there w e r e r o c k s a n d shells o n the b o t t o m . " I n a d d i t i o n to p a y i n g attention to c o n t e x t , the J a p a n e s e n o t i c e d r e l a t i o n s h i p s between

the c o n t e x t a n d

p a r t i c u l a r o b j e c t s i n it. F o r e x a m p l e ,

they w e r e inclined to note that o n e object w a s n e x t to a n o t h e r or that a f r o g w a s c l i m b i n g on a plant. A l t o g e t h e r , the J a p a n e s e w e r e able t o report 6 0 percent m o r e details a b o u t the e n v i r o n m e n t than were Americans.

INTELLIGENCE AND HOW TO GET IT

1 164

In another study, M a s u d a demonstrated that when s h o w n cartoon pictures of a central figure flanked by other people and asked t o j u d g e the m o o d o f the central f i g u r e , the J a p a n e s e w e r e m u c h m o r e i n f l u e n c e d in their j u d g m e n t s by the e x p r e s s i o n s on the surr o u n d i n g faces than w e r e the A m e r i c a n s . A s i a n s a n d W e s t e r n e r s see different things

because they are

looking at different things. My c o w o r k e r s and 1 have rigged people up w i t h d e v i c e s that c a n m e a s u r e w h a t p a r t of a picture they are looking at every millisecond. Chinese spend more time looking a t the b a c k g r o u n d than d o A m e r i c a n s a n d m a k e m a n y m o r e e y e m o v e m e n t s back and forth between the m o s t salient object and the b a c k g r o u n d . T h e greater attention to context allows East Asians to make correct

judgments

about

Americans make mistakes. w h a t they call prone

to

causality Social

under

circumstances

"the fundamental attribution error."

overlook

important

where

psychologists have uncovered

social

and

situational

People are causes

of

b e h a v i o r a n d attribute the b e h a v i o r instead to w h a t they a s s u m e a r e a t t r i b u t e s o f the a c t o r — p e r s o n a l i t y traits, abilities, o r attitudes. F o r e x a m p l e , w h e n reading an essay that an instructor in a course or an experimenter in a psychology study has asked someone to write in f a v o r of capital punishment, Americans assume that the writer m u s t hold the view that he e x p r e s s e d . A n d they do this even w h e n the e x p e r i m e n t e r h a s just requested that they write an e s s a y u p h o l d i n g a v i e w the e x p e r i m e n t e r c h o s e . K o r e a n s in this situation correctly m a k e no a s s u m p t i o n that the person

whose

essay they read actually holds the position he takes in the essay. T h e greater attentiveness to c o n t e x t has been characteristic of E a s t A s i a n s since the time of the ancient C h i n e s e , w h o unders t o o d the c o n c e p t of action at a distance. T h i s m a d e it possible f o r them to u n d e r s t a n d the principles of m a g n e t i s m a n d acoustics a n d a l l o w e d them to f i g u r e o u t the true c a u s e f o r the tides (which escaped even Galileo). Aristotle's physics, in contrast, w a s comp l e t e l y f o c u s e d o n t h e p r o p e r t i e s o f o b j e c t s . I n his s y s t e m , a s t o n e fell t o t h e b o t t o m w h e n d r o p p e d i n w a t e r b e c a u s e i t h a d t h e p r o p -

Advantage

Asia?

165

erty of g r a v i t y , a n d a stick of w o o d f l o a t e d on the w a t e r b e c a u s e it h a d the p r o p e r t y of levity. T h e r e is no s u c h p r o p e r t y as levity, of c o u r s e , a n d g r a v i t y is not f o u n d in o b j e c t s but in the relation between objects. Despite the greater c o r r e c t n e s s of a n c i e n t C h i n e s e p h y s i c s , a n d despite the f a c t that C h i n a w a s leagues a h e a d of the G r e e k s in technological a c h i e v e m e n t s , it w a s the G r e e k s w h o invented formal science. T w o t h i n g s m a d e this p o s s i b l e f o r the G r e e k s . First, because the G r e e k s w e r e fixated on objects, they w e r e concerned

with

the attributes of o b j e c t s a n d

with

determining

the c a t e g o r i e s t o w h i c h they b e l o n g e d . I n o r d e r t o u n d e r s t a n d the behavior of objects, the G r e e k s invented g o v e r n e d the b e h a v i o r o f o b j e c t s .

And

rules that p r e s u m a b l y

rules a n d categories are

w h a t constitute science at base. W i t h o u t them, there can be no e x p l i c i t , g e n e r a l i z a b l e m o d e l s o f the w o r l d t o test. T h e r e c a n o n l y be technology, no matter h o w sophisticated. S e c o n d , the G r e e k s invented f o r m a l logic. As the story g o e s , Aristotle had gotten i m p a t i e n t w i t h h e a r i n g p o o r a r g u m e n t s in the m a r k e t p l a c e a n d the political a s s e m b l y a n d s o c a m e u p w i t h logic in o r d e r to rule o u t f o r m s of a r g u m e n t that are defective. In a n y case, logic d o e s in f a c t serve that f u n c t i o n in the W e s t . L o g i c w a s never of m u c h interest in C h i n a . In f a c t , it a p p e a r e d just o n c e , b r i e f l y , in the third c e n t u r y B C , a n d it w a s n e v e r f o r m a l ized. T h e G r e e k s c o u l d invent logic precisely b e c a u s e their h a b i t of argumentation w a s socially acceptable. In ancient C h i n a , and in most of East Asia today, disagreements are a risky b u s i n e s s — y o u might make an enemy if you contradict another person's point of v i e w . Instead of logic, the a b s t r a c t r e a s o n i n g patterns of the E a s t tend t o w a r d dialecticism, i n c l u d i n g a c o n c e r n

with

finding the

"middle w a y " between opposing arguments and an emphasis on integrating different points of view. Like rules, categories, and explicit models, f o r m a l logic is an e x t r e m e l y helpful tool f o r science. But the G r e e k s w e n t o v e r b o a r d in their f o n d n e s s f o r logical a r g u m e n t . T h e y rejected the c o n c e p t of zero because, they r e a s o n e d , zero w a s e q u i v a l e n t t o " n o n - b e i n g "

INTELLIGENCE AND HOW TO GET IT

1166

a n d n o n - b e i n g c a n n o t b e ! A n d Z e n o ' s f a m o u s p a r a d o x e s a r e the result of logic g o n e wild. (For e x a m p l e , m o t i o n is impossible. For a n a r r o w t o r e a c h a t a r g e t , i t w o u l d h a v e t o g o h a l f the d i s t a n c e b e t w e e n t h e b o w a n d t h e t a r g e t , then h a l f t h a t d i s t a n c e , a n d s o o n a d i n f i n i t u m , a n d t h u s c o u l d n e v e r r e a c h its t a r g e t . T h i s s t r i k e s u s a s c o m i c a l , b u t t h e G r e e k s t h o u g h t this w a s a real s t u m p e r . ) S o c i a l p r a c t i c e s a n d h a b i t s o f t h o u g h t t e n d t o get i n g r a i n e d , a n d so c o n t e m p o r a r y social and cognitive differences between East a n d W e s t a r e m u c h like those o f ancient times. T h u s w e might e x p e c t Westerners to be m o r e likely to e m p h a s i z e rules, categories, a n d logic, a n d E a s t e r n e r s to be m o r e likely to e m p h a s i z e relationships and dialectical reasoning. A n d , in fact, my c o w o r k e r s and I find this to be the case. When

we

presented

people

with

three

words

such

as

cow,

chicken, a n d grass, a n d a s k e d t h e m w h i c h t w o g o t o g e t h e r , w e g o t very different answers from Easterners and Westerners. Americ a n s w e r e m o r e l i k e l y t o s a y cow a n d chicken g o t o g e t h e r b e c a u s e t h e y a r e b o t h a n i m a l s ; t h a t is, t h e y b e l o n g t o t h e s a m e t a x o n o m i c category. Asians, however, focusing on relationships, were more l i k e l y t o s a y t h a t cow g o e s w i t h grass b e c a u s e a c o w e a t s g r a s s . We also presented syllogisms to Americans and

Asians and

a s k e d them to j u d g e the validity of their c o n c l u s i o n s . We f o u n d t h a t A s i a n s a r e j u s t a s g o o d a s A m e r i c a n s a t j u d g i n g the v a l i d i t y o f syllogisms that are stated in abstract t e r m s — a l l As are X, s o m e Bs a r e Y , a n d s o o n — b u t a r e l i k e l y t o b e led a s t r a y w h e n d e a l i n g w i t h f a m i l i a r content. Asians are inclined to judge conclusions that foll o w f r o m t h e i r p r e m i s e s t o b e i n v a l i d i f t h e y a r e i m p l a u s i b l e (e.g., All m a m m a l s hibernate/rabbits do not hibernate/rabbits are not m a m m a l s ) . A n d A s i a n s are likely to judge as valid conclusions that are in fact invalid but which are plausible. Finally, it is possible to s h o w that Americans sometimes m a k e m i s t a k e s in r e a s o n i n g o w i n g to the s a m e kind of " h y p e r l o g i c a l " stance that characterized the ancient G r e e k s . M y c o w o r k e r s and I s h o w e d that A m e r i c a n s will s o m e t i m e s judge a given plausible p r o p o s i t i o n to be m o r e l i k e l y to be t r u e if it is c o n t r a d i c t e d by a

Advantage

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167

less p l a u s i b l e p r o p o s i t i o n t h a n i f i t i s n o t c o n t r a d i c t e d . T h e A m e r i cans assume that if there is an a p p a r e n t contradiction between t w o p r o p o s i t i o n s , the m o r e p l a u s i b l e o n e m u s t b e true a n d the less p l a u s i b l e o n e m u s t b e f a l s e . A s i a n s m a k e t h e o p p o s i t e e r r o r o f judging a relatively implausible proposition to be m o r e likely to be true if it is c o n t r a d i c t e d by a m o r e p l a u s i b l e p r o p o s i t i o n t h a n if it is not c o n t r a d i c t e d — b e c a u s e they are m o t i v a t e d to find truth in both of t w o o p p o s i n g propositions. T h e s e p e r c e p t u a l a n d c o g n i t i v e d i f f e r e n c e s rest o n brain activity t h a t d i f f e r s b e t w e e n E a s t e r n e r s a n d W e s t e r n e r s . F o r e x a m p l e , when Chinese are s h o w n animated pictures of underwater scenes, a n area o f the brain k n o w n t o r e s p o n d t o b a c k g r o u n d s a n d c o n texts is m o r e active than it is for A m e r i c a n s . C o n v e r s e l y , an area o f t h e b r a i n k n o w n t o r e s p o n d t o s a l i e n t o b j e c t s i s less a c t i v e f o r Asians than

it is for Americans. A n o t h e r brain-function study

p u r s u e d the f a c t that A m e r i c a n s f i n d it easier to m a k e j u d g m e n t s a b o u t objects w h i l e ignoring their c o n t e x t s , a n d E a s t A s i a n s find it easier to m a k e judgments a b o u t objects w h i c h take into a c c o u n t their c o n t e x t .

Consistent with

this fact,

regions of the

frontal

and parietal cortices that are k n o w n to be involved in attention control are m o r e active w h e n a person m a k e s judgments of the n o n p r e f e r r e d , m o r e d i f f i c u l t k i n d — t h a t is, j u d g m e n t s t a k i n g i n t o account contexts for Americans and judgments that require ignoring c o n t e x t s f o r E a s t A s i a n s . H o w do

we

know

that

these

differences

in

perception

and

thought are social in origin and not genetic? T h e r e are t w o main reasons. First, in several of the studies we c o n d u c t e d , we c o m p a r e d A s i a n s , A s i a n A m e r i c a n s , a n d E u r o p e a n A m e r i c a n s . I n all the studies the A s i a n A m e r i c a n s perceived and r e a s o n e d in w a y s that w e r e intermediate b e t w e e n A s i a n s a n d Fluropean A m e r i c a n s , and were usually more similar to those of Fluropean Americans. Second, H o n g K o n g is k n o w n to be a

bicultural society, with

Chinese customs mingling with English ones. We found residents of H o n g K o n g to reason in a fashion intermediate between h o w Chinese and European Americans reason. And when H o n g K o n g

INTELLIGENCE AND HOW TO GET IT

1168

residents w e r e a s k e d to m a k e causal attributions a b o u t the behavior of fish, they r e a s o n e d like C h i n e s e a f t e r being s h o w n pictures such

as

temples

and

dragons

and

like

Westerners

after

being

s h o w n p i c t u r e s s u c h a s M i c k e y M o u s e a n d the U . S . C a p i t o l !

Eastern Engineers and

Western Scientists?

T h e different social inclinations and thought patterns of Easterners a n d W e s t e r n e r s h a v e i m p l i c a t i o n s f o r d o i n g well in engineering versus science. E v e r y o n e has heard the cliche that J a p a n e s e m a k e g o o d engineers but lag in science. T h i s

is no

mere stereotype. Japanese

p r o w e s s i n e n g i n e e r i n g i s the w o n d e r o f A m e r i c a n i n d u s t r y . A n d my colleagues w h o teach engineering and

m y friends w h o hire

e n g i n e e r s tell m e t h a t n o t o n l y a r e t h e r e m o r e A s i a n A m e r i c a n engineers

per capita

but they

also

make

better engineers than

European Americans on average. H o w e v e r , in the d e c a d e of the 1 9 9 0 s , f o r t y - f o u r N o b e l Prizes in science w e r e a w a r d e d to p e o p l e living in the United States, the great majority of w h o m w e r e A m e r i c a n s , and only one w a s a w a r d e d to a J a p a n e s e . T h i s is n o t entirely the result of a difference in funding. T h e J a p a n e s e have spent roughly 38 percent as m u c h o n b a s i c r e s e a r c h a s h a v e A m e r i c a n s o v e r the last t w e n t y five years, and they spend twice as m u c h as do G e r m a n s , w h o w o n five N o b e l Prizes i n the 1 9 9 0 s . C h i n a a n d K o r e a h a v e been relatively p o o r , d e v e l o p i n g c o u n t r i e s until recently, a n d it is t o o e a r l y t o tell h o w s u c c e s s f u l t h e i r c i t i z e n s w i l l b e i n b a s i c s c i e n c e . B u t it is p o s s i b l e to p o i n t to s o m e of the r o a d b l o c k s in the path t o s c i e n t i f i c p r o d u c t i v i t y t h a t m i g h t a p p l y t o all i n t e r d e p e n d e n t peoples w h o are inclined to be holistic thinkers. First, several social differences between East and West f a v o r Western progress in science. In J a p a n , which is m o r e hierarchically o r g a n i z e d t h a n the W e s t in m a n y respects, a n d w h i c h places a greater value on respect for elders, more research money goes to o l d e r , n o - l o n g e r - p r o d u c t i v e scientists. I believe that the p r e m i u m

Advantage on

Asia?

individual

169

achievement and

the

respect

for

personal

ambi-

tion in the W e s t f a v o r s scientific a c c o m p l i s h m e n t . L o n g h o u r s in the lab do not necessarily do m u c h f o r the scientist's f a m i l y , but they are essential to personal f a m e and glory. D e b a t e is taken for granted in the W e s t a n d is regarded as an essential part of the scientific enterprise, but it is c o n s i d e r e d r u d e in m u c h of the East. A J a p a n e s e scientist recently r e p o r t e d on his a m a z e m e n t at seeing A m e r i c a n scientists w h o w e r e friends sharply disagree with o n e a n o t h e r — a n d in public. "1 w o r k e d at the C a r n e g i e Institution in W a s h i n g t o n , and 1 k n e w t w o e m i n e n t scientists w h o w e r e g o o d friends, but o n c e it c a m e to their w o r k , they w o u l d h a v e severe debates, even in the journals. T h a t kind of thing h a p p e n s in the United States, but in J a p a n , n e v e r . " S e c o n d , the C o n f u c i a n

tradition, of which J a p a n

and

Korea

a r e a p a r t , h a s little u s e f o r t h e i d e a t h a t k n o w l e d g e i s v a l u a b l e f o r its o w n s a k e . T h i s s t a r k l y c o n t r a s t s w i t h t h e a n c i e n t G r e e k philosophical tradition, which prized such other

kinds.

(I

emphasize

the

k n o w l e d g e a b o v e all

t e r m philosophical tradition

in

the

p r e c e d i n g s e n t e n c e . T h e r e i s a n a m u s i n g p a s s a g e i n The Republic w h e r e a n A t h e n i a n b u s i n e s s m a n c a s t i g a t e s S o c r a t e s f o r his p u r s u i t of abstract k n o w l e d g e , telling him that a l t h o u g h it is a d m i t t e d l y a t t r a c t i v e in the y o u n g , it is d i s g u s t i n g in a g r o w n m a n . ) T h i r d , logic, the

intellectual tool

of debate,

is m o r e readily

applied to real-world content by Westerners than by Easterners. Even

the

occasional

hyperlogical

habits

of Westerners

can

be

useful in science, h o w e v e r c l u m s y and even c o m i c a l they can be in e v e r y d a y life. R e l a t e d to logic is the W e s t e r n t y p e of rhetoric found in formal discourse in science, l a w , and policy analysis. This consists of an overview of w h a t is being discussed, general c o n c e r n s a b o u t t h e t o p i c , s p e c i f i c h y p o t h e s i s , o p e r a t i o n s t o test the h y p o t h e s i s , discussion of pertinent f a c t s , d e f e n s e a g a i n s t possible c o u n t e r a r g u m e n t s , a n d

summary

of conclusions. Training

in this pattern of a r g u m e n t a t i o n b e g i n s in n u r s e r y s c h o o l : " T h i s t e d d y b e a r i s m y l o v e y , I l i k e h i m b e c a u s e . . . " P e r h a p s d u e t o its roots in debate and f o r m a l logic, the W e s t e r n f o r m of rhetoric is

INTELLIGENCE AND HOW TO GET IT

1170

not c o m m o n in the East. I find with my o w n East Asian students that the s t a n d a r d rhetorical f o r m is the last thing they learn on their w a y to a P h D . Finally, there is the matter of curiosity. For w h a t e v e r reason, Westerners seem to be m o r e curious than Easterners. It is Westerners w h o have e x p l o r e d the Earth a n d immersed themselves in science a n d w h o r e g a r d the p r o p e r s t u d y of p h i l o s o p h y to be the f u n d a m e n t a l n a t u r e o f h u m a n k i n d . I d o n o t k n o w w h y this should be, though I can speculate on o n e possible source. We k n o w that W e s t e r n e r s are c o n s t a n t l y b u i l d i n g c a u s a l m o d e l s of the w o r l d . In f a c t , the children of J a p a n e s e w h o are living in the United States for business reasons are often regarded by American teachers as h a v i n g w e a k p o w e r s o f a n a l y s i s b e c a u s e they d o not build such causal

models.

O n e consequence of building explicit models is

the e l e m e n t of surprise. T h e m o d e l s lead to p r e d i c t i o n s that turn out to be w r o n g . T h i s m a k e s a person eager to get m o r e accurate views—and more curious. N o n e of the

habits of mind

that are

more characteristic of

Easterners pose insurmountable obstacles to scientific excellence. T h e practice of science e n c o u r a g e s mental patterns 1 have labeled as Western a d v a n t a g e s , and the m o r e steeped in scientific culture that Easterners b e c o m e , the m o r e natural will scientific habits of m i n d b e c o m e . A n d E a s t e r n e r s m a y well b e a b l e t o s h a p e their distinctive habits of mind in w a y s that will provide a d v a n t a g e s for scientific i n q u i r y . Q u a n t u m t h e o r y in p h y s i c s rests on c o n t r a d i c tions that are a n a t h e m a to the W e s t e r n m i n d but c o n g e n i a l to the E a s t e r n m i n d . N i l s B o h r c r e d i t e d his d e e p k n o w l e d g e o f E a s t e r n p h i l o s o p h y w i t h his ability t o g e n e r a t e q u a n t u m h y p o t h e s e s . F o r the t i m e being. W e s t e r n e r s ' a d v a n t a g e in science m a y be t h e i r a c e i n t h e h o l e i n t h e i r f r i e n d l y c o m p e t i t i o n w i t h t h e Flast. But d o n ' t c o u n t on the a d v a n t a g e lasting f o r long. Until fairly f a r into the last c e n t u r y , E u r o p e a n scientists w e r e puzzled by the failure of A m e r i c a n s to p r o d u c e much science of note.

CHAPTER

NINE

People of the B o o k A man should sell all he possesses in order to marry the daughter of a scholar, as well as to marry his daughter to a —The Talmud:

scholar.

Pesahim 49a

IThe Jews/ are peculiarly and conspicuously the world's intellectual aristocracy.

— M a r k Twain,

in

a

letter w r i t t e n

in

1879

The United States today is the greatest fistic nation in the world, and a close examination of its 4.000 or more fighters shows that the cream of its talent is Jewish. — B o x i n g announcer Joe H u m p h r e y s i n

1930

IN AD 64, the J e w i s h h i g h p r i e s t Y e h o s h u a b e n G a m l a i s s u e d an e d i c t s p e c i f y i n g t h a t all m a l e s b e a b l e t o r e a d t h e T a l m u d . T h i s r e q u i r e m e n t w a s m e t w i t h i n a h u n d r e d y e a r s a f t e r its p r o m u l g a tion. T h e next national g r o u p to achieve universal m a l e literacy d i d n o t d o s o until a b o u t s e v e n t e e n h u n d r e d y e a r s l a t e r .

Jewish

Accomplishment

I t s c a r c e l y s e e m s c o i n c i d e n t a l t h a t the p e o p l e w h o f i r s t a c h i e v e d literacy should today be extraordinarily distinguished intellectually. Ashkenazi J e w s (those of E u r o p e a n descent) are overrepresented a m o n g N o b e l Prize w i n n e r s b y a f a c t o r r a n g i n g f r o m 5 0 t o 1 (the prize f o r p e a c e ) u p t o z o o t o 1 (the p r i z e f o r e c o n o m i c s ) i n r e l a tion t o the p e r c e n t a g e o f the w o r l d ' s p o p u l a t i o n t h a t i s J e w i s h , i t w o u l d be fairer, t h o u g h , to c o m p a r e the p r o p o r t i o n of J e w i s h prize w i n n e r s i n the W e s t e r n w o r l d , o r e v e n t h e U n i t e d S t a t e s . A m e r i c a n J e w s h a v e r e c e i v e d b e t w e e n 2.7 a n d 4 0 p e r c e n t o f all N o b e l Prizes i n s c i e n c e a w a r d e d t o A m e r i c a n s ( d e p e n d i n g o n w h e t h e r w e 171

INTELLIGENCE AND HOW TO GET IT

1172

count as Jewish only individuals w h o s e mothers and fathers are J e w i s h o r all w i n n e r s w i t h a t l e a s t o n e - h a l f J e w i s h h e r i t a g e ) . J e w s r e p r e s e n t less t h a n 2 . p e r c e n t o f t h e A m e r i c a n p o p u l a t i o n , s o this c o n s t i t u t e s an o v e r r e p r e s e n t a t i o n of a b o u t 1 5 to 1 (using the m o r e c o n s e r v a t i v e definition of w h o is J e w i s h ) . A p p r o x i m a t e l y the same o v e r r e p r e s e n t a t i o n applies t o A m e r i c a n w i n n e r s o f the A . M . T u r i n g A w a r d f o r c o n t r i b u t i o n s t o c o m p u t i n g . A n d 2.6 t o 3 4 p e r c e n t (depending on h o w we count w h o is J e w i s h ) of Fields M e d a l s in mathematics for Americans have gone to Jews. In the United States, J e w s c o m p r i s e 33 students,

an

approximately

equal

percent of Ivy League

percentage of the

faculty

at

elite c o l l e g e s , a n d a b o u t 3 0 p e r c e n t o f S u p r e m e C o u r t l a w c l e r k s . T h e s e a r e o v e r r e p r e s e n t a t i o n s by a f a c t o r of 1 5 or m o r e . J e w i s h achievement is According to

the

193 1

not limited to the purely intellectual. census of Poland, J e w s comprised

9.8

p e r c e n t o f t h e p o p u l a t i o n . J e w s , h o w e v e r , o w n e d 2.2..4 p e r c e n t o f the w e a l t h in the c o u n t r y . In the first f o u r years a f t e r W o r l d W a r I, m o r e than 70 percent of business licenses w e r e issued to J e w s . By

192.9, J e w s o w n e d 45 percent of large and medium-sized com-

mercial enterprises. By the mid to late industries

1 9 3 8 , the p r o p o r t i o n w a s 55 percent. By

1 9 3 0 s , a m a j o r i t y of the o w n e r s of the f o l l o w i n g

were Jews:

textiles,

chemicals,

food,

transportation,

building materials, and paper. So J e w s have proved to be extraordinarily successful in many e n d e a v o r s w h e r e intelligence is an a d v a n t a g e , including business and commerce.

Jewish

IQ

T h e stereotype of J e w s as

highly

intelligent,

then,

is certainly

b a c k e d u p b y t h e s t a t i s t i c s . I t i s a l s o b a c k e d u p b y I Q tests. J e w s h a v e the highest a v e r a g e I Q o f a n y ethnic g r o u p f o r w h i c h there are reliable d a t a . M o s t reports place the a v e r a g e A s h k e n a z i J e w i s h I Q a t t w o - t h i r d s t o o n e s t a n d a r d d e v i a t i o n a b o v e the w h i t e average. T h a t is equal to an IQ of 1 10 to 1 1 5 .

People of the The

Book

degree

of

173

overrepresentation

of

Jews

in

intellectual

realms is actually greater than w o u l d be e x p e c t e d on the basis of Jewish

IQ.

Let's

arbitrarily

specify

that an

IQ

of

1 4 0 or

a b o v e constitutes the a v e r a g e IQ at the m o s t s t r a t o s p h e r i c levels of intellectual

achievement—Nobel

Prizes and

the

like.

If we

assume an a v e r a g e IQ of 1 1 o for J e w s , J e w s w o u l d be expected to be overrepresented at IQ 1 4 0 by a factor of only 6 to 1. T h i s is s u b s t a n t i a l l y less t h a n the o v e r r e p r e s e n t a t i o n of at least x 5 to T that is a c t u a l l y f o u n d , a n d v e r y s u b s t a n t i a l l y less th an that if we count people with one Jewish parent. Even if we assume an average Jewish

IQ of

1 1 5 , the actual attainment is s o m e w h a t

greater than w o u l d be expected. We might also arbitrarily specify 1 3 0 as the a v e r a g e IQ of Ivy L e a g u e r s , p r o f e s s o r s at elite colleges, a n d S u p r e m e C o u r t l a w clerks. A s s u m i n g a n a v e r a g e I Q of 1 1 0 for J e w s , we would expect them to be overrepresented by a f a c t o r of 4, f a r less t h a n the a p p r o x i m a t e l y obtains.

Assuming an average IQ of 1 1 5

1 5 to

1

that

for Jews, we would

expect J e w s to be overrepresented at IQ 1 3 0 by a factor of only a b o u t 7 to 1, a g a i n s u b s t a n t i a l l y less than the a c t u a l r a t i o . If we take these n u m b e r s s e r i o u s l y — a n d I actually r e c o m m e n d taking them with m o r e than a grain of salt as w e l l — t h e n J e w s are not only extraordinarily high achievers, they reach

the

heights in

good part by overachieving. It is i m p o r t a n t to note that the a v e r a g e IQ of S e p h a r d i c (mostly North African) J e w s is apparently no higher than that of n o n - J e w s and is considerably l o w e r than that of A s h k e n a z i J e w s . T h i s is true even of Sephardic and Oriental J e w s in Israel.

In Their Genes f D o e s the very large d i f f e r e n c e in IQ a n d intellectual a c c o m p l i s h ment between Ashkenazi J e w s and non-Jewish Westerners require a genetic e x p l a n a t i o n ? T h e r e is certainly no dearth of such e x p l a nations f o r the J e w i s h intelligence a d v a n t a g e . H e r e I m e n t i o n just five o f the m o s t f r e q u e n t l y i n v o k e d e x p l a n a t i o n s .

1174

INTELLIGENCE AND HOW TO GET IT

1. Persecution's bounty. One very old genetic explanation is that the persecution of European Jews hit hardest at the less intelligent, w h o were presumably less clever at escaping the enemy. The result of trimming disproportionately the least intelligent Jews from the gene pool was to shift ever upward the average intelligence of the remaining members of the group. There are two problems with this explanation. First, it is far from clear that it was the least intelligent Jews w h o were most likely to be killed by pogroms. We can as convincingly argue that the most economically successful and intelligent would have been particularly conspicuous and likely to be attacked. Second, it is not clear that disproportionate elimination of the less intelligent from the gene pool would have had much effect. The phenomenon presumed by this explanation is what is known as a genetic "bottleneck"—the result of trimming some genotypes from the breeding population because of an unusual environmental circumstance. (The classic example of a bottleneck is when a small portion of a breeding population in a particular region moves away from that region, bringing with it only a limited portion of the original genetic variation.) Bottleneck effects, however, could not plausibly account for much in the way of elevated IQ for Jews, even under the assumption of very high heritability of I Q . Complete elimination from reproduction of the lowest i 5 percent of the IQ distribution would raise the average IQ of the subsequent generation by about i point. There would have had to have been very thorough elimination of large numbers of people in the lower reaches of the gene pool, over many different occasions, to make much of a genetic difference. 2. Nebuchadnezzar's favor. The geneticist Cyril Darlington has proposed that the Babylonian captivity of the Jews led to their intellectual enhancement. Jerusalem fell in 5 8 6 BC, and according to the Bible, Nebuchadnezzar "carried into exile all Jerusalem: all the officers and fighting men, and all the craftsmen and artisans . . . Only the poorest people of the land were left" (2 Kings 24:10). This hypothesis further specifies that the relatively

People of the

Book

175

unintelligent Jews who were left behind would have drifted into other religions, so that when the Jews returned to the Holy Land, they would not have had further interaction with the unintelligent individuals left behind. Aside from the stipulation that the unintelligent Jews drifted away from their religion, which is highly speculative, the theory rests on a hypothesis of a single bottleneck. Even under the assumption of very high heritability of intelligence and under the further, dubious, assumption that intelligence would have been highly correlated with wealth status in ancient times, the trimming off of a very substantial fraction of the poorest people from the breeding population would have left the next generation very little less intelligent than the previous generation. 3. Marry the scholar. Another popular genetic theory is that the daughters of (highly intelligent) merchants and businessmen were likely to be married off to the (highly intelligent) scholar or rabbi. The fruits of such unions would have been better off financially, and their offspring would have been more likely to survive. Adherents to this theory sometimes point to the injunction in the Talmud to marry a scholar. But arguments have been made that Jews both rich and poor were reluctant to entrust their daughters to penniless scholars, and the rich would have preferred a businessman. Moreover, the number of individuals involved in the presumably IQ-beneficial unions would have been a small fraction of the total population, making it dubious that they could have elevated the population average much at all. 4. Talmud dropouts. Political scientist Charles Murray has proposed that mere literacy would not have been sufficient to satisfy the requirement of being able to read a difficult text—the Talmud—and comprehend it, let alone provide an exegesis. Those who were unable to function at such a high level of literacy would have drifted away from the group, leaving behind only the most intelligent to propagate future generations. Murray's theory is interesting, but nothing more than speculation.

1 76

INTELLIGENCE AND HOW TO GET IT

5. Occupational pressure. Anthropologists Gregory Cochran, Jason Hardy, and Henry Harpending have proposed by far the most elaborate theory of inherited Ashkenazi Jewish intelligence. The Ashkenazim enter the historical record of Europe in about the ninth century. From a very early point they were engaged in occupations requiring literacy, numeracy, and generally high intelligence, including money lending (forbidden to Christians because of usury laws), trading, and—especially in Eastern Europe— tax-farming and estate management. These occupations brought wealth to those who could handle them. Wealth meant greater survival of offspring. Hence more intelligent people had more offspring than less intelligent people, and the average intelligence of the population slowly increased. Cochran and his colleagues propose a specific mechanism underlying increased Ashkenazi intelligence. Their account begins with the fact that Ashkenazim have a particular propensity to illnesses involving storage in the nerve cells of so-called sphingolipids, which form part of the insulating outer sheaths that allow nerve cells to transmit electrical signals and encourage growth of dendrites. These illnesses include Tay-Sachs, Niemann-Pick, and Gaucher's disease. Storing too much of these sphingolipids is fatal or at least likely to result in a serious illness that often prevents reproduction. But why should an increase in sphingolipids result in higher intelligence for the nondiseased portion of the population? At this point, Cochran's group enlists the sickle-cell anemia analogy. The sickle-cell gene produces illness for individuals who have two copies of it (one from each parent). But those with only one copy of the gene are provided with protection against malaria. This is useful for West Africans, who are threatened in their natural habitat by malaria and are by far the most likely people in the world to have the sickle-cell gene. The proposed analogy to high intelligence for the Ashkenazim is that two copies of the extra-sphingolipid gene result in serious illness or death, but one copy of it results in high but nonlethal

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levels of sphingolipids. And high levels of sphingolipids encourage transmission of nerve signals and increased growth of dendrites. Presumably more expansive branching of these neuron extensions favors learning and general intelligence. Apparently sphingolipids do facilitate nerve transmission and encourage neural branching. But otherwise the only evidence for the sphingolipid theory is that people with Gaucher's disease are highly intelligent even as compared with other Jews. Gaucher's victims in Israel have unusually high occupational status on average, and there are as many physicists among Gaucher's patients as there are skilled workers. The sphingolipid theory modeled on the sickle-cell analogy does have one virtue over the other speculations about the genetic superiority for Ashkenazi Jews. It makes the clear prediction that people who have only one copy of the extra-sphingolipid gene should have higher IQs than those who have no copy of the gene. However, Cochran and colleagues did not test this prediction, other than reporting impressive occupational attainment for Gaucher's victims. I find this puzzling. The hypothesis is not hard to test, and many scientists would have tested this prediction before publishing a complicated theory. Note that the Cochran theory has an unusual property in that it attributes no great causal significance to the fact that the Jews had universal literacy at such an early stage in history. Literacy was important only insofar as it made it easier for the Jews to engage in the occupations that ultimately produced high intelligence for the group. Indeed, it is important to the Cochran theory that there not be much Jewish intellectual accomplishment prior to the time that occupational advantages began to work their genetic magic. And it is certainly true that intellectual accomplishments of a high order by Ashkenazi Jews came with ever greater frequency over the centuries, reaching a crescendo by the middle of the nineteenth century. It is also important to the Cochran theory that Sephardic Jews not be terribly accomplished, since they did not pass through the

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INTELLIGENCE AND HOW TO GET IT

genetic filter of occupations that demanded high intelligence. Contemporary Sephardic Jews in fact do not seem to have unusually high IQs. But Sephardic Jews under Islam achieved at very high levels. Fifteen percent of all scientists in the period AD 1150—1300 were Jewish—far out of proportion to their presence in the world population, or even the population of the Islamic world—and these scientists were overwhelmingly Sephardic. Cochran and company are left with only a cultural explanation of this Sephardic efflorescence, and it is not congenial to their genetic theory of Jewish intelligence. In short, there are many genetic theories of Jewish intelligence but not much in the way of convincing evidence.

Other Cultures ivith High Levels of Intellectual Accomplishment Jewish intellectual eminence needs to be put into context with the fact that intellectual achievements have often differed hugely between cultures—even between cultures with high rates of literacy and robust economies. And it is impossible to give a genetic account to these fluctuating rates of accomplishment. In AD l o o o , the intelligentsia of the world consisted primarily of Arabs and Chinese. Arab sheiks were discussing Plato and Aristotle, and Chinese mandarins were practicing all the arts, at a time when European nobles were gnawing haunches of meat in cold, dank castles. The intellectual scoreboard was lit up for Chinese and Arabs (and Indians) when the tally was near zero for Europe. Then Europe gradually came to intellectual preeminence, partly because of its willingness to learn from the more advanced cultures. Changes in the gene pool are an impossible explanation for this enormous shift in the intellectual center of gravity. Even within Europe the swings of intellectual prominence have been extraordinarily wide. Spain was at the height of intellectual achievement under the Moors, but sank rapidly thereafter, never

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achieving much of great note even in the heady days of N e w World gold and silver. Northern Italy was a powerhouse in all the arts and sciences in the fifteenth century, a time when England was a cultural backwater. Since 1800, England has been a leader in almost all realms of endeavor and a lion in science, philosophy, and literature. Italy since 1800 has been a shadow of its Roman and Renaissance self. The Scots, well past the late Middle Ages, were savages painting themselves blue for battles and frequently choosing leaders by means of assassination. (Shakespeare had good reason to site Macbeth in Scotland.) By the eighteenth century, the Scots were leaders in science and philosophy. Scandinavia was not noted for intellectual achievements until the twentieth century. Within the United States, the regional differences in intellectual accomplishment have been nothing shy of astonishing. The Northeast has never had much more population than the South, but easterners have achieved incomparably more in science, philosophy, and the arts (save for music) than have southerners. The population of Texas has exceeded that of N e w England for the last hundred years by a factor of 3 or 4; even the white, non-Hispanic population of Texas is larger than that of N e w England. But a visit to Who's Who establishes that Texans have achieved virtually nothing in the sciences or philosophy (though there have been notable achievements in literature, music, and the arts in recent decades). The magnitude of the differences in intellectual accomplishment between Jews and non-Jews in the West pales beside all these national, ethnic, and regional differences. This still leaves us, however, with the differences in IQ between Jews and non-Jews. Can this plausibly be accounted for exclusively by cultural factors?

Cultural

Explanations

of Jewish

Intelligence

Education has been as important to the Jewish tradition as to the Confucian tradition. As Austrian novelist Stefan Z w e i g wrote during World War II, "It is counted a title of honour for the entire

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INTELLIGENCE AND HOW TO GET IT

family to have someone in their midst, a professor, a savant, or a musician, who plays a role in the intellectual world, as if through his achievements he ennobled them all." The analogy between Jews and Confucians is marked in another crucial respect as well. Family ties are very strong for Jews, and the family can make demands on the individual that are hard to resist. The Jewish mother, fabled in song and story, is reputed to have an influence that seems equal to that of any Chinese patriarch. And much of her influence is directed toward educational and intellectual attainment. The Jewish value of education takes some forms that seem extreme to non-Jews. Psychologist Seymour Sarason was raised in a poor neighborhood, and his family never had money. But Sarason reports that when one of his cousins decided to play football in high school, the family was angry and disbelieving. If he got injured, the family worried, he might not be able to go to college. (Compare with Friday Night Lights.) Sarason also recounts that his father, who had little money and less education, once bought an expensive encyclopedic dictionary for the family. This made a huge impression on Sarason. It told him that education was important—even at great financial sacrifice. In Brooklyn today, while other boys trade baseball cards, Hasidic boys trade rabbi cards. And so on and so forth. It would be possible to list numberless anecdotes showing that Jews value intelligence, the intellectual life, and achievement. The value on achievement is certainly not limited to intellectual fields. In addition to business success, Jews in the past have valued athletic success. In the early part of the past century, high achievement included preeminence in boxing, wrestling, and basketball (which one anti-Semitic commentator claimed was the quintessential Jewish sport—because it involved sneakily stealing the ball). So it seems that Jews place a high value on achievement, period. But the sum of evidence about the cultural value placed on intellectual achievement would amount to only a pile of anecdotes. We

People

of the

Book

181

have no quantifiable measure of cultural influences on intellectual achievement, not even systematic anthropological observations of the kind that Shirley Brice Heath made comparing middle-class whites, working-class whites, and poor blacks. We can, however, speculate that culture has resulted in an increase for Jews in phenotypic IQ. (This is the IQ that the individual has as a consequence of the environment operating on the individual's genetic makeup in a particular way.) Recall that the children of the Chinese American members of the class of 1966, who were themselves of average or slightly less than average IQ but attained very high occupational status, had IQs averaging 109 when they were quite young. That was before these children encountered the U.S. public school system and engaged with the non-Asians in their neighborhoods. By late childhood the average IQ of the children of the class of '66 had dropped to 103. But the grandchildren of the class of '66 would have an advantage even over the children of the class of '66 because the children of the class of '66 had higher (phenotypic) IQs than their parents and thus would likely have created yet more advantaged environments. The consequence is that the IQ of the grandchildren of the Asian American class of '66 might well be greater than 103. The Asian American example of one generation building IQ on the socioeconomically advanced shoulders of the preceding generation shows that culture could account for a significant portion of the IQ gap between Jews and non-Jews—perhaps even all of it—by scaffolding to ever higher levels. In any event, Jewish intellectual achievement is probably at least in part overachievement. Achievement at such ultrahigh levels seems substantially greater than would be predicted by the IQ advantage.

CHAPTER TEN

Raising Y o u r Child's Intelligence . . . a n d Your Own

I remind you of some things you already know about how to increase the intelligence of your child and yourself, point out some things that you may believe to be true but for which there is little evidence, and describe some ways to increase intelligence that may be surprising to you. By i?itelligence> I mean ability to solve problems and to reason, which is measured, if only imperfectly, by IQ scores and academic achievement. IN THIS C H A P T E R

The

Obvious

First, the things you probably do instinctively with your child, without much conscious consideration of strategy, can increase intelligence: Talk to your child, using high-level vocabulary. Include your child in adult conversations. Read to your child. M i n i m i z e reprimands and maximize comments that will encourage your child to explore the environment. A v o i d undue stress, which you would do anyway, but probably not for the reasons given in this book. Stress can result in poor learning ability and ability to solve novel problems as it can damage pathways between

1X2

Raising Your Child's Intelligence . . . and Your Oivn

183

the limbic lobe and the prefrontal cortex. At extremes, stress can interfere with memory capacity as well. Teach your child how to categorize objects and events and h o w to make comparisons among them. Encourage your child to analyze and evaluate interesting aspects of the world. Give your child intellectually stimulating after-school and summertime activities. (Though I have to admit that I do think some parents overprogram their kids. The forced suburban march from hockey practice to piano class to Cub Scout meetings is not something I would personally recommend.) T r y to steer your child toward peers w h o will promote intellectual interests. These are the sorts of things that people of higher socioeconomic status (SEvS) are more likely to do than people of lower SES, and they are all correlated with children's ultimate intelligence. Admittedly though, the data are just that—correlational—for the most part. We do not know the extent to which activities like these cause greater intelligence as opposed to just being the sorts of activities that smarter parents carry out with their children— who are destined to be smarter than average because of their parents' good genes and not their exemplary behavior. On the other hand, common sense indicates that these things ought to be beneficial and it's hard to see how they could do harm. And we do know that when poor children are raised by higher-SES parents, who are inclined to do these things, the children end up having higher IQs and better academic performance.

The

Dubious

Despite what you may have heard bandied about in the press, some things do not affect intelligence much—or at any rate there is not very good evidence that they do. Baby Einstein educational toys that move around and communicate with the child may be as likely to induce passivity as to encourage exploration. There is no evidence that playing M o z a r t to your child—whether born yet or

INTELLIGENCE AND HOW TO GET IT

1184

not—will increase intelligence. The research suggesting that extra stimulation in the early years results in more growth of neurons and better problem-solving ability is based strictly on animal studies comparing rats that had absolute minimal stimulation—sitting in the dark in small cages—with animals that were allowed to play in interesting environments and given a companion to do it with. We find the same kind of huge gains with infants who are drastically understimulated and then brought into normal environments. We do not know whether stimulation at unusually high levels using fancy toys does much for human infants. But lots of other things do seem to matter, and for many of them we have very good evidence about their usefulness.

The

Physical

Bigger babies grow tip to be smarter adults than do smaller babies. We do not know whether size at birth causes higher intelligence or is merely correlated with it. But why take a chance when there is something you can do to increase the size of the baby? Namely, exercise. W o m e n who exercise on a treadmill twenty minutes a day a few times a week have bigger babies, and bigger babies are certainly healthier and may well grow up to be smarter because of some variable associated with their size. That variable could be brain size. The babies born to exercising mothers have larger heads. We know that people with larger brains are more intelligent on average. Exercise is good for the baby, for mothers-to-be, and for everybody else. Exercising large muscle groups actually increases growth of neurons, and exercise, at least in animals, adds to the blood supply of the brain. Even introducing exercise relatively late in life is good for intelligence. Experiments show that elderly people who are encouraged to exercise maintain good problemsolving skills longer than people who are not encouraged to exercise. The effect of exercising thirty minutes or more per day on fluid intelligence—based tasks is .50 SD across all studies. Strength

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185

training plus cardiac training is better than cardiac training alone. People who exercise regularly in middle age are one-third as likely to get Alzheimer's disease in their seventies as people who do not exercise. You can even start exercise in your sixties and reduce the likelihood of Alzheimer's by half. A possibly very important thing a mother can do for her child's intelligence is to breast-feed. For children with the most common kinds of genetic makeup, breast-feeding for up to nine months may increase IQ as much as 6 points. (Breast-feeding beyond nine months seems to have no beneficial effect.) It seems to be particularly important to breast-feed premature babies.

Fluid-Intelligence

Exercises

Several types of activities can improve fluid intelligence, and not just for children. Recall that fluid intelligence is the ability to solve problems that are novel and for which previously learned rules or concepts are not necessarily helpful. The prototypical example is the Raven Progressive Matrices test. You see various geometric figures that have been changed in particular ways and you have to develop on the spot a rule that will allow you to determine what the next transformation of the figures should be. The activities that increase fluid intelligence include computer games that teach attention control and exercise working-memory capacity. Neuroscientist Rosario Rueda and her colleagues described several types of games that exercise fluid-intelligence functions for young children. One was anticipation exercises. An exercise they used for this involved teaching children to anticipate where a duck that had submerged itself in a pond would emerge. The children used a joystick to manipulate a cat to the position where they expected the duck to turn up. Another exercise involved stimulus discrimination. Children had to remember the attributes of cartoon portraits so that they could pick the portrait out of an array of several other portraits. Other tasks, described in Chapter 3, included a conflict-resolution exercise and an inhibitory-control

1 186

INTELLIGENCE AND HOW TO GET IT

exercise. These exercises improved performance on the Raven Progressive Matrices test, which makes heavy demands on attention control and working memory. These fluid-intelligence functions are particularly important for children's learning in the years before adolescence. For a demonstration of these exercises, go to http://www.teach-the-brain.org/Iearn/attention/index.htm Child neurologist Torkel Klingberg and his coworkers found that various w o r k i n g - m e m o r y and attention-control tasks improved the concentration of children with attention deficit hyperactivity disorder ( A D H D ) . Some of these tasks are easy to duplicate without using a computer. For example, experimenters read to children a series of digits (perhaps 4, 7, zy 5) and then ask them to repeat the digits back in the reverse order in which they were read. Other tasks require computer administration, such as a "go—no g o " task in which the child is shown t w o gray circles and has to press a key if a circle turns green and refrain from pressing it when it becomes red. Such exercises improved reaction times and reduced errors even on tasks for which the children had not been trained, and improved scores on the Raven IQ test. T h e Raven scores for almost all the trained children exceeded the average for the untrained children. Similar exercises improved working memory and Raven performance in normal, healthy adults. Finally, meditation exercises typical of the kind used in Chinese traditional medicine (breathing exercises, postural training, body awareness) conducted over a period of just five days improved executive functioning and performance on Raven Progressive Matrices. If this seems dubious to you, it would to me too, except that the authors of the study include highly respected neuroscientists Yi-Yuan Tang and Michael Posner, so I believe it.

Self-Control The best evidence we have indicates that children with aboveaverage self-control have higher intelligence, and higher academic

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achievement whatever their level of intelligence. Personality psychologist Walter Mischel and his colleagues found that the largely upper-middle-class children at Stanford University's nursery school who could delay gratification in the here and now (one cookie) for better rewards later ( t w o cookies) got higher grades and substantially higher S A T scores when they were teenagers. Lower-SES minority children in N e w Y o r k also got higher grades if they had greater ability to delay gratification. We do not know, however, whether the ability to delay gratification is associated with later scores on ability tests merely because children with more intelligence at age four incidentally happen to have better ability to delay gratification, and then become smarter teenagers not because their ability to delay gratification helped them to learn but because they were destined to be smarter owing to other inherited or environmental reasons. But it does seem likely that the ability to delay gratification in itself increases ability because greater self-control makes studying easier. Recall that psychologists Angela Duckworth and Martin Seligman found that junior high school students in a magnet school in Philadelphia who had greater self-control had higher grade point averages. In fact, the correlation between self-control and grade point average was twice as great as the correlation between IQ and grade point average. Here we are on safer causal ground. Self-control almost surely contributes to achievement over and above the intelligence level that a person happens to have. Unfortunately, we are not confident about knowing ways to increase self-control in children, but the research provides some hints. We do know that if children watch adults who reward themselves regardless of their performance, they are more likely to do the same for themselves. But if they watch adults reward themselves only for high-quality performance, children do that themselves. Also, Mischel and his coworkers had a few tricks that helped the children in their study to delay consuming a goodie immediately as opposed to waiting for a bigger reward.

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INTELLIGENCE AND HOW TO GET IT

When researchers had the children "think fun thoughts" instead of thinking about the rewards, the children were able to delay longer. When researchers encouraged them to put the rewards away, out of their line of sight, they also delayed longer. We do not know whether these kinds of suggestions would generalize to behavior outside the lab session where they were tatight, but they might. And if parents were to look for occasions to encourage children to be patient, and especially if they gave suggestions about how to be patient, this might be effective. Parents might also try modeling delay of gratification. MischePs group found that children behaved like the adults they watched. Some children saw an adult take an immediate reward instead of waiting for a larger one later. The adult said things like, " Y o u probably have noticed that I am a person who likes things now. One can spend so much time in life waiting that one never gets around to really living." Even children who were inclined to delay gratification, but who watched such a model, subsequently took the immediate reward most of the times they were offered it.

Teach Malleability—and Praise Children for Hard Work It is crucial for parents to teach children that their intelligence is under their control. Asians are particularly likely to believe that ability is something you have to work for. N o t surprisingly, Asian Americans work harder to achieve academic goals than European Americans. And Asians work harder after failure than after sticcess—unlike North Americans of Etiropean descent w h o work harder after success than after failure. It is important to teach children that if at first you don't succeed, try again harder. It is probably a bad idea to praise children for being intelligent. Instead, praise hard work, which is under their direct control. The problem with praising children for their intelligence is that it makes them focus on trying to show how smart they are by

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w o r k i n g on tasks they do well on and a v o i d i n g w o r k i n g on tasks they are h a v i n g t r o u b l e w i t h . W h e n children a r e p r a i s e d f o r intelligence, in o t h e r w o r d s , they resist a c c e p t i n g a c h a l l e n g e a n d d o i n g things f r o m w h i c h they c a n learn a lot. In a

clever experiment

psychologists

Claudia

illustrating this p o i n t , d e v e l o p m e n t a l

Mueller

and

Carol

Dweck

told

children

that they had d o n e very well on p r o b l e m s f r o m the R a v e n Prog r e s s i v e M a t r i c e s test a n d p r a i s e d t h e m e i t h e r f o r b e i n g b r i g h t o r for w o r k i n g hard. T h e y then o f f e r e d the children the o p p o r t u n i t y t o w o r k o n a n o t h e r s e t o f p r o b l e m s — e i t h e r e a s y o n e s ( " s o I'll d o w e l l " ) o r h a r d p r o b l e m s t h a t w o u l d c h a l l e n g e t h e m ( " s o I'll l e a r n a lot f r o m t h e m , e v e n if I w o n ' t l o o k so s m a r t " ) . S i x t y - s i x p e r c e n t of the children w h o w e r e praised f o r their intelligence c h o s e to w o r k on easy problems that w o u l d s h o w that they w e r e smart; over 90 percent of children praised for hard w o r k chose p r o b l e m s that they w o u l d learn a lot f r o m . If the children did well b e c a u s e they w e r e s m a r t , they did n o t w a n t t o risk f i n d i n g o u t that they w e r e not so s m a r t a f t e r all. If they did well b e c a u s e they w o r k e d h a r d , t h e y w a n t e d p r o b l e m s t h a t w o u l d test t h e i r l i m i t s a n d t e a c h them h o w to do even better. B e f o r e t h e c h i l d r e n a c t u a l l y g o t a c h a n c e t o w o r k 011 a p r o b l e m set o f t h e i r c h o i c e , M u e l l e r a n d D w e c k r e q u i r e d t h e m t o w o r k o n a second set of p r o b l e m s that w e r e m u c h m o r e d i f f i c u l t t h a n the first set. T h e c h i l d r e n w e r e then a s k e d t o e x p l a i n w h y they h a d performed

p o o r l y o n the s e c o n d set o f p r o b l e m s . T h e children

p r a i s e d f o r i n t e l l i g e n c e b a s e d o n p e r f o r m a n c e o n t h e f i r s t set o f p r o b l e m s w e r e m o r e l i k e l y t o t h i n k t h a t t h e i r f a i l u r e 011 t h e s e c o n d set o f p r o b l e m s reflected lack o f a b i l i t y ; c h i l d r e n p r a i s e d f o r hard w o r k initially w e r e m o r e likely to think that their f a i l u r e on t h e s e c o n d set o f p r o b l e m s w a s d u e t o l a c k o f e f f o r t . C h i l d r e n p r a i s e d f o r a b i l i t y w e r e less l i k e l y t o w a n t t o c o n t i n u e t o w o r k o n the p r o b l e m s a n d r e p o r t e d e n j o y i n g w o r k i n g o n the s e c o n d set o f t a s k s less t h a n d i d t h o s e p r a i s e d f o r h a r d w o r k . A s i c i n g 011 t h e c a k e , M u e l l e r a n d D w e c k then had the children w o r k on a third set o f p r o b l e m s . C h i l d r e n w h o h a d i n i t i a l l y b e e n p r a i s e d f o r i n t e l -

INTELLIGENCE AND HOW TO GET IT

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ligence s o l v e d f e w e r p r o b l e m s than those initially praised f o r hard w o r k . T h e m o r a l o f this e x p e r i m e n t a l p a r a b l e seems clear: praise for effort, not smarts.

Avoid "Contracts" to Give Rewards for Activities That Are Intrinsically Rewarding It is not a g r e a t idea to p r o m i s e y o u r child a r e w a r d for d o i n g something you w a n t to encourage, if y o u r child already has some interest and

in

David

it.

With developmental

Green,

I

watched

psychologists

nursery

school

Mark

Lepper

children

engage

in a n o v e l a c t i v i t y — d r a w i n g w i t h m a g i c m a r k e r s . M o s t of the children d r e w w i t h the m a r k e r s a n d clearly e n j o y e d the activity. We later p r o m i s e d s o m e children a r e w a r d if they w o u l d d r a w s o m e t h i n g with the m a g i c m a r k e r s for us, w h i c h they gladly did. T h e n a c o u p l e of w e e k s later the m a g i c m a r k e r s w e r e put out for children t o play w i t h a g a i n . C h i l d r e n w h o had been r e w a r d e d for playing with

the m a g i c m a r k e r s d r e w w i t h t h e m less t h a n

children w h o had not been r e w a r d e d — a n d their d r a w i n g s w e r e of l o w e r q u a l i t y . In e f f e c t , the " c o n t r a c t " had turned play into work.

We

praised

the

products

of other

children,

who

were

not p r o m i s e d a r e w a r d , a n d these children subsequently played w i t h the m a g i c m a r k e r s m o r e t h a n did c h i l d r e n w h o w e r e neither promised a r e w a r d nor praised. So if y o u w a n t children to d o s o m e t h i n g , p r a i s e t h e m f o r d o i n g it. D o n ' t p r o m i s e t h e m a r e w a r d f o r d o i n g it. Sometimes, however, contracting for rewards can be a good idea.

If the child

is not going to do something without being

o f f e r e d an extrinsic r e w a r d , then

r e w a r d s m a y h a v e t o b e the

o r d e r o f t h e d a y . I f a c h i l d h a s l o w initial i n t e r e s t i n a n a c t i v i t y , the r e w a r d m a y s e r v e to get the child to try it a n d p e r h a p s find t h a t t h e r e a r e g e n u i n e a t t r a c t i o n s t o it. I s u s p e c t t h a t t h e r e w a r d a s p e c t of the K I P P c h a r t e r s c h o o l s m a y be a g o o d idea f o r their c h i l d r e n , m a n y o f w h o m w i l l h a v e f o u n d little t o i n t e r e s t t h e m i n their p r e v i o u s schools.

Raising Your Child's Intelligence . . . and Your Oivn

Effective

191

Tutoring

W h e n y o u t u t o r y o u r c h i l d r e n , try t o k e e p i n m i n d M a r k L e p per's five Cs tutoring guide f r o m C h a p t e r 4: e n c o u r a g e a sense of control,

challenge

your

a n d contextualize b y

child,

instill

relating the task

confidence,

foster

curiosity,

to the real

world

or to a

m o v i e o r T V s h o w . I n a d d i t i o n , d o n ' t s w e a t the small errors like forgetting to w r i t e d o w n the m i n u s sign; try to p r e v e n t the child f r o m m a k i n g a m i s t a k e unless there is a g o o d lesson to be learned f r o m it; d o n ' t d u m b d o w n t h e m a t e r i a l f o r t h e s a k e o f t h e c h i l d ' s self-esteem but rather c h a n g e the w a y it is presented; ask leading q u e s t i o n s ; a n d don't g i v e m u c h p r a i s e s o a s t o a v o i d m a k i n g t h e child feel e v a l u a t e d .

The

Schools

F i n a l l y — s o m e suggestions a b o u t dealing with the schools. T o the e x t e n t y o u c a n , try t o g e t y o u r c h i l d i n t o c l a s s r o o m s w i t h t h e b e s t teachers, especially for the first g r a d e . A v o i d r o o k i e teachers. If y o u r s c h o o l d o e s not use p r o v e n c o m p u t e r p r o g r a m s f o r teachi n g r e a d i n g , m a t h , a n d s c i e n c e , try t o g e t i t t o c o n s i d e r d o i n g s o . G o t o the U.S.

Department of Education's

W e b site f o r W h a t

W o r k s C l e a r i n g h o u s e so that y o u can cite c h a p t e r a n d verse f o r w h y certain p r o g r a m s s h o u l d b e used a t y o u r c h i l d ' s g r a d e level. If y o u r child's s c h o o l d o e s n ' t use a n y of the c o o p e r a t i v e learning tools, w h e r e children w o r k o n s o l v i n g p r o b l e m s a n d c r e a t i n g k n o w l e d g e together, e n c o u r a g e the s c h o o l to do so, again citing the W h a t W o r k s C l e a r i n g h o u s e . F i n d o u t i f the p r i n c i p a l a t y o u r child's school is a w a r e of w h o the g o o d teachers are and ask if it i s p o s s i b l e t o r e w a r d t h e b e t t e r o n e s . I f it's n o t p o s s i b l e t o r e w a r d teacher quality,

press

your

school

board

to

make

it possible.

(Union c o n t r a c t s m a y f o r b i d r e w a r d i n g o n the basis o f a n y t h i n g but seniority. In that case, y o u can e n c o u r a g e y o u r s c h o o l b o a r d t o r e w a r d all t e a c h e r s a t h i g h - p e r f o r m i n g s c h o o l s . )

Discourage

y o u r s c h o o l b o a r d f r o m p u t t i n g a lot of e m p h a s i s on t e a c h e r s get-

INTELLIGENCE AND HOW TO GET IT

1192

ring certification a n d higher degrees, b e c a u s e there is no evidence that teachers with certificates or higher degrees are a n y better at their jobs. T e a c h e r time is better spent w o r k i n g on teaching skills, w i t h the help o f peers a n d e x p e r t s w h o o b s e r v e them a n d give them feedback. In

short,

you can

use m a n y of the

lessons

in

this

improve your children's intelligence—and your own.

book

to

EPILOGUE

What W e N o w K n o w about Intelligence a n d A c a d e m i c Achievement

THE STRONG HEREDITARIAN v i e w of i n t e l l i g e n c e h o l d s t h a t i n t e l l i g e n c e is mostly a matter of genes. Y o u are only going to be as smart as y o u r genes a l l o w , a n d nothing m u c h in the e n v i r o n m e n t — n e i t h e r the w a y y o u a r e b r o u g h t u p i n y o u r f a m i l y n o r t h e k i n d o f s c h o o l s you go t o — i s going to significantly change that. M a n y if not most scientists w h o study intelligence a n d m a n y if not m o s t l a y p e o p l e i n the U n i t e d S t a t e s b e l i e v e t h i s . S u c h t h i n k i n g i s e x t r e m e l y u n f o r tunate f o r the individual, because it implies that hard w o r k c a n p r o d u c e little i n t h e w a y o f i m p r o v e m e n t t o " r e a l " i n t e l l i g e n c e . I t is a disaster f o r public policy because it implies that e d u c a t i o n a l interventions are d o o m e d to failure. F o r t u n a t e l y , the v i e w is quite w r o n g . A n d here is h o w we k n o w . T h e r e i s n o f i x e d v a l u e f o r the h e r i t a b i l i t y o f i n t e l l i g e n c e . I t d i f f e r s f r o m o n e p o p u l a t i o n l i v i n g i n o n e set o f c i r c u m s t a n c e s , t o a n o t h e r p o p u l a t i o n i n a n o t h e r set o f c i r c u m s t a n c e s . I f the e n v i r o n m e n t is highly f a v o r a b l e to the g r o w t h of intelligence, then the h e r i t a b i l i t y o f i n t e l l i g e n c e i s i n d e e d f a i r l y h i g h — p e r h a p s a s h i g h a s 7 0 p e r c e n t . T h i s i s the s i t u a t i o n t h a t e x i s t s f o r t h e u p p e r middle class in developed countries. T h e e n v i r o n m e n t s they create p r o m o t e i n t e l l i g e n c e , a n d o n e f a m i l y d i f f e r s little f r o m a n o t h e r i n 193

EPILOGUE

194

that respect. At the limiting e x t r e m e of identical environments for e v e r y o n e in a given g r o u p , the only f a c t o r that can influence differences in intelligence is genetics. T h e upper middle class comes close e n o u g h to that situation that heredity for that g r o u p can be very i m p o r t a n t in determining d i f f e r e n c e s in intelligence. But

if the

between

environment

is

highly

individual families—then

variable—differing greatly

the e n v i r o n m e n t is g o i n g to

p l a y the m a j o r role in d i f f e r e n c e s in intelligence b e t w e e n indiv i d u a l s . A n d this i s the s i t u a t i o n f o r the p o o r . F o r t h e m , o n l y 1 0 p e r c e n t of the v a r i a t i o n in intelligence is driven by heredity, w h i c h means

that

improving

the

environment

of children

born

into

p o o r families could h a v e a big effect on intelligence. A n d in fact if y o u raise a p o o r child in an u p p e r - m i d d l e - c l a s s h o u s e h o l d , the e x p e c t e d v a l u e a d d e d is at least iz IQ points and m a y be as high as i 8 IQ points. T h e effect on a c a d e m i c achievement is also very g r e a t — a t least half a s t a n d a r d d e v i a t i o n a n d under s o m e circumstances as m u c h as a full s t a n d a r d deviation. Entirely aside f r o m the degree to w h i c h heritability is i m p o r t a n t for one g r o u p or another in

the p o p u l a t i o n , heritability places

n o limits w h a t s o e v e r o n m o d i f i a b i l i t y — f o r a n y b o d y . T h e height of people in d e v e l o p e d countries has increased greatly in recent g e n e r a t i o n s — a n d this increase h a s n o t h i n g t o d o with genetics. T h e r e has been a similarly striking increase in IQ o v e r the past c e n t u r y . T h e s c o r e s o n I Q tests h a v e i n c r e a s e d b y m o r e than

18

p o i n t s in the last s i x t y y e a r s a n d p r o b a b l y by the better part of t w o s t a n d a r d d e v i a t i o n s ( 3 0 points) o v e r the p a s t h u n d r e d years. A n d on

the

Raven

P r o g r e s s i v e M a t r i c e s — t h e test h e r a l d e d

for

decades as being a culture-free m e a s u r e of true intelligence—the g a i n h a s been t w o s t a n d a r d d e v i a t i o n s i n less t h a n s i x t y y e a r s . W h y h a v e the g a i n s o c c u r r e d ? It is s i m p l e at base: the s c h o o l s a n d the culture have c h a n g e d radically in such a w a y as to affect s c o r e s o n m a n y o f the subtests o f I Q tests. P a r e n t s a n d s c h o o l s increasingly teach children h o w to categorize objects and events in t a x o n o m i c t e r m s s u i t a b l e f o r scientific analysis. T h e m e d i a teach children the w a y s o f the w o r l d — w h y policemen w e a r u n i f o r m s ,

Epilogue

195

w h y street a d d r e s s e s a r e n u m b e r e d i n o r d e r , a n d w h y p e o p l e p a y taxes—resulting in

higher scores on comprehension subtests of

I Q tests. I m p r o v e m e n t s o n t h e R a v e n m a t r i c e s — a n d i n t h e f l u i d intelligence underlying p e r f o r m a n c e on i t — c a n be traced at least in part to the e v e r - m o r e g e o m e t r i c a n d analytic w a y s of teaching arithmetic over recent decades, and possibly in part to c o m p u t e r g a m e s . A f e w y e a r s a g o M c D o n a l d ' s w a s i n c l u d i n g i n its H a p p y M e a l s m a z e s that w e r e m o r e d i f f i c u l t t h a n the m a z e s i n a n I Q test for gifted children! A n d then there is the f a c t that p e o p l e a r e receiving a lot m o r e e d u c a t i o n than e v e r b e f o r e . In a c e n t u r y the m e a n n u m b e r of y e a r s of schooling has gone f r o m seven to fourteen. Since a

year of

school adds as much to IQ scores as t w o years of age, it w o u l d be astonishing if IQ had not changed radically over that period. H o w m u c h o f the I Q g a i n s can

be called

"real"

intelligence

gains? I can say several things a b o u t that. First of all, it is o u t of the question that the g r e a t - g r a n d c h i l d r e n of people w h o w e r e ten y e a r s o l d i n

1 9 1 0 are t w o standard deviations smarter, if we

define intelligence b r o a d l y as the " a b i l i t y to reason, p l a n , solve problems, think abstractly, c o m p r e h e n d c o m p l e x ideas . . . and learn f r o m e x p e r i e n c e . " O n the other h a n d , p e o p l e t o d a y really are m o r e intellectually c a p a b l e than their f o r e b e a r s . C h i l d r e n w h o c a n tell y o u w h y s t r e e t a d d r e s s e s a r e n u m b e r e d c o n s e c u t i v e l y a r e smarter in s o m e sense than children w h o can't. Being able to think a b o u t the similarities o f o b j e c t s a n d e v e n t s i n t a x o n o m i c t e r m s is a real a d v a n t a g e . Heuristics f o r r e a s o n i n g , such as p r o c e d u r e s f o r h y p o t h e s i s testing, a r e p a r t of the c u r r i c u l u m at e v e r y level of school, and they c a n be applied to e v e r y d a y p r o b l e m s . Planning and c h o o s i n g are t w o aspects of intelligence that h a v e been increased by virtue of w i despr ea d k n o w l e d g e of probability theory and cost-benefit reasoning. S i n c e s c h o o l m a k e s c h i l d r e n s m a r t e r , t h e r e i s n o d o u b t t h a t better s c h o o l s c a n m a k e t h e m s m a r t e r still. A l t h o u g h v o u c h e r s , c h a r ter s c h o o l s , w h o l e - s c h o o l i n t e r v e n t i o n s , a n d t e a c h e r c e r t i f i c a t i o n or higher academic degrees do not reliably i m p r o v e education,

EPILOGUE

196

other factors d o — a n d some matter a great deal. Teachers differ a lot in q u a l i t y , a n d so f i n d i n g w a y s to i m p r o v e the quality of teaching c o u l d m a k e a g r e a t d i f f e r e n c e . If we c o u l d replace the b o t t o m 5 p e r c e n t of t e a c h e r s e v e r y y e a r w i t h a v e r a g e - q u a l i t y t e a c h e r s , the level o f c h i l d r e n ' s a c a d e m i c p e r f o r m a n c e w o u l d

increase hugely

in just a f e w years. Use of computer-assisted f o r m s of teaching c a n p r o d u c e h u g e g a i n s in the rate of learning, a n d s o m e types of c o o p e r a t i v e l e a r n i n g are highly e f f e c t i v e . A n d recall the H e r r n stein d e m o n s t r a t i o n w i t h an intensive p r o g r a m in V e n e z u e l a that radically i m p r o v e d the p r o b l e m - s o l v i n g skills of o r d i n a r y junior high s c h o o l students. It a l s o raised their IQ s c o r e s by a nontrivial a m o u n t — 5 p o i n t s o n a t y p i c a l test o f m u l t i p l e p r o b l e m - s o l v i n g skills. The

received

opinion

about

the

relationship

between

social

class a n d intelligence is that intelligence, w h i c h is largely inherited, drives social class. S m a r t e r p e o p l e h a v e better genes so they are d e s t i n e d t o rise i n s o c i e t y , w h e r e a s less s m a r t p e o p l e h a v e w o r s e genes so they are destined to fall. It is true that intelligence is partially heritable, a n d m o r e intelligent p e o p l e on a v e r a g e will be of a higher social class in virtue of their greater inherited intelligence. B u t I believe t h a t the role of g e n e t i c i n h e r i t a n c e in d e t e r m i n i n g social class is fairly s m a l l . T h e d i f f e r e n c e b e t w e e n the a v e r a g e IQ of the children of the l o w e r third of the s o c i o e c o n o m i c status (SES) d i s t r i b u t i o n a n d the a v e r a g e IQ of the children of the u p p e r third i s a b o u t 1 0 p o i n t s . W e k n o w that s o m e o f this i s d u e t o biological but not genetic factors, including exercise, breast-feeding, and e x p o s u r e to alcohol or cigarette s m o k e , as well as hazardous c h e m i c a l s a n d p o l l u t i o n . A n d s o m e of it is d u e to the d i s r u p t i o n in s c h o o l s of l o w e r - S E S children a n d to the fact that peers are pulling intelligence mostly in a d o w n direction. We also k n o w that socialization in l o w e r - S E S h o m e s is not optimal for d e v e l o p i n g either IQ or s c h o o l readiness. M o r e o v e r , a child born into r o u g h l y the bott o m sixth of the S E S distribution will h a v e an IQ 12 to 18 points higher if raised by parents f r o m roughly the t o p quarter of the S E S distribution. All of this d o e s not leave m u c h r o o m for genes in the

Epilogue

197

social-class e q u a t i o n . 1 do not d o u b t that g e n e s play a role, but I w o u l d be surprised to f i n d that the d i f f e r e n c e s in inherent genetic potential of the social classes are very great. C e r t a i n l y m u c h if n o t m o s t of the i o points s e p a r a t i n g the a v e r a g e of the children of the l o w e r third a n d the a v e r a g e of the children of the u p p e r third is e n v i r o n m e n t a l in origin. F o r the race d i f f e r e n c e i n I Q , w e c a n b e c o n f i d e n t that g e n e s p l a y n o r o l e a t all. M o s t o f t h e e v i d e n c e o f f e r e d f o r a g e n e t i c c o m ponent to the race d i f f e r e n c e is indirect and readily refuted. V i r t u a l l y all o f t h e d i r e c t e v i d e n c e , w h i c h i s d u e m o s t l y t o t h e n a t u r a l e x p e r i m e n t resulting f r o m the f a c t that A m e r i c a n " b l a c k s " r a n g e f r o m being completely African to largely E u r o p e a n in

heritage,

i n d i c a t e s n o g e n e t i c d i f f e r e n c e a t all w i t h r e s p e c t t o I Q . A n d t h e d i f f e r e n c e b e t w e e n the races in both IQ a n d a c a d e m i c a c h i e v e m e n t is being reduced at the rate of a b o u t o n e - t h i r d of a s t a n d a r d d e v i a tion per g e n e r a t i o n . T h e IQ of the a v e r a g e black is n o w g r e a t e r than that of the a v e r a g e w h i t e in i 9 5 0 . T h e No Child L e f t Behind Act d e m a n d s that the difference in a c a d e m i c a c h i e v e m e n t b e t w e e n the classes a n d b e t w e e n the races be erased in half a g e n e r a t i o n by the s c h o o l s a l o n e . T h i s is a b s u r d . It ignores the f a c t that class a n d race d i f f e r e n c e s begin in e a r l y infancy and have as much to do with e c o n o m i c factors and neighborhood and cultural differences as with schools. T h a t i s the b a d n e w s a b o u t g a p r e d u c t i o n . T h e g o o d n e w s i s that big i m p r o v e m e n t s in IQ a n d a c a d e m i c a c h i e v e m e n t f o r l o w e r S E S and m i n o r i t y children a r e p o s s i b l e . A n d w e k n o w a t least the outlines of w h a t

those

improvements

look

like.

Half-measures

h a v e been tried a n d a r e n o t g o i n g to m a k e a lot of d i f f e r e n c e . We need intensive early c h i l d h o o d e d u c a t i o n

for the p o o r , a n d

w e n e e d h o m e v i s i t a t i o n t o t e a c h p a r e n t s h o w t o e n c o u r a g e intellectual d e v e l o p m e n t . S u c h e f f o r t s c a n

produce huge immediate

gains in IQ and e n o r m o u s long-term gains in a c a d e m i c achievement and occupational attainment. Highly ambitious elementary, junior high, and high school p r o g r a m s can also p r o d u c e massive gains in a c a d e m i c achievement. A n d a variety of simple, cost-free

EPILOGUE

198

interventions, including, most notably, simply convincing students that their intelligence is u n d e r their c o n t r o l to a substantial extent, can m a k e a big d i f f e r e n c e to a c a d e m i c achievement. Believing

that

intelligence

is

under

your

control—and

hav-

ing p a r e n t s w h o d e m a n d a c h i e v e m e n t — c a n d o w o n d e r s . A t any rate that has been true for A s i a n s and J e w s . T h e r e is no reliable evidence of a genetic d i f f e r e n c e in intelligence between people of East A s i a n descent a n d people of E u r o p e a n descent. In fact, there i s little d i f f e r e n c e i n i n t e l l i g e n c e b e t w e e n t h e t w o g r o u p s a s m e a sured by IQ tests. S o m e e v i d e n c e indicates that E a s t A s i a n s start school with lower I Q s than do white Americans. After a few years of s c h o o l this d i f f e r e n c e s e e m s to d i s a p p e a r .

But the a c a d e m i c

a c h i e v e m e n t of E a s t A s i a n s — e s p e c i a l l y in m a t h a n d the sciences, w h e r e e f f o r t counts f o r a lot—is light-years beyond that of European Americans. Americans of East Asian extraction also differ little i n I Q f r o m E u r o p e a n A m e r i c a n s . I n a n y c a s e , t h e a c a d e m i c achievement

and

occupational

attainment

of

Asian

Americans

exceed by a great a m o u n t w h a t they " s h o u l d " be accomplishing g i v e n t h e i r I Q s . T h e e x p l a n a t i o n f o r t h e A s i a n / W e s t e r n g a p lies i n hard w o r k and persistence. J e w i s h culture undoubtedly has similarly beneficial effects. J e w ish v a l u e s e m p h a s i z e a c c o m p l i s h m e n t i n g e n e r a l a n d

intellectual

attainment in particular. Differences between J e w s and non-Jews in i n t e l l e c t u a l a c c o m p l i s h m e n t a t the h i g h e s t l e v e l s a r e v e r y g r e a t . A g e n e t i c e x p l a n a t i o n f o r this i s n o t r e q u i r e d i n a s m u c h a s e v e n g r e a t e r differences have occurred for A r a b s and Chinese versus Europeans in the M i d d l e A g e s , for d i f f e r e n c e s between E u r o p e a n countries a t v a r i o u s p o i n t s since the M i d d l e A g e s (with reversals o c c u r r i n g b e t w e e n Italy a n d E n g l a n d a n d w i t h m o v e m e n t f r o m s a v a g e r y t o sagacity in scarcely t w o centuries in Scotland), and for regional differences in the United States. We are left with an IQ d i f f e r e n c e of two-thirds to a standard deviation between J e w s and non-Jews. At least s o m e of this d i f f e r e n c e is surely cultural in origin. F i n a l l y , there is m u c h that we c a n do to increase the intelligence and academic achievement of ourselves and our children. Every-

Epilogue

199

thing f r o m the biological (exercise a n d a v o i d a n c e of s m o k i n g a n d drinking for pregnant w o m e n , and breast-feeding for newborns) t o the didactic (teaching c a t e g o r i z a t i o n , f o l l o w i n g g o o d t u t o r i n g principles) can m a k e a difference to intelligence. W e c a n n o w s h a k e o f f t h e y o k e o f h e r e d i t a r i a n i s m i n all o f o u r thinking a b o u t intelligence. Believing that o u r intelligence is substantially under o u r c o n t r o l w o n ' t m a k e u s s m a r t b y itself. B u t it's a g o o d s t a r t .

APPENDIX A

Informal Definitions of Statistical T e r m s

ALL KINDS OF PHENOMENA a r e f o u n d to be d i s t r i b u t e d n o r m a l l y , t h a t is, in the s h a p e of a bell curve, s h o w n in F i g u r e A . i . F o r e x a m p l e , if w e w e r e t o plot o n a g r a p h the n u m b e r o f e g g s p r o d u c e d w e e k l y b y d i f f e r e n t hens, the n u m b e r of e r r o r s o c c u r r i n g d u r i n g p r o d u c t i o n of a given type o f a u t o m o b i l e , o r the I Q test s c o r e s f o r a g r o u p o f p e o p l e , the s h a p e o f the c u r v e r e p r e s e n t i n g the d a t a w o u l d a p p r o x i m a t e that o f the bell c u r v e . W e d o n o t need t o g o into the m a t h e m a t i cal r e a s o n s f o r w h y d i s t r i b u t i o n s tend t o h a v e this s h a p e . W h a t i s i m p o r t a n t is that the n o r m a l d i s t r i b u t i o n c u r v e h a s u s e f u l p r o p e r t i e s f o r m a k i n g i n f e r e n c e s a b o u t w h e r e o b s e r v a t i o n s s t a n d i n relation t o o t h e r o b s e r v a t i o n s . T h e n o r m a l c u r v e i n F i g u r e A . i i s d i v i d e d into standard deviations—so

named

b e c a u s e the a v e r a g e s c o r e d e v i a t e s

f r o m the m e a n by ( a p p r o x i m a t e l y ) this a m o u n t . In a p e r f e c t l y n o r m a l d i s t r i b u t i o n , w h i c h is a m a t h e m a t i c a l a b s t r a c t i o n b u t o n e that is a p p r o x i m a t e d s u r p r i s i n g l y o f t e n if there a r e a v e r y large n u m b e r of o b s e r v a t i o n s , a b o u t 6 8 p e r c e n t o f all o b s e r v a t i o n s f a l l b e t w e e n + i a n d —i s t a n d a r d d e v i a t i o n ( a b b r e v i a t e d S D ) f r o m the m e a n (set at o in the c u r v e in F i g u r e A . i ) . A n o t h e r set of u s e f u l f a c t s a b o t i t the c o n c e p t o f s t a n d a r d d e v i a t i o n c o n c e r n s the r e l a t i o n b e t w e e n p e r c e n tiles a n d s t a n d a r d d e v i a t i o n s . A b o u t 8 4 p e r c e n t o f all o b s e r v a t i o n s 201

APPENDIX A

202

occur at or below i SD above the mean; an observation at exactly i SD above the mean is at the 84th percentile of the distribution. Sixteen percent, the remaining observations, occur above that standard deviation. Almost 98 percent of all observations lie below z SDs above the mean. A score at exactly z+ SDs from the mean is at the 98th percentile. The remaining z percent of observations are above that. Nearly all observations fall between 3 SDs below the mean and 3 SDs above it. By convention, the SD of the distribution of scores on most IQ tests is forced to be 1 5 (with a mean of 100).

Figure from

A.l.

The

the mean

scores and

distribution

Wechsler IQ scores given

ues fall between deviation

normal

above

curve,

with

marked by vertical lines and with below.

standard

deviations

corresponding percentile

Note that

68 percent of val-

1 standard deviation (cj) below the mean and 1 standard the

mean.

Standard deviations are useful units with which to describe effect sizesy for example, in determining how much difference a new teaching technique makes to what the students learn. The most common indicator of effect size is a statistic called Cohen's d, which is calculated as follows: the mean of group A minus the mean of group B divided by the average of the standard deviations of the two groups (or sometimes divided by the standard deviation just of group A). By convention, d values of .20 or less are deemed small. This is the equivalent of moving the experimental group's scores from the 50th percentile to almost the 60th percentile. You might not

Appendix

A

203

think that w a s such a small e f f e c t if the scores in question w e r e those that could be expected by y o u r child if he or she is taught by the n e w t e c h n i q u e (6oth percentile) v e r s u s the old t e c h n i q u e (50th percentile). A n d w h e t h e r y o u w o u l d be willing to pay f o r the t e c h n i q u e d e p e n d s in p a r t on h o w i m p o r t a n t the d i f f e r e n c e between

the

50th percentile and

60th

percentile

is.

If y o u are

measuring teaching effectiveness in terms of h o w quickly a child learns the touch typing system to a p r o f i c i e n c y of 40 w o r d s per minute, and the d i f f e r e n c e between the 50th a n d 60th percentiles amounts to a few days, you probably would not be willing to pay too much for that gain and w o u l d not w a n t your school system to pay m u c h f o r it either. If y o u are c o m p a r i n g the effectiveness of t w o high s c h o o l m a t h t e a c h i n g t e c h n i q u e s b y l o o k i n g a t a v e r a g e scores on the S A T e x a m , a n d o n e technique results in an a v e r a g e s c o r e of 5 0 0 a n d the o t h e r results in an a v e r a g e s c o r e of 52.0, this is the d i f f e r e n c e b e t w e e n the 5 0 t h a n d the 60th percentiles ( a s s u m ing that the S D o f S A T s c o r e s i s 1 0 0 ) . Y o u m i g h t b e w i l l i n g t o p a y s o m e s i g n i f i c a n t a m o u n t o f m o n e y f o r it. A n d y o u m i g h t b e h a p p y if y o u r school board paid a modest a m o u n t per pupil to spring for the m o r e e f f e c t i v e m e t h o d . By convention, d values of . 5 0 or so are considered

moder-

ate. In the w o r l d of IQ tests a n d a c a d e m i c a c h i e v e m e n t , t h o u g h , an e f f e c t size of that m a g n i t u d e w o u l d n o r m a l l y be c o n s i d e r e d a b o m b s h e l l . It is the d i f f e r e n c e b e t w e e n an S A T s c o r e on the m a t h section of 5 0 0 a n d o n e of 5 5 0 — s o m e t i m e s e n o u g h to m a k e the difference between being accepted to a fairly g o o d university a n d a significantly better university. Y o u a n d y o u r s c h o o l system might be willing to pay a considerable a m o u n t to a d o p t a n e w method that w o u l d m o v e the a v e r a g e child f r o m the 5 0 t h percentile o f S A T m a t h scores t o a b o u t the 7 0 t h percentile ( w h i c h i s w h a t . 5 0 S D c o r r e s p o n d s to). E f f e c t sizes i n the r a n g e o f . 7 0 t o 1 . 0 0 S D are c o n s i d e r e d large. F o r e d u c a t i o n or intelligence d i f f e r e n c e s , an e f f e c t size of 1 . 0 0 is huge. T h e putative IQ difference between blacks and whites is on the o r d e r of 1 . 0 0 S D . In C h a p t e r 6, I d i s c u s s e d w h e t h e r t h a t is

APPENDIX A

204

the actual m a g n i t u d e of the d i f f e r e n c e . If it w e r e , it w o u l d m e a n that the a v e r a g e IQ for blacks stood at the 1 6 t h percentile of the distribution of I Q s for whites. An intervention that took children f r o m , on a v e r a g e , the 50th percentile of the national distribution in math a c h i e v e m e n t scores to the 84th percentile w o u l d be considered w o r t h it even at very g r e a t cost. F o r a n a t i o n , the increase in competitiveness that c o u l d result f r o m such an i m p r o v e m e n t in math scores would be worth an enormous economic outlay. T h e correlation

coefficient

is a

m e a s u r e of t h e d e g r e e of l i n e a r

a s s o c i a t i o n b e t w e e n t w o v a r i a b l e s . F o r e x a m p l e , the c o r r e l a t i o n between IQ scores and a c a d e m i c g r a d e s h a p p e n s to fall a r o u n d . 5 0 , indicating a m o d e r a t e l y high degree of a s s o c i a t i o n . At least a

moderate

association

should

be

expected

because

IQ

tests

were invented to predict h o w well people would do in school. C o r r e l a t i o n c o e f f i c i e n t s r a n g e b e t w e e n —1, i n d i c a t i n g a p e r f e c t negative association, and + 1 , indicating a perfect positive association. A c o r r e l a t i o n c o e f f i c i e n t of o indicates no association at all. T h e c o r r e l a t i o n c o e f f i c i e n t i s a n o t h e r m e a s u r e o f e f f e c t size or, rather, of relationship m a g n i t u d e , with values l o w e r than . 3 0 considered to be small, values of .30 to .50 considered moderate, and values a b o v e . 5 0 considered to be large. But, as with effect size, w h e t h e r a correlation is i m p o r t a n t or not has m o r e to do w i t h the v a r i a b l e s represented in the c o r r e l a t i o n than with the size of the c o r r e l a t i o n . T h e c o r r e l a t i o n c o e f f i c i e n t is interpretable i n s t a n d a r d d e v i a t i o n t e r m s . A c o r r e l a t i o n o f .2.5

between t w o

v a r i a b l e s indicates that an increase of x SD in the first v a r i a b l e i s a s s o c i a t e d w i t h a n i n c r e a s e o f .2.5 S D i n t h e s e c o n d v a r i a b l e ; a correlation of . 5 0 is associated with an increase of . 5 0 S D . So if the c o r r e l a t i o n b e t w e e n c l a s s size a n d s t u d e n t a c h i e v e m e n t on a s t a n d a r d i z e d t e s t w e r e — .2.5, t h e n a d e c r e a s e of c l a s s s i z e by 1 S D c o u l d b e e x p e c t e d t o p r o d u c e a n i m p r o v e m e n t i n test s c o r e s o f .2.5 S D ( a s s u m i n g t h a t t h e r e l a t i o n s h i p b e t w e e n c l a s s s i z e a n d test s c o r e s i s g e n u i n e l y a c a u s a l o n e ) . Multiple

regression

is

a

way

of

simultaneously

correlating

a

n u m b e r of independent or predictor variables with s o m e target

Appendix

A

205

or outcome variable.

For example, we might want to compare

the d e g r e e to w h i c h a n u m b e r of v a r i a b l e s p r e d i c t the a p p e a l of h o u s e s on the real estate m a r k e t . We m i g h t m e a s u r e the a r e a in s q u a r e feet, the n u m b e r of b e d r o o m s , the o p u l e n c e of the m a s t e r b a t h r o o m (for e x a m p l e , using an index based on the n u m b e r of sinks, the presence or a b s e n c e of a hot tub, a n d the use of high- or l o w - q u a l i t y materials), the a v e r a g e i n c o m e in the n e i g h b o r h o o d , a n d the c h a r m of the h o u s e as rated by a panel of potential b u y e r s . W e then c o r r e l a t e e a c h o f these v a r i a b l e s s i m u l t a n e o u s l y w i t h the a p p e a l of the h o u s e as m e a s u r e d by the a m o u n t that it c a n fetch o n the m a r k e t — t h e t a r g e t v a r i a b l e .

We get an estimate of the

contribution of a given v a r i a b l e to the m a r k e t v a l u e by f i n d i n g o u t t h e s i z e o f t h e c o r r e l a t i o n o f t h e v a r i a b l e w i t h m a r k e t v a l u e net o f t h e c o n t r i b u t i o n o f all t h e o t h e r v a r i a b l e s ( t h a t is, h o l d i n g all o t h e r v a r i a b l e s c o n s t a n t ) . T h u s , c h a r m , h o l d i n g all o t h e r v a r i a b l e s c o n s t a n t , m i g h t b e c o r r e l a t e d .2.5 w i t h m a r k e t v a l u e , a n d m a s t e r b a t h o p u l e n c e m i g h t b e c o r r e l a t e d . 1 0 w i t h m a r k e t v a l u e . B u t all o f the v a r i a b l e s a r e g o i n g t o b e c o r r e l a t e d w i t h o n e a n o t h e r , a n d s o m e o f the v a r i a b l e s a r e m e a s u r e d w i t h g r e a t e r p r e c i s i o n than others, and s o m e of the variables h a v e a c a u s a l relation with others w h i l e others do not, a n d s o m e v a r i a b l e s that h a v e not been measured are going to exert an effect on s o m e of those that have been m e a s u r e d . T h e result is that multiple-regression a n a l y s i s c a n m i s l e a d us. T h e a c t u a l m a g n i t u d e o f the c o n t r i b u t i o n o f c h a r m t o m a r k e t price could be substantially higher or l o w e r than the figure o f .2.5 d e r i v e d f r o m t h e r e g r e s s i o n a n a l y s i s . There are endless numbers of instances where multiple-regression analysis gives one impression a b o u t causality and actual experiments, w h i c h are nearly a l w a y s greatly p r e f e r a b l e f r o m the s t a n d point of causal inference, give another. For e x a m p l e , a b o u t fifteen years a g o , I attended a c o n s e n s u s d e v e l o p m e n t c o n f e r e n c e put on b y the N a t i o n a l Institutes o f H e a l t h . T h e p u r p o s e o f the c o n f e r e n c e w a s t o r e v i e w r e s e a r c h 011 m e d i c a l p r o c e d u r e s v e r s u s s u r g i c a l procedures as treatments for c o r o n a r y artery blockage and reach consensus about

the a p p r o p r i a t e n e s s of each.

The

results of a

APPENDIX A

206

very

large number of expensive American

studies, paid

for by

government funds, were available. In those studies, researchers put a

host of variables a b o u t patients such

age, and socioeconomic status (SES)

as

illness history,

into a multiple-regression

e q u a t i o n a n d d r e w c o n c l u s i o n s a b o u t the effect of treatment type " n e t " o f all t h e o t h e r w a y s i n w h i c h p a t i e n t s v a r i e d . B u t b e c a u s e Internal R e v i e w B o a r d s g o v e r n i n g research policy in the United S t a t e s r e q u i r e a l l o w i n g p a t i e n t s t o c h o o s e t h e i r t r e a t m e n t (it i s f a r f r o m c l e a r t h a t t h i s i s a c t u a l l y i n t h e p a t i e n t s ' i n t e r e s t s ) , all the

U.S.

evidence

was

undermined

by

t h e self-selection

artifact

(see b e l o w ) . B u t i n a d d i t i o n t o the A m e r i c a n s t u d i e s w e r e t w o E u r o p e a n studies based on

the r a n d o m assignment of patients

to treatment. Q u i t e c o r r e c t l y , the panelists ignored the e x p e n s i v e A m e r i c a n studies a n d c o n s i d e r e d o n l y the results o f the E u r o p e a n studies. Let's consider namely,

an

e x a m p l e closer to

w h e t h e r size of class

the t o p i c o f this

book,

matters to student performance.

M u l t i p l e - r e g r e s s i o n a n a l y s i s tells u s t h a t , n e t o f s i z e o f s c h o o l , a n d a v e r a g e i n c o m e of families in the n e i g h b o r h o o d w h e r e the school is located, and teacher salary, and percentage of teachers w h o are certified, a n d a m o u n t of m o n e y s p e n t per pupil in the district, and so o n , a v e r a g e class size is u n c o r r e l a t e d w i t h s t u d e n t p e r f o r m a n c e (Hanushek,

1986;

Hoxby,

2 0 0 0 ; J e n c k s et al.,

1972.).

But one

w e l l - c o n d u c t e d , r a n d o m i z e d e x p e r i m e n t v a r y i n g class size o v e r a substantial a m o u n t ( 1 3 to 17 pupils per class as c o m p a r e d to 22 t o 2.5 p u p i l s p e r c l a s s ) f o u n d t h a t c l a s s s i z e v a r i e d t o t h a t d e g r e e produces an

i m p r o v e m e n t in

standardized

test p e r f o r m a n c e o f

m o r e t h a n .2.5 S D — a n d t h e e f f e c t o n b l a c k c h i l d r e n w a s g r e a t e r than the e f f e c t o n w h i t e children ( K r u e g e r ,

1 9 9 9 ) . This w a s not

m e r e l y a n o t h e r s t u d y o n t h e e f f e c t s o f c l a s s s i z e . I t replaced all t h e multiple-regression studies on class size. I o c c a s i o n a l l y cite multiple-regression studies in this b o o k , but s p a r i n g l y a n d a l w a y s w i t h a w a r n i n g to b e w a r e the results. Self-selection i s o n e o f t h e p r o b l e m s u n d e r l y i n g t h e d i f f i c u l t y o f interpreting correlational studies and multiple-regression analyses,

Appendix

A

207

and it is crucial to understand, for m a n y reasons. W h e n we say that IQ is correlated with o c c u p a t i o n a l success to a p a r t i c u l a r d e g r e e — s a y , . 4 0 — t h e r e is a

reflexive tendency to a s s u m e that

the relationship is entirely c a u s a l : higher IQ m a k e s a p e r s o n perf o r m a job better. But IQ is correlated with other f a c t o r s too. F o r e x a m p l e , higher IQ in a child is associated with higher S E S of that child's parents, w h i c h , f o r e x a m p l e , m a k e s it m o r e likely that the child will go to c o l l e g e regardless of the c h i l d ' s IQ level. A n d a college education, again

regardless of IQ level, m a k e s higher

o c c u p a t i o n a l status m o r e likely. T h u s , the correlation between IQ and occupational success is c o n t a m i n a t e d by the contribution of other variables like p a r e n t s ' S E S a n d college a t t e n d a n c e , w h i c h the c h i l d , o r s u b j e c t , h a s b e e n a l l o w e d t o " s e l f - s e l e c t . " (It i s o d d t o s a y that a person " s e l f - s e l e c t s " f o r s o m e t h i n g like p a r e n t s ' S E S , w h i c h the p e r s o n o b v i o u s l y did n o t c h o o s e . B u t the c o m p a r i s o n i s w i t h the i n v e s t i g a t o r , w h o clearly did n o t d e t e r m i n e the level f o r that v a r i a b l e , so it is as if the p e r s o n d e t e r m i n e d the level. At a n y rate, something a b o u t the person that the investigator h a d no control o v e r w a s a l l o w e d to vary w i t h o u t the investigator's selection, or e v e n k n o w l e d g e , o f t h e p e r s o n ' s level 011 t h e v a r i a b l e . ) A n y time a study merely measures, as o p p o s e d to manipulates, a given variable, we have to recognize that the subject and not the i n v e s t i g a t o r h a s selected the level of the v a r i a b l e in q u e s t i o n — along with

the

levels on

all

other variables

measured

or

not.

T h i s gives up a huge degree of inferential p o w e r . In the class-size e x a m p l e , the i n v e s t i g a t o r u s i n g m u l t i p l e r e g r e s s i o n

has allowed

t h e level o n t h e c l a s s - s i z e v a r i a b l e t o b e s e l f - s e l e c t e d ( t h a t is, t h e investigator did not d e t e r m i n e class size), a n d the class-size varia b l e m a y b e a s s o c i a t e d w i t h all s o r t s o f o t h e r v a r i a b l e s t h a t m a y a m p l i f y o r block the e f f e c t s o f class size o n a c h i e v e m e n t . T h e o n l y w a y t o c o m p l e t e l y a v o i d the self-selection p r o b l e m i s f o r the investigator to select the v a l u e on the i n d e p e n d e n t or p r e d i c t o r variable (for e x a m p l e , big class versus small class) a n d then o b s e r v e its e f f e c t s o n t h e t a r g e t v a r i a b l e ( f o r e x a m p l e , a c h i e v e m e n t t e s t p e r f o r m a n c e ) . A l a s , this is not a l w a y s possible, so we h a v e to be

APPENDIX A

208

content with correlational analyses and multiple-regression analyses, hedged with c a v e a t s a b o u t the self-selection p r o b l e m . Finally, result—for

statistical example,

significance an

effect

tells

us

of class

the

likelihood

size o n

that

a

performance—

could h a v e o c c u r r e d by c h a n c e if the true effect is actually zero. T h e c o n v e n t i o n a l v a l u e f o r statistical significance is . 0 5 , meaning that a d i f f e r e n c e b e t w e e n t w o m e a n s , or a c o r r e l a t i o n of a g i v e n s i z e , w o u l d o c c u r b y c h a n c e o n l y 5 i n 1 0 0 t i m e s , o r 1 i n 2.0 times, in a s t u d y h a v i n g the s a m e design as the s t u d y in question. Statistical s i g n i f i c a n c e is v e r y m u c h a f u n c t i o n of the n u m b e r of o b s e r v a t i o n s . E v e n d i f f e r e n c e s s o s m a l l a s t o b e o f 110 p r a c t i c a l o r theoretical significance can be statistically significant if there are e n o u g h o b s e r v a t i o n s . E v e r y result based on a study that 1 report in this b o o k is statistically significant at least at the . 0 5 level, e x c e p t in o n e i n s t a n c e w h e r e I r e p o r t a result that is " m a r g i n a l l y signific a n t , " w i t h a p r o b a b i l i t y o f less t h a n . 1 0 t h a t t h e r e s u l t w o u l d h a v e been obtained by chance.

APPENDIX B

T h e C a s e f o r a Purely E n v i r o n m e n t a l Basis f o r Black/White D i f f e r e n c e s in IQ

IN THIS APPENDIX I r e v i e w a n d d i s p u t e t h e e v i d e n c e t h a t t h e IQ g a p between blacks and whites is substantially genetic in origin. T h e c a s e f o r g e n e t i c s i s p r e s e n t e d i n t h e c h a p t e r o n r a c e a n d intelligence

in

The

Bell

Curve

by

Richard

Herrnstein

and

Charles

M u r r a y ( 1 9 9 4 ) a n d in the recent r e v i e w article by Phillipe R u s h ton and A r t h u r J e n s e n ( 2 0 0 5 ) . But m a n y other scientists w o u l d also e n d o r s e at least s o m e of the c o n t e n t i o n s b e l o w a b o u t genetic determination. 1 . T h e heritability o f I Q w i t h i n the w h i t e p o p u l a t i o n

i s high.

H e n c e , it is p r o b a b l e that a v e r y l a r g e f r a c t i o n of the b l a c k / w h i t e g a p is a l s o genetic in o r i g i n . 2. T h e g a p is n o t d u e to p o s s i b l e c u l t u r a l d i f f e r e n c e s b e c a u s e it is g r e a t e r f o r a l l e g e d l y c u l t u r e - f a i r tests, such a s t h o s e i n v o l v i n g a n a l y s i s of the r e l a t i o n s h i p b e t w e e n g e o m e t r i c s h a p e s , than it is f o r c u l t u r e - l o a d e d items, such as f i n d i n g the a n a l o g y b e t w e e n

cotillion and square dance. 3. Blacks

from

sub-Saharan

Africa

have

according to Herrnstein and M u r r a y ,

even

lower

IQs

(75

1 9 9 4 ; 70 according to

R u s h t o n a n d J e n s e n , 2 0 0 5 ) than A f r i c a n A m e r i c a n s . T h e r e a s o n 209

APPENDIX A

210

f o r the superiority of A f r i c a n A m e r i c a n s (with a putative IQ of 8 5 ) i s t h a t t h e g e n e p o o l o f A f r i c a n A m e r i c a n s i s a b o u t 2 0 percent E u r o p e a n . 4 . B l a c k s d o r e l a t i v e l y w o r s e o n items w i t h high l o a d i n g s o n the s o - c a l l e d g f a c t o r ( f o r g e n e r a l i n t e l l i g e n c e ) , a n d high ^ - l o a d i n g items are m o r e influenced by genetics than are low ^-loading items. 5 . I n b r e e d i n g d e p r e s s i o n (the d e t r i m e n t a l results f o r I Q f o r the o f f s p r i n g o f c l o s e r e l a t i v e s ) a f f e c t s p e r f o r m a n c e o n s o m e items o n I Q tests m o r e t h a n o t h e r s . T h e s e items s h o w the g r e a t e s t d i f f e r e n c e between black and white scores, thus indicating that the m o s t g e n e t i c a l l y i n f l u e n c e d p a r t s o f the test s h o w the b i g g e s t black/white differences. 6 . C r a n i a l c a p a c i t y — b r a i n s i z e — i s c o r r e l a t e d w i t h I Q w i t h i n the w h i t e p o p u l a t i o n a n d w i t h i n the b l a c k p o p u l a t i o n , a n d w h i t e s have greater cranial capacity than blacks. 7. R e a c t i o n t i m e — i n a s e t u p in w h i c h p e o p l e place their finger on a button a n d then m o v e to touch a lighted bulb as q u i c k l y as

possible—is

lower

for

people

with

higher

IQs

and

for

w h i t e s t h a n f o r b l a c k s . ( L o w r e a c t i o n t i m e m e a n s high s p e e d of reaction.) 8. Because black IQ is l o w e r on average than white IQ for genetic r e a s o n s , the

IQ in c h i l d r e n of b l a c k

parents with

high

IQs

s h o u l d r e g r e s s t o a l o w e r m e a n t h a n the I Q o f c h i l d r e n o f w h i t e p a r e n t s h a v i n g the s a m e I Q s a s the b l a c k p a r e n t s . A n d i n f a c t i t does. 9. In a racial ancestry study e x a m i n i n g black, white, and mixedrace children w h o were adopted by mostly middle- and uppermiddle-class w h i t e s , the IQs of the black children differed little f r o m t h o s e o f t h e b l a c k p o p u l a t i o n a t l a r g e , a n d t h e I Q s o f t h e m i x e d - r a c e c h i l d r e n w e r e i n b e t w e e n t h o s e o f the b l a c k children a n d the w h i t e children (Scarr and W e i n b e r g ,

1983). Let's e x a m i n e these contentions in order.

1976,

Appendix

A

Heritability

211

of IQ

The Bell Curve p r e s e n t s a n a r g u m e n t t h a t s e e m s t o s e t t l e t h e r a c e and IQ debate in a simple and elegant manner. T h o s e w h o think that b l a c k s a n d whites a r e genetically identical, at least as f a r as intelligence g o e s , must believe that b l a c k s c a n be treated as if they were simply a s a m p l e of whites selected for p o o r cognitive environment. N o w if that is true, we w a n t a measure of h o w strongly environment affects IQ, which is to say we w a n t a correlation. Studies on twins supply a correlation. Herrnstein and M u r r a y a s s u m e a value that they believe to be a m i n i m u m p r o b a b l e influe n c e o f e n v i r o n m e n t o n I Q ; t h a t is, t h e y a s s u m e t h a t 6 0 p e r c e n t o f IQ variance is due to genetic differences between individuals, and 40 percent is due to environment. To get a correlation between e n v i r o n m e n t a n d I Q , we h a v e to take the s q u a r e root of the percentage of IQ variance it explains. T h e square root of .40 is .63, s o that i s the correlation w e w a n t . N o w w e can calculate h o w f a r the e n v i r o n m e n t o f the a v e r a g e b l a c k w o u l d h a v e t o b e b e l o w the e n v i r o n m e n t of the a v e r a g e w h i t e to e x p l a i n the IQ g a p of 1 SD that s e p a r a t e s the races:

1

SD divided by .63 gives us 1 . 5 9 S D s

as the necessary e n v i r o n m e n t a l d i f f e r e n c e b e t w e e n the races. In s u m , it takes that kind of e n v i r o n m e n t a l h a n d i c a p to e x p l a i n the racial IQ g a p ! H o w large this is c a n be a p p r e c i a t e d by l o o k i n g at a table of percentages under the m e a n of a n o r m a l curve. O n c e y o u reach 1 . 5 9 S D s b e l o w the m e a n , o n l y 6 p e r c e n t of the p o p u lation is l e f t — w h i c h is to say that the a v e r a g e b l a c k e n v i r o n m e n t w o u l d h a v e to be so b a d that the e n v i r o n m e n t f o r o n l y 6 percent o f A m e r i c a n w h i t e s fell b e l o w it. To Herrnstein and

M u r r a y , that w a s

implausible,

but w o r s e

w a s yet t o c o m e . J e n s e n ( 1 9 9 8 ) g a v e a m o r e u p - t o - d a t e a n a l y s i s o f t h e t w i n s t u d i e s . I t s h o w s t h a t a t a d u l t h o o d , o n l y 2.5 p e r c e n t o f IQ variance is due to environment. T h e square root of .Z5 is .50, a n d 1 SD (of IQ d i f f e r e n c e ) d i v i d e d by . 5 0 is 2. S D s . So n o w we h a v e to posit the a v e r a g e black e n v i r o n m e n t as 2. S D s b e l o w the average white environment, which

m e a n s that the e n v i r o n m e n t

APPENDIX A

212

f o r o n l y 2..2.7 p e r c e n t o f A m e r i c a n w h i t e s w o u l d f a l l b e l o w t h e a v e r a g e black e n v i r o n m e n t . T h a t is truly implausible. T h e f l a w in this a r g u m e n t is that it a s s u m e s that the environmental f a c t o r s o p e r a t i n g within g r o u p s are identical to those opera t i n g b e t w e e n g r o u p s . G e n e t i c i s t R i c h a r d L e w o n t i n illustrated this f l a w . I m a g i n e dividing a sack of seeds r a n d o m l y into t w o g r o u p s , w h i c h m e a n s that w h i l e there will be plenty of genetic variation within each g r o u p , there will

be no average genetic difference

b e t w e e n t h e g r o u p s . Y o u p u t all o f t h e s e e d s o f G r o u p A i n t o t h e s a m e i d e a l p o t t i n g m i x , a n d y o u p u t all o f t h e s e e d s o f G r o u p B into the s a m e potting m i x e x c e p t f o r each plant in G r o u p B y o u leave out one f a v o r a b l e ingredient. Clearly, within each group, height differences in plants at maturity are due to genetics—after all, there are zero e n v i r o n m e n t a l d i f f e r e n c e s within the g r o u p s . But b e t w e e n the g r o u p s , the a v e r a g e d i f f e r e n c e in height is solely d u e to an e n v i r o n m e n t a l f a c t o r , n a m e l y , the fact that o n e g r o u p is m i s s i n g a f a v o r a b l e i n g r e d i e n t i n its p o t t i n g m i x . So

now

we

seem

to

have

proved

that

twin

studies

within

g r o u p s (you h a v e no t w i n pairs of w h i c h o n e is black a n d the other white)

have no implications f o r the potency of environ-

mental f a c t o r s between g r o u p s . But there is a p r o b l e m . C a n we imagine anything in

the

real

world

analogous

to the missing

ingredient in G r o u p B's environment? It w o u l d have to be something d i s a d v a n t a g e o u s that affected every

m e m b e r of G r o u p B

equally a n d not o n e p e r s o n in G r o u p A. E v e n the effects of racism could not do that. S o m e blacks w o u l d s u f f e r f r o m poverty a n d o t h e r d i s a d v a n t a g e s m u c h less t h a n o t h e r s , a n d s o m e w h i t e s certainly s u f f e r f r o m these things m o r e than others. L e w o n t i n ' s i n g r e d i e n t w a s g i v e n t h e n a m e " f a c t o r X " t o d r a m a t i z e its m y s terious character a n d imply that no o n e could think of anything t h a t c o u l d p l a y its r o l e . Dickens solved

the

and

Flynn

problem.

(2.001) They

proposed

showed

that

a

formal

model

two groups could

that be

s e p a r a t e d by an e n v i r o n m e n t a l f a c t o r of great potency that did not a f f e c t e a c h m e m b e r o f the g r o u p s e q u a l l y . T h e y illustrated

Appendix

A

213

the p o i n t w i t h the e f f e c t s t h a t T V h a d o n the e s c a l a t i o n o f b a s ketball-playing ability. T h e n e w p o p u l a r i t y o f the g a m e m e a n t that y o u n g people played m u c h m o r e a n d d e v e l o p e d n e w technical skills, such as passing a n d s h o o t i n g w i t h b o t h right a n d left hands. W h e n g r a d u a t e s c a m e back to play their old high s c h o o l t e a m s , they w e r e s o u n d l y d e f e a t e d even t h o u g h they s u f f e r e d no genetic d i s a d v a n t a g e (they w e r e just a s tall a n d q u i c k ) .

Obvi-

ously, the n e w basketball e n v i r o n m e n t did not s e p a r a t e the t w o groups neatly; s o m e had practiced a

lot e v e n b e f o r e T V . A n d

every m e m b e r within each g r o u p w a s not a f f e c t e d t o the s a m e degree. Within an age g r o u p , those with genes that m a d e them taller a n d q u i c k e r w o u l d be m o r e likely to t a k e to b a s k e t b a l l a n d get the a d v a n t a g e of team

play

and coaching than

those w h o

w e r e short and stout. Indeed, that is the reason w h y twin studies a r e d e c e p t i v e . W i t h t h e i r i d e n t i c a l g e n e s a n d i d e n t i c a l h e i g h t and quickness, identical twins w e r e likely to have c o m m o n basketball histories—and since genes and p o w e r f u l environmental factors w e n t together, genes w o u l d get the credit for the w h o l e package. It is n o w easy to i m a g i n e a variety of e n v i r o n m e n t a l f a c t o r s that are potent a n d

that separate

black

and

white

Americans.

Different child-rearing practices, different youth cultures, and so forth could have a powerful effect on h o w much each g r o u p does " m e n t a l e x e r c i s e " a n d o n the c o g n i t i v e p r o b l e m - s o l v i n g skills they each d e v e l o p . A n d n o n e of these things has to b e h a v e like the implausible factor X. In C h a p t e r 6, I detailed the p o w e r f u l e n v i r o n m e n t a l f a c t o r s that differ greatly between blacks and whites on a v e r a g e . It can no longer be denied that such differences are c a p a b l e in principle of a c c o u n t i n g f o r the race d i f f e r e n c e in I Q . T h e f a c t that the difference between blacks and whites n o w stands at two-thirds of a standard deviation instead of at o n e s t a n d a r d deviation gives us still f u r t h e r r e a s o n t o b e l i e v e t h a t t h e d i f f e r e n c e s a r e e n v i r o n m e n tally p r o d u c e d . C e r t a i n l y the r e d u c t i o n in the d i f f e r e n c e h a s n o t h ing t o d o w i t h genetics.

APPENDIX A

214

Culture-Saturated and

Culture-Fair

IQ

Test

Items

On the s u r f a c e , the o b s e r v a t i o n that blacks score w o r s e on allegedly c u l t u r e - f a i r items than on culturally saturated

items is a

d i f f i c u l t o n e to c o u n t e r . B u t recall f r o m C h a p t e r 3 (on c h a n g i n g I Q scores o v e r time) the study b y J a m e s Flynn ( 2 0 0 0 a ) w h i c h s h o w e d that it is precisely on t h o s e IQ tests a n d subtests generally d e e m e d as

"culture fair"

that scores have increased

most

o v e r the years. F o r e x a m p l e , the gain on the allegedly culture-fair R a v e n Progressive M a t r i c e s has been e n o r m o u s , far outstripping the gain

on

more apparently culturally loaded

on subtests such

as vocabulary and

tests. T h e g a i n

information

h a s been

far

less t h a n t h a t o n a l l e g e d l y c u l t u r e - f a i r t e s t s s u c h a s b l o c k d e s i g n ( w h i c h s i m p l y i n v o l v e s m a n i p u l a t i n g g e o m e t r i c patterns) a n d the other p e r f o r m a n c e or fluid-intelligence subtests, including object a s s e m b l y a n d picture a r r a n g e m e n t . Since w e k n o w that the gains in IQ o v e r a p e r i o d as s h o r t as a g e n e r a t i o n c o u l d not possibly be

due to genetic

causes,

we

have

to

assume

that something

e n v i r o n m e n t a l is i m p r o v i n g the p e r f o r m a n c e on m o r e allegedly culture-fair subtests than on

more apparently culture-saturated

s u b t e s t s . T h u s t h e c u l t u r e - f a i r a r g u m e n t g e t s t u r n e d o n its h e a d . It is precisely the tests that we n o w k n o w to be the m o s t culturally s a t u r a t e d , such as the R a v e n a n d

block design, that most

differentiate blacks and whites.

Sub-Sabaran Africans Have IQs of 70 or 75 Let's stop and think for a m o m e n t a b o u t w h a t an IQ of 70 might m e a n , if we t o o k it seriously as an actual indicator of intelligence o f s u b - S a h a r a n b l a c k s . T h a t f i g u r e i s l o w e r t h a n t h e I Q f o r all b u t the lowest 2. percent of whites. G i v e n w h a t we k n o w a b o u t people with such l o w I Q s in o u r society, the a v e r a g e A f r i c a n , then, might n o t b e e x p e c t e d t o k n o w w h e n t o plant seeds, w h a t the f u n c tion of a chief might be, or h o w to calculate degrees of kinship. O b v i o u s l y s o m e t h i n g is desperately w r o n g with these A f r i c a n IQ

Appendix

A

215

scores. T h e y cannot possibly m e a n

f o r the A f r i c a n

population

w h a t they d o f o r people o f E u r o p e a n culture. T h e l o w s c o r e s rest p r i m a r i l y o n d a t a s u m m a r i z e d b y R i c h a r d L y n n a n d T a t u V a n h a n e n (2.002.), a n d a r e b a s e d l a r g e l y o n t h e (highly e n v i r o n m e n t a l l y responsive) R a v e n P r o g r e s s i v e M a t r i c e s . The samples

used

and haphazard.

by

Lynn

and

Vanhanen

are generally small

M o r e o v e r , they ignore s a m p l e s with

IQ means

that are relatively high (Wicherts, D o l a n , C a r l s o n , a n d van der M a a s , 2.008). T h e test s c o r e s tell u s little o r n o t h i n g a b o u t t h e actual

i n t e l l i g e n c e o f A f r i c a n s . I n s t e a d , t h e y s i m p l y tell

us that

Africans have not yet u n d e r g o n e the gain in IQ scores, especially fluid-intelligence IQ such as that m e a s u r e d by the R a v e n matrices. Consistent with this, recall f r o m C h a p t e r 3 a recent study w h i c h s h o w e d that in a particular region of K e n y a , R a v e n scores have gone up an unprecedented 1 . 7 5 S D s in a period of about fourteen years (Daley, W h a l e y , S i g m a n , E s p i n o s a , and N e u m a n n , 2.003). Also note that a few months of Western-style education increased t h e s c o r e s o f A f r i c a n s 011 f l u i d - i n t e l l i g e n c e t e s t s b y . 5 0 t o . 7 0 S D ( M c F i e , 1 9 6 1 ) , a n d even a brief training session i m p r o v e d R a v e n scores in black Africans by an a m o u n t equal to

14 IQ points

(while increasing the s c o r e s of w h i t e s by o n l y 4 points) ( S k u y et a l . , 2.002.). Herrnstein and M u r r a y ( 1 9 9 4 ) and R u s h t o n and J e n s e n (2.005) acknowledge

that

the

American

"black"

population

contains

a b o u t 2.0 p e r c e n t E u r o p e a n g e n e s ( A d a m s a n d W a r d , 1 9 7 3 ) . I n fact, they m a i n t a i n , it is f o r this r e a s o n that the A f r i c a n A m e r i c a n population has an IQ average of 85

rather than 70. Of course,

f o l l o w i n g the simplest version of this logic, if the a d m i x t u r e of E u r o p e a n genes in the black p o p u l a t i o n w e r e 40 percent instead o f 2.0,

then

African

Americans would

have an

average

IQ

of

1 0 0 — e q u a l t o t h a t o f t h e w h i t e p o p u l a t i o n — w h i c h r e q u i r e s TOO p e r c e n t E u r o p e a n g e n e s . C o n t i n u i n g t h e a r g u m e n t t o its a b s u r d conclusion, if the a d m i x t u r e of E u r o p e a n genes in the black p o p u lation w e r e 6 0 percent, then A f r i c a n A m e r i c a n s w o u l d h a v e a n average IQ of 1 1 5 !

APPENDIX A

216

Blacks Do Worse on IQ Subtests That Are Heavily g Loaded W h e n I Q rest i t e m s ( o r s u b t e s t s ) a r e s u b j e c t e d t o f a c t o r a n a l y s i s , a tool f o r d i s c o v e r i n g the w a y in w h i c h the c o r r e l a t i o n s in a m a t r i x h a n g together, the first f a c t o r extracted is called g (for general intelligence). All items (or subtests) are c o r r e l a t e d w i t h this factor. A c o n t r o v e r s y exists as to w h e t h e r g s h o u l d be regarded as a n y t h i n g m o r e t h a n a statistical necessity f o r a n y set of items that are c o r r e l a t e d a m o n g t h e m s e l v e s t o a n y degree. S o m e p e o p l e treat g a s b e i n g o f little i n t e r e s t . S o m e i n v e s t i t w i t h g r e a t s i g n i f i c a n c e a n d p o i n t t o its c o r r e l a t i o n s w i t h a n u m b e r o f p h y s i c a l a n d g e n e t i c variables, such as nerve c o n d u c t a n c e speed, as evidence that it is the principal engine of intelligence, with a substantial g r o u n d i n g in the physical nature of the n e r v o u s system. Herrnstein and M u r ray

a n

(1994)

d

R u s h t o n a n d J e n s e n (2.005) a r g u e that because

b l a c k s a n d w h i t e s d i f f e r m o r e in their p e r f o r m a n c e on items and s u b t e s t s that h a v e h i g h e r g l o a d i n g s ( c o r r e l a t i o n s w i t h the g f a c tor), this is e v i d e n c e of the b i o l o g i c a l , genetic n a t u r e of the black/ white difference in IQ. T h e first thing to note a b o u t this a r g u m e n t is that it is based primarily

on

the

loadings

of the g

factor

on

subtests

of the

Wechsler Intelligence Scale for Children ( W I S C ) . T h e differences in g l o a d i n g s on the W I S C are very slight, with the exception of a particularly l o w g l o a d i n g f o r the C o d i n g subtest. O t h e r w i s e the l o a d i n g s a r e pretty m u c h in the . 6 0 to . 7 0 r a n g e . It's scarcely impressive that there

is a c o r r e l a t i o n

between g

loadings and

b l a c k / w h i t e d i f f e r e n c e s w h e n t h e g l o a d i n g s d i f f e r s o little a m o n g themselves. Flynn g-Ioading

(2.000a)

pointed

argument

is

out

largely

that

the

based,

is

WISC, heavily

on

which

tilted

the

toward

crystallized-intelligence subtests, including Information, V o c a b u l a r y , C o m p r e h e n s i o n , A r i t h m e t i c , a n d S i m i l a r i t i e s . I f a test h a s a p r e d o m i n a n c e of subtests of o n e k i n d , the first f a c t o r e x t r a c t e d will s h o w heavy loadings f o r that kind of subtest. So if we were

Appendix

A

217

r o use a lor o f c r y s t a l l i z e d - i n r e l l i g e n c e s u b t e s t s i n o u r I Q test c o m p e n d i u m , we w o u l d get out of o u r f a c t o r analysis a first, g f a c t o r t h a t i s h e a v i l y tilted t o w a r d c r y s t a l l i z e d i n t e l l i g e n c e . But, says Flynn, suppose instead of looking at crystallized g, we were to look at fluid intelligence, or fluid g, which Jensen ( 1 9 9 8 ) and other e x p e r t s say is at least as m u c h genetically influenced as crystallized g. Fluid g is m e a s u r e d by subtests such as t h o s e requiring the s u b j e c t t o c r e a t e d e s i g n s f r o m g e o m e t r i c s h a p e s o r a r r a n g e pictures in a logical causal pattern. We can estimate the saturation of fluid g in the W I S C subtests by d e t e r m i n i n g their c o r r e l a t i o n s with

the R a v e n

Progressive

M a t r i c e s , a test t h a t , a c c o r d i n g t o

Jensen a n d other e x p e r t s in the field, is a virtually pure m e a s u r e of fluid g. We n o w correlate the fluid-^ ratings of each subtest w i t h the sort of IQ g a i n s that F l y n n h a s r e p o r t e d as o c c u r r i n g in recent decades. W h a t we find is that the higher the fluid-g loading f o r a s u b t e s t , the g r e a t e r the g a i n s in s c o r e o v e r t i m e on that subtest. We n o w have an absurdity: IQ gains, w h i c h are w i t h o u t question almost entirely e n v i r o n m e n t a l in origin, are f o u n d m o r e on subtests that are allegedly m o r e genetically influenced! T h u s by k n o w i n g a b o u t the extent to w h i c h the g a p is f o u n d f o r highly g - l o a d e d s u b t e s t s v e r s u s less ^ - l o a d e d s u b t e s t s , w e l e a r n n o t h i n g a b o u t the relative c o n t r i b u t i o n of genes a n d e n v i r o n m e n t to the black/white IQ gap. T h e g a p is bigger for highly ^-loaded subtests if we d e f i n e g as crystallized, a n d this is s u p p o s e d to s h o w that the g a p is genetic in origin. But if we d e f i n e g as f l u i d , we f i n d that the h i g h e r t h e g l o a d i n g is, t h e m o r e s u s c e p t i b l e i t i s t o e n v i r o n m e n t a l change. M o r e genetically influenced subtests c a n n o t be the ones that are the m o s t e n v i r o n m e n t a l l y i n f l u e n c e d , so it is o b v i o u s that the a r g u m e n t f r o m g l o a d i n g s is f l a w e d . F i n a l l y , as I pointed o u t in C h a p t e r 6, the c o n t e n t i o n that g loadings predict the m a g n i t u d e of b l a c k / w h i t e d i f f e r e n c e s on particular items entails the prediction that the s c o r e s on high ^ - l o a d ing items h a v e c h a n g e d the least f o r b l a c k s o v e r the past thirty years.

William

Dickens and James

Flynn

(zoo6) constructed

a

"gQ t e s t " — a n I Q s c o r e w e i g h t e d b y t h e g l o a d i n g o f e a c h s u b t e s t

218

APPENDIX A

o n the W I S C . H e r r n s t e i n a n d M u r r a y a n d R u s h t o n a n d J e n s e n w o u l d he obligated to say that even if blacks gained 5.5 points on I Q tests i n g e n e r a l , they w o u l d n o t h a v e g a i n e d v e r y m u c h o n the heavily g - l o a d e d tests. I n f a c t , h o w e v e r , b l a c k s h a v e g a i n e d 5 . 1 3 points relative to w h i t e s on items w e i g h t e d to reflect their g loadings defined as Jensen does. It s h o u l d be c o m p l e t e l y c l e a r by n o w that the ^ - l o a d i n g a r g u m e n t f o r genetically b a s e d IQ d i f f e r e n c e s b e t w e e n the races is a red herring. T h e g l o a d i n g s of subtests do not d i f f e r that m u c h , the g l o a d i n g of a p a r t i c u l a r subtest c a n n o t be c o n s t r u e d as evidence a b o u t the d e g r e e to w h i c h the subtest m e a s u r e s strictly biological or hereditary differences as opposed to environmentally produced differences, and scores for blacks have improved almost as much o n a ^ - w e i g h t e d I Q test a s o n a n o n - g - w e i g h t e d t e s t .

Blacks Do Worse on Subtests for Which Inbreeding Depression Is Relatively Great T h e a n s w e r to this c l a i m is the s a m e in f o r m as the a n s w e r to the c l a i m a b o u t g l o a d i n g s . O n t h e f a c e o f it, i f p e r f o r m a n c e o n a subtest particularly suffers f r o m inbreeding depression, and if that subtest is particularly likely to differentiate between blacks and w h i t e s , this m i g h t seem like g o o d e v i d e n c e that the black/white g a p is substantially influenced by biological, genetic factors. But it t u r n s o u t t h a t i n b r e e d i n g d e p r e s s i o n f o r subtests, like fluid-g l o a d i n g s , is a l s o c o r r e l a t e d with the e x t e n t of IQ g a i n s o v e r recent d e c a d e s ( F l y n n , z o o o a ) . In f a c t , the m a g n i t u d e of the correlation is just as great for IQ gains as for black/white differences. T h u s , we are c o n f r o n t e d with another absurdity. If we arc to believe that d e g r e e of i n b r e e d i n g d e p r e s s i o n is an i n d i c a t o r of the genetic nature of the black/white differences in intelligence, we w o u l d also h a v e to believe that degree of inbreeding depression indicates that IQ g a i n s h a v e a genetic cause. In other w o r d s , if we accept that d e g r e e of i n b r e e d i n g d e p r e s s i o n is a m e a s u r e s h o w i n g the biologi-

Appendix

A

219

cal n a t u r e o f the b l a c k / w h i t e d i f f e r e n c e , w e a l s o h a v e t o a c c e p t that d e g r e e o f i n b r e e d i n g d e p r e s s i o n s h o w s t h a t the F l y n n e f f e c t — the increase in IQ o v e r g e n e r a t i o n s — i s b i o l o g i c a l in origin.

Brain Size and the Black/White IQ Gap The correlation

between

cranial

capacity

and

IQ

is

probably

a b o u t . 3 0 - . 4 0 in the w h i t e p o p u l a t i o n ( M c D a n i e l , 2.005; Schoenemann,

Budinger,

Sarich,

and

Wang,

1999).

Rushton

and

Jensen ( 2 0 0 5 ) claim that cranial capacity for blacks is on average smaller than that for whites. A d i f f e r e n c e b e t w e e n black a n d w h i t e brain size is not a l w a y s found, however (National tion,

Aeronautics and

Space Administra-

1 9 7 8 ) . M o r e i m p o r t a n t , the correlation f o u n d within the

white population p r o b a b l y does not indicate that greater brain size c a u s e s h i g h e r I Q . W i t h i n a g i v e n f a m i l y , the s i b l i n g w i t h the larger brain has no higher IQ on a v e r a g e than the sibling with the s m a l l e r brain ( S c h o e n e m a n n , B u d i n g e r , S a r i c h , a n d W a n g , 1999)In any case, as always, within-population differences do not necessarily differences.

tell The

us

about

fact

that

the the

reasons smarter

for

between-population

people

within

p o p u l a t i o n h a v e b i g g e r c r a n i a l c a p a c i t i e s d o e s n o t tell

a

given

us that

the r e a s o n s f o r the size d i f f e r e n c e b e t w e e n b l a c k s a n d w h i t e s a r e the s a m e a s the r e a s o n s f o r the size d i f f e r e n c e s a m o n g p e o p l e o f the s a m e race w h o d i f f e r i n I Q . T h e m a l e / f e m a l e d i f f e r e n c e s in cranial capacity are substantially larger than the black/white differences ( A n k n e y , 1992.). Y e t the t w o genders h a v e the s a m e average IQ.

(It s h o u l d

be noted that IQ tests are o f t e n engi-

neered so that men a n d w o m e n c o m e out with the s a m e a v e r a g e score of 1 0 0 . But the differences in a v e r a g e scores between the s e x e s on m o s t test i t e m s a r e v e r y slight so it is not d i f f i c u l t to engineer for gender equality.)

M o r e o v e r , there exists a g r o u p

of very s h o r t - s t a t u r e i n d i v i d u a l s in E c u a d o r w h o s e h e a d size is

APPENDIX A

220

several s t a n d a r d d e v i a t i o n s b e l o w the m e a n ( G u e v a r a - A g u i r e et al., 1 9 9 1 ) . T h e s e individuals h a v e not merely n o r m a l intelligence b u t u n u s u a l l y high intelligence (with a m a j o r i t y b e i n g a m o n g the highest r a n k i n g in their school class). O n e large s a m p l e o f b l a c k s s h o w s that the cranial c a p a c i t y o f black f e m a l e s w a s the s a m e as that of w h i t e s , yet the IQ d i f f e r e n c e w a s the u s u a l s t a n d a r d d e v i a t i o n t y p i c a l o f the g a p a t the time the data w e r e collected (Joiner, in press). T h e IQ difference therefore is f o u n d in the a b s e n c e of a c r a n i a l - c a p a c i t y d i f f e r e n c e . Finally, it is likey that the brain-size differences between blacks and

whites that are sometimes found are environmental

than

genetic

in

origin

(Ho,

Roessmann,

Hause, and

rather

Monroe,

1 9 8 1 ) . P r e g n a n t black w o m e n a r e m o r e likely t o h a v e a n y n u m ber of c o n d i t i o n s t h a t c a n result in s m a l l e r size of b o t h b o d y a n d brain, r a n g i n g f r o m p o o r nutrition to alcohol use, than are white w o m e n . Perinatal factors are also much m o r e negative for blacks in general than f o r whites ( B a k a l a r , 2.007); and prematurity is associated with m u c h l o w e r brain size, especially f o r black babies ( H o et al.,

1 9 8 1 ) It is o n l y w h e n b a b i e s are p r e m a t u r e that the

brains of black babies are smaller than those of white babies ( H o et al.,

1 9 8 1 ) Postnatal conditions also favor whites over blacks,

especially for nutrition (Ho, R o e s s m a n n , Straumfjord, and M o n roe,

1980).

So we do not learn m u c h that is very c o m p e l l i n g f r o m the fact that

blacks are sometimes

found

to have smaller brains than

whites. Correlations within populations should not be extrapolated

to

between-population differences, and

in a n y case, the

within-population differences m a y not be due to greater brain size b e i n g c a u s a l l y related to h i g h e r I Q .

Reaction More

Times Are Slower for Blacks

intelligent

people

in

the

white

population

have quicker

r e a c t i o n t i m e s t h a n d o less i n t e l l i g e n t p e o p l e . I n a d d i t i o n , t h e v a r i a b i l i t y of the r e a c t i o n t i m e s f o r h i g h e r - I Q p e o p l e is less, m e a n i n g

Appendix

A

221

that the reaction times of h i g h e r - I Q p e o p l e are m o r e u n i f o r m than t h o s e o f less i n t e l l i g e n t p e o p l e . T h e c o r r e l a t i o n s w i t h I Q a r e l o w — a r o u n d .2.0 ( D e a r y , 2 . 0 0 1 ) — a n d a r e n o t a l w a y s f o u n d , b u t t h e b e s t bet i s t h a t t h e r e a r e w e a k a s s o c i a t i o n s . A n d r e a c t i o n t i m e s a n d variability of reaction times are longer and greater, respectively, for blacks than for whites ( R u s h t o n a n d J e n s e n , 2.005). O n c e a g a i n , let u s n o t e f i r s t o f all t h a t , a s f o r b r a i n s i z e a n d any other v a r i a b l e associated with IQ within a p o p u l a t i o n , the b e t w e e n - p o p u l a t i o n differences do not necessarily h a v e the s a m e c a u s e a s the w i t h i n - p o p u l a t i o n c o r r e l a t i o n s .

M o r e o v e r , reaction

t i m e i n c r e a s e s v e r y little a f t e r t h e a g e o f e l e v e n , b u t i n t e l l i g e n c e keeps on g r o w i n g apace (Nettelbeck,

1998). A n d some mentally

retarded people h a v e e x t r e m e l y fast reaction times (Flynn, 2.007). But these c a v e a t s a r e the least o f the p r o b l e m s f o r the a r g u m e n t for

black

intellectual

First o f all,

both

inferiority

Herrnstein

and

based

on

Murray

slow

reaction

(1994)

and

times.

Rushton

and Jensen ( 2 0 0 5 ) maintain that A s i a n s h a v e slightly higher IQs than w h i t e s , a n d both sets o f a u t h o r s i m p l y that the r e a s o n s f o r that d i f f e r e n c e m a y be at least partially genetic. In R u s h t o n a n d Jensen's Table (2002.), we

1, drawn

learn

from a

book

by Lynn and Vanhanen

that a s a m p l e of H o n g K o n g subjects has an

average IQ of i 13 and a s a m p l e of J a p a n e s e subjects has an avera g e I Q o f 1 TO. ( T h e s e e s t i m a t e s a r e m u c h h i g h e r t h a n w h a t i s c o m m o n l y r e p o r t e d i n the literature, i n c i d e n t a l l y , a n d recall f r o m C h a p t e r 8 that the e v i d e n c e indicates East A s i a n s do n o t h a v e a higher IQ than Westerners.) T h e East Asians also have shorter a n d less v a r i a b l e r e a c t i o n t i m e s t h a n d o t h e o t h e r g r o u p s o f w h i t e s and blacks included in the table. H o w e v e r , J e n s e n (with W h a n g , * 9 9 3 ) reported that the reaction times a n d variabilities in a g r o u p of Chinese Americans were longer and greater, respectively, than those in a g r o u p of E u r o p e a n A m e r i c a n s , even t h o u g h the s a m e Chinese Americans had an average IQ that w a s 5 points higher than that f o r the E u r o p e a n A m e r i c a n s . A n d L y n n a n d S h i g h e s i a ( 1 9 9 1 ) reported that a l t h o u g h the reaction times in a g r o u p of J a p a n e s e w e r e faster than those in a g r o u p of British subjects, the

APPENDIX A

222

J a p a n e s e h a d higher variabilities. Flynn ( 1 9 9 1 b ) reported that it w a s m o v e m e n t time and not reaction time that correlated with IQ f o r the C h i n e s e subjects. M o v e m e n t time is a m e a s u r e of h o w long it t a k e s a p e r s o n to m o v e a f i n g e r f r o m the starting position a f t e r h e h a s m a d e t h e d e c i s i o n t o m o v e it. A c r o s s a h o s t o f s t u d i e s , m o v e m e n t times are just as highly correlated with IQ as reaction times ( D e a r y , 2.001). A n d blacks have faster m o v e m e n t times than do whites!

Rushton and Jensen (2005) do not mention any of

these c o m p l i c a t i o n s to their simple reaction-time and race story. In a d d i t i o n , the d i f f e r e n c e s b e t w e e n the b l a c k S o u t h A f r i c a n s a n d the Irish r e p o r t e d b y L y n n a n d V a n h a n c n are h u g e f o r I Q but trivial for reaction times. In short, the overall results are a mess for t h e s e t o f c o n t e n t i o n s t h a t (a) m e a n r e a c t i o n t i m e a n d v a r i a b i l i t y i n r e a c t i o n t i m e a r e c o r r e l a t e d w i t h I Q , b u t (b) m o v e m e n t t i m e i s n o t c o r r e l a t e d w i t h I Q , a n d (c) r e a c t i o n t i m e s b u t n o t m o v e m e n t t i m e s a r e f a s t e r f o r A s i a n s t h a n t h e y a r e f o r w h i t e s , a n d (d) r e a c tion times a r e faster f o r w h i t e s than they are f o r blacks but their m o v e m e n t times are slower than those of blacks. T h e reasonable p o s i t i o n at this point is to a s s u m e that we k n o w n o t h i n g of any clarity

or

value

a b o u t the

interrelations

among

reaction

time,

m o v e m e n t time, and race.

Black IQ Regresses to a Lower Mean than White IQ H e r e d i t a r i a n s o f t e n c l a i m t h a t b e c a u s e I Q i s l o w e r 011 a v e r a g e f o r b l a c k s than for w h i t e s f o r genetic reasons, the IQ of children of black parents with high I Q s should regress to a l o w e r mean than the IQ of the children of w h i t e p a r e n t s h a v i n g the s a m e IQ as the black parents. In o t h e r w o r d s , high I Q s f o r b l a c k s are farther f r o m the g e n o t y p i c a v e r a g e of the black distribution than c o m p a r a b l y high I Q s f o r w h i t e s are f r o m the g e n o t y p i c a v e r a g e of the white distribution, so the I Q s f o r children of high-IQ blacks have farther to d r o p on a v e r a g e than do the I Q s f o r children of high-IQ whites. A n d it a p p a r e n t l y is the c a s e that the children of h i g h - I Q b l a c k s h a v e l o w e r a v e r a g e I Q s than do the children of c o m p a r a b l y high-IQ

Appendix

A

223

whites. T h i s a r g u m e n t is quite w e a k because the s a m e prediction can be derived

f r o m an environmental theory.

If environmental

factors such as parenting practices and subculture pressures t o w a r d l o w intellectual p e r f o r m a n c e s a r e p u s h i n g the a v e r a g e black

IQ

d o w n m o r e than the a v e r a g e w h i t e I Q , then w e w o u l d a l s o e x p e c t regression to a l o w e r m e a n f o r the o f f s p r i n g of h i g h - I Q b l a c k s — f o r reasons having nothing to do with genetics.

Racial Ancestry and IQ All of the research r e p o r t e d a b o v e is m o s t c o n s i s t e n t w i t h

the

proposition that the genetic c o n t r i b u t i o n to the black/white difference is nil, but the e v i d e n c e is not terribly p r o b a t i v e o n e w a y or the other because it is indirect. T h e only direct evidence on the question of genetics c o n c e r n s the racial a n c e s t r y of a given individual. T h e genes i n the U . S . " b l a c k " p o p u l a t i o n are a b o u t 2 0 percent E u r o p e a n (Parra et al., 1 9 9 8 ; Parra, Kittles, and Shriver, Z004). Some blacks have completely African ancestry, many have a t least s o m e E u r o p e a n a n c e s t r y , a n d s o m e — a b o u t

10 percent—

have mostly European ancestry. Does it m a k e a difference h o w A f r i c a n v e r s u s E u r o p e a n a b l a c k p e r s o n is? A h e r e d i t a r i a n m o d e l d e m a n d s that blacks with m o r e E u r o p e a n genes have higher IQs. Herrnstein and M u r r a y ( 1 9 9 4 ) and Rushton and Jensen ( 2 0 0 5 ) , as it h a p p e n s , scarcely deal w i t h this direct e v i d e n c e .

Children of different racial ancestry adopted into white families. Herrnstein and M u r r a y ( 1 9 9 4 ) and

Rushton and Jensen

(2.005)

reported on a study by Scarr and Weinberg ( 1 9 8 3 ) s h o w i n g that black children adopted by white families have a l o w e r average IQ than white children a d o p t e d by white families, with m i x e d - r a c e adoptees having an average IQ in

between. U n d e r the simplest

m o d e l o f p u r e g e n e t i c d e t e r m i n a t i o n o f the b l a c k / w h i t e I Q g a p , the w h i t e a d o p t e e s s h o u l d h a v e h a d a n a v e r a g e I Q 1 5 p o i n t s o r s o higher than the a v e r a g e f o r black a d o p t e e s . T h e a v e r a g e f o r m i x e d - r a c e a d o p t e e s s h o u l d fall in the middle. W h e n the children w e r e a b o u t seven y e a r s old, their I Q s w e r e m o s t consistent with a

APPENDIX A

224

m o d e l of a very slight genetic c o n t r i b u t i o n to the g a p . W h e n they w e r e a d o l e s c e n t s , their I Q s suggested a larger genetic contribution (Weinberg, Scarr, a n d W a l d m a n , 1992.). Scarr a n d W e i n b e r g ( 1 9 8 3 ) identified several factors that m a d e t h e i r s t u d y a w e a k test o f t h e g e n e t i c h y p o t h e s i s . F i r s t , a d o p t i o n agencies may have engaged

in selective placement, which could

h a v e h a d the e f f e c t of p u t t i n g the black a d o p t e e s into families that w e r e of relatively l o w e r social class. S e c o n d , since the n a t u r a l parents' I Q s w e r e not k n o w n , it is possible that the natural parents of the w h i t e c h i l d r e n h a d higher ( g e n o t y p i c ) I Q s than the w h i t e p o p u lation in g e n e r a l , or the n a t u r a l p a r e n t s of the black children had l o w e r g e n o t y p i c I Q s than the black p o p u l a t i o n at large, w h i c h by itself c o u l d e x p l a i n w h y t h e w h i t e a d o p t e e s h a d a h i g h e r a v e r a g e I Q than the black adoptees. T h i r d , the black children w e r e a d o p t e d at a s u b s t a n t i a l l y l a t e r a g e t h a n t h e w h i t e c h i l d r e n , a n d late a d o p t i o n has n e g a t i v e i m p l i c a t i o n s f o r I Q . F o u r t h , the black children had more prior placements in foster homes, which is also associated w i t h l o w e r I Q . F i f t h , t h e p r e a d o p t i v e p l a c e m e n t s o f the b l a c k children w e r e w o r s e . S i x t h , S a n d r a Scarr told me that the adolescent black and interracial children had an unusual degree of psychological d i s t u r b a n c e h a v i n g t o d o with identity issues. S o m e children r e p o r t e d , i n e f f e c t , " I l o o k i n t h e m i r r o r a n d I ' m s h o c k e d t o see a black person because I k n o w I'm really w h i t e . " O t h e r children w e r e d i s t u r b e d b e c a u s e they felt that they w e r e really black and d i d n ' t k n o w w h y they had been c o n s i g n e d to an alien w h i t e f a m i l y . As a c o n s e q u e n c e o f all t h e s e p r o b l e m s , t h e a u t h o r s c a u t i o n e d a g a i n s t a n y c o n c l u s i o n w i t h respect to the role of heredity in intelligence f o r adolescents. In a n y c a s e , as we will n o w see, the S c a r r a n d W e i n b e r g study is the sole r a c i a l - m i x t u r e study that g i v e s a n y s u p p o r t to the hypothesis that E u r o p e a n genes m a k e a " b l a c k " person smarter.

Black and white children Another study on

raised in an enriched environment.

black and white children

raised

in the s a m e

environment reached very different conclusions f r o m those reached b y Herrnstein a n d M u r r a y ( 1 9 9 4 ) a n d R u s h t o n a n d J e n s e n (2.005) on the basis of the S c a r r - W e i n b e r g study. T h i s study w a s of black.

Appendix

A

225

white, and mixed-race children raised in an excellent institutional setting ( T i z a r d , C o o p e r m a n , a n d T i z a r d ,

1 9 7 1 ) . The caretakers

w e r e particularly well trained a n d c o n s c i e n t i o u s , a n d the c h i l d r e n ' s d a y s were structured a r o u n d highly intellectually stimulating activities. A t f o u r o r f i v e y e a r s o l d , w h i t e c h i l d r e n h a d a n a v e r a g e I Q o f 1 0 3 , black children had an average of 1 0 8 , and children of mixed race had an a v e r a g e of 1 0 6 . On their f a c e , these results a r e m o s t c o m p a t i b l e w i t h the a s s u m p t i o n of a nontrivial genetic a d v a n t a g e f o r blacks. T h e black children i n this s t u d y w e r e W e s t Indian a n d the white children w e r e English. W h i l e it is possible that the black parents had unusually high g e n o t y p i c I Q s , F l y n n ( 1 9 8 0 ) a r g u e d that selective m i g r a t i o n of W e s t Indians to Britain c o u l d not h a v e raised IQ scores by m o r e than a very f e w points. N e v e r t h e l e s s , like the S c a r r - W e i n b e r g s t u d y , this o n e s u f f e r s f r o m the f a c t that w e d o not k n o w the I Q s o f the n a t u r a l p a r e n t s .

Black children adopted by black or by white families. A n o t h e r a d o p t i o n study had a design that w a s d i f f e r e n t f r o m the ScarrW e i n b e r g s t u d y , a n d s e e m s c l e a r l y s u p e r i o r t o it. T h e s t u d y g r o u p s were black and mixed-race children raised in either black or white middle-class adoptive families ( M o o r e , 1 9 8 6 ) . Black and biracial children raised by blacks had similar I Q s , and so did black and biracial children raised by whites. T h u s , having E u r o p e a n genes w a s no a d v a n t a g e to the a d o p t e d children in either e n v i r o n m e n t . R u s h t o n a n d J e n s e n ( 2 0 0 5 ) try t o d i s m i s s this s t u d y b e c a u s e the children w e r e only seven y e a r s old at the time of testing. T h e y say that " a s p e o p l e age, their g e n e s e x e r t ever m o r e influence, w h e r e a s f a m i l y s o c i a l i z a t i o n e f f e c t s d e c r e a s e (see F i g u r e 3 ) . T r a i t differences n o t a p p a r e n t early in life begin to a p p e a r at p u b e r t y a n d a r e c o m p l e t e l y a p p a r e n t b y a g e 1 7 " ( p . 2.59). T h e i r F i g u r e 3 , h o w e v e r , s h o w s nearly identical heritability at ages seven a n d seventeen, so their o w n evidence refutes the idea that we can ignore M o o r e ' s f i n d i n g o f 110 d i f f e r e n c e b e t w e e n I Q s i n b l a c k a n d b i r a cial children. M o r e generally, there is plenty of evidence s h o w i n g significant heritability of IQ by age seven, so the finding of no race difference at that a g e is quite telling.

APPENDIX A

226

T h e M o o r e s t u d y ( 1 9 8 6 ) p r o v i d e s a n o t h e r test o f e n v i r o n m e n tal

versus genetic

hypotheses.

Under

the a s s u m p t i o n

that race

d i f f e r e n c e s i n I Q a r e l a r g e l y g e n e t i c , i t s h o u l d m a k e little d i f f e r ence whether black or m i x e d - r a c e children are raised by black or w h i t e families. U n d e r the a s s u m p t i o n that it m a k e s a great deal of difference what kind of home, neighborhood, and school environment children g r o w up in, it should m a k e a substantial difference whether the children w e r e raised in black or white families. T h u s , even t h o u g h both the black a n d the white a d o p t i v e families w e r e m i d d l e class, the i n v e s t i g a t o r e x p e c t e d that the children raised in w h i t e f a m i l i e s w o u l d h a v e the h i g h e r I Q s . A n d indeed this w a s the case. Children raised by blacks had an a v e r a g e IQ of 1 0 4 , w h e r e a s t h o s e raised b y w h i t e s h a d a n a v e r a g e I Q o f 1 1 7 . A l t o g e t h e r the study provided no evidence consistent with a genetic contribution to the black/white g a p in the p o p u l a t i o n at large, a n d substantial reason to believe that the g a p is largely or entirely environmental in nature. O n c e a g a i n , t h o u g h , the missing key is the k n o w l e d g e of the I Q s of the n a t u r a l p a r e n t s . ( A n d the n u m b e r of s u b j e c t s — forty-six—is lower than desirable.) As it happens, there are additional studies that allow us to assess, even m o r e directly than the a d o p t i o n studies d o , the question of the effects of E u r o p e a n versus A f r i c a n ancestry. A n y given m e m b e r of the b l a c k p o p u l a t i o n in the U n i t e d States c o u l d h a v e anywhere

between

European genes. of blacks?

Five

1 0 0 percent West African genes and mostly

Are European genes g o o d qualitatively

different

kinds

f o r the intelligence of studies

provide

a n s w e r s t o this q u e s t i o n . Studies

of skin

color.

Studies

relating

darkness

of s k i n

color

a n d I Q are easy t o d o , a n d m a n y h a v e been r e p o r t e d o v e r the years. L e t ' s p a u s e a m o m e n t a n d think a b o u t w h a t the c o r r e l a t i o n b e t w e e n skin c o l o r a n d IQ might be in the black p o p u l a t i o n under the a s s u m p t i o n of a purely e n v i r o n m e n t a l c a u s e of the black/white IQ gap.

We w o u l d e x p e c t lighter skin to be associated with a

greater a d v a n t a g e for A f r i c a n A m e r i c a n s , resulting in higher SES and the educational and environmental a d v a n t a g e s that go along

Appendix

A

227

w i t h it. T h u s , w e w o u l d e x p e c t a p o s i t i v e c o r r e l a t i o n , p e r h a p s a s high a s . z o o r . 3 0 o r even m o r e , b e t w e e n skin c o l o r a n d I Q . I n fact, h o w e v e r , the literature consistently s h o w s that the c o r r e l a t i o n of IQ with skin color in the black p o p u l a t i o n is quite l o w . E v e n A u d r e y S h u e y ( 1 9 6 6 ) , o n e of the m o s t v e h e m e n t s u p p o r t e r s of the v i e w that the b l a c k / w h i t e IQ g a p is genetic in o r i g i n , r e a c h e d the conclusion that IQ is only very w e a k l y associated with skin color. T y p i c a l correlations are in the range of . 1 0 to . 1 5 . C o r r e l a t i o n s b e t w e e n IQ a n d the d e g r e e to w h i c h facial f e a t u r e s a r e rated as stereotypically African are similarly low (Shuey,

1 9 6 6 ) . Even if

w e ignore the a d v a n t a g e s that m i g h t a c c r u e t o b l a c k s w i t h light skin, a correlation of . 1 0 does not suggest that E u r o p e a n ancestry exerts a strong genetic influence on IQ. On the other h a n d , m a n y o f the studies S h u e y r e v i e w e d had small s a m p l e s a n d d u b i o u s s a m pling procedures. Both skin color and IQ are m e a s u r e d with high reliability, but a m a j o r p r o b l e m with these studies is that while skin c o l o r m a y seem to be a s t r a i g h t f o r w a r d indicator of degree of E u r o p e a n ancestry, it is not. Skin c o l o r varies substantially in sub-Saharan A f r i c a n populations. As a result, s o m e A f r i c a n s have relatively light skin f o r reasons that h a v e n o t h i n g t o d o w i t h E u r o p e a n a n c e s t r y . A s t r o n g test o f t h e " E u r o p e a n a n c e s t r y " h y p o t h esis t h e r e f o r e requires a m o r e reliable i n d i c a t o r .

Studies

measuring European

ancestry

via

blood-group

indica-

tors. F o r t u n a t e l y , t h e r e a r e d a t a a v a i l a b l e t h a t r e i n f o r c e t h e n u l l implications o f the s k i n - c o l o r studies. T h e f r e q u e n c y o f d i f f e r e n t blood g r o u p s varies by race. S o m e b l o o d g r o u p s that are c o m m o n in Fluropean p o p u l a t i o n s are rare in A f r i c a n p o p u l a t i o n s a n d vice versa. Under the genetic hypothesis, blacks with m o r e " E u r o p e a n " blood groups should have more European genes and hence higher IQs. But S c a r r , Pakstis, K a t z , a n d B a r k e r ( 1 9 7 7 ) f o u n d that the correlation between IQ and degree of E u r o p e a n heritage a m o n g blacks w a s only .05

in a sample of 1 4 4 black adolescent twin

pairs. When skin color and s o c i o e c o n o m i c status were controlled, the correlation d r o p p e d slightly, to - . 0 2 . It is i m p o r t a n t to note that these researchers f o u n d a typical correlation of . 1 5 between

APPENDIX A

228

skin c o l o r a n d I Q , s u g g e s t i n g that the c o m p a r a b l e c o r r e l a t i o n s in other studies w e r e due not to slight superiority of E u r o p e a n genes but to s o m e o t h e r f a c t o r a s s o c i a t e d w i t h light skin c o l o r in the black population such as social advantage. L o e h l i n and colleagues ( 1 9 7 3 ) correlated the estimated Europeanness

of

blood

groups

(rather

than

the

Europeanness

of

individuals, estimated f r o m their blood g r o u p s ) with IQ in t w o different, small samples of blacks. T h e y found a .01

correlation

i n o n e s a m p l e a n d a n o n s i g n i f i c a n t —.38 c o r r e l a t i o n i n t h e o t h e r s a m p l e , with the m o r e A f r i c a n b l o o d g r o u p s being associated with the higher I Q s . It s h o u l d be noted, h o w e v e r , that the b l o o d - g r o u p studies are n o t a s d e f i n i t i v e a s t h e y m i g h t s e e m 011 t h e s u r f a c e . T h i s h a s t o d o w i t h technical reasons related to the fact that white b l o o d genes a r e o n l y very w e a k l y , if at all, a s s o c i a t e d w i t h o n e a n o t h e r in the black p o p u l a t i o n . If n o t a s s o c i a t e d w i t h o n e a n o t h e r , then they m i g h t a l s o n o t be a s s o c i a t e d w i t h the w h i t e genes that are determinative of IQ.

Children born to black and white American soldiers in War

II.

A

German

IQs of several fathered

by

psychologist

hundred

(Eyferth,

1961)

World

studied

the

illegitimate children of G e r m a n w o m e n

b l a c k A m e r i c a n G I s d u r i n g the p o s t - 1 9 4 5

occupa-

tion, and c o m p a r e d them to those fathered by white GIs. Again, take a m o m e n t to do a t h o u g h t e x p e r i m e n t here. We k n o w there w a s very substantial

prejudice against the mixed-race children,

since it w o u l d h a v e been o b v i o u s that they had been fathered illegitimately

by

foreign

soldiers.

We thus

would

expect, even

under the hypothesis of zero genetic contribution to black/white IQ d i f f e r e n c e s , that the m i x e d - r a c e children w o u l d h a v e suffered d i s a d v a n t a g e s that c o u l d h a v e contributed to a l o w e r IQ. But in fact the children fathered by black G I s had an a v e r a g e IQ of 9 6 . 5 a n d the c h i l d r e n f a t h e r e d b y w h i t e G I s h a d a n a v e r a g e I Q o f 9 7 . I n a s m u c h as the ( p h e n o t y p i c ) b l a c k / w h i t e IQ g a p in the military as a w h o l e w a s close to that in the general p o p u l a t i o n , these data imply that the black/white g a p in the U.S. p o p u l a t i o n as a w h o l e

Appendix

A

229

is not genetic in origin ( F l y n n , 1 9 8 0 , p p . 87—88). T h e s e d a t a a l s o are not quite as p r o b a t i v e as might a p p e a r on the s u r f a c e , because the A r m y

used

a cutoff for IQ

in accepting soldiers and

that

cutoff excluded a higher portion of blacks than whites, meaning that b l a c k s w e r e a n u n r e p r e s e n t a t i v e l y elite g r o u p . F l y n n ( 1 9 8 0 ) estimated that this c o u l d h a v e p r o d u c e d no m o r e than a 3 - p o i n t difference in IQ between the black A r m y p o p u l a t i o n g e n o t y p e a n d the genetic c o m p o s i t i o n of the black p o p u l a t i o n as a w h o l e , a n d p r o b a b l y less, but that l o o p h o l e m e a n s that the s t u d y results a r e less t h a n d e f i n i t i v e . (It s h o u l d b e n o t e d t h a t s o m e o f t h e c h i l d r e n w e r e t h o s e o f N o r t h A f r i c a n t r o o p s . F l y n n ( 1 9 8 0 ) , h o w e v e r , estim a t e d that this c o u l d a f f e c t e x p e c t a t i o n s a b o u t the I Q o f c h i l d r e n born to soldiers of color by only a very small a m o u n t — u n l e s s one a s s u m e s that the a v e r a g e g e n o t y p i c I Q f o r the N o r t h A f r i c a n soldiers w a s far higher than that k n o w n f o r any military g r o u p . ) Effect of white ancestry.

A third a p p r o a c h

to e s t i m a t i n g b l a c k s '

white ancestry is to ask them a b o u t their f a m i l y history. I m a g i n e a 1 5 - p o i n t black/white d i f f e r e n c e in IQ that is largely genetic in origin. T h e n think of f o u r g r o u p s of blacks: one has only A f r i c a n ancestry, one has m o r e African than white ancestry, one has equal African and white ancestry, and one has more white than African ancestry. U n d e r the a s s u m p t i o n of any c o n t r i b u t i o n of genetics to the b l a c k / w h i t e IQ d i f f e r e n c e , those g r o u p s s h o u l d d i f f e r in I Q . If we singled out blacks of particularly high I Q , we w o u l d e x p e c t to find that a very d i s p r o p o r t i o n a t e n u m b e r of them w o u l d h a v e substantial white ancestry. Witty and Jenkins ( 1 9 3 4 , black

Chicago

1936)

schoolchildren

identified f r o m a sample of

sixty-three

with

IQs

of

12.5

or

a b o v e and twenty-eight with I Q s o f 1 4 0 o r a b o v e . O n the basis of their self-reports a b o u t a n c e s t r y , the i n v e s t i g a t o r s c l a s s i f i e d the children into the f o u r categories of E u r o p e a n n e s s just described. T h e children with I Q s o f 12.5 o r a b o v e , a s well a s those w i t h I Q s o f 1 4 0 o r a b o v e , h a d s l i g h t l y less E u r o p e a n a n c e s t r y t h a n t h e b e s t estimate f o r the A m e r i c a n black p o p u l a t i o n as a w h o l e at the time. T h i s study w a s not ideal. It w o u l d have been better to c o m p a r e the

APPENDIX A

230

d e g r e e of E u r o p e a n ancestry in h i g h - I Q C h i c a g o children to that of o t h e r black C h i c a g o children rather than to the entire black p o p u l a t i o n . But o n c e again the results are consistent with a model of zero genetic contribution to the black/white g a p o r , perhaps, a slight genetic a d v a n t a g e for A f r i c a n s .

Mixed-race

children

horn

to

white

versus

black

mothers.

If the black/white IQ g a p is largely genetic, children of m i x e d p a r e n t a g e s h o u l d h a v e the s a m e a v e r a g e I Q regardless o f w h i c h parent is b l a c k , since there is no a priori reason to a s s u m e that the g e n o t y p e s of the black m o t h e r / w h i t e f a t h e r children and the white mother/black father children would be different. (Though it s h o u l d be n o t e d that black f a t h e r s in the s t u d y h a d s o m e w h a t higher

education

generally,

and

which could

occupational have

levels

than

did

black

m e a n t that the g e n o t y p e s

men

f o r the

children of white mothers and black fathers w e r e slightly superior to those f o r the children of black m o t h e r s and white fathers.) But i f (a) m o t h e r s a r e m o r e i m p o r t a n t t h a n f a t h e r s t o t h e i n t e l l e c t u a l socialization of their children, a n d if the socialization practices of w h i t e s f a v o r the a c q u i s i t i o n of skills that result in high IQ scores, a n d / o r (b) if the c h i l d ' s p e e r s are m o r e likely to be w h i t e if the m o t h e r is w h i t e , then the children of w h i t e m o t h e r s a n d black fathers should score higher than the children of black mothers a n d white fathers. In fact, a study by Willerman and colleagues ( 1 9 7 4 ) f o u n d that children of white mothers and black fathers had a 9-point IQ a d v a n t a g e over those of black mothers and white f a t h e r s . T h i s r e s u l t s u g g e s t s t h a t m o s t i f n o t all o f t h e b l a c k / w h i t e I Q g a p i s e n v i r o n m e n t a l (but n o t e that the c h i l d r e n tested w e r e only four years old, an age at which IQ scores predict adult IQ scores only modestly). S o w h a t d o w e h a v e i n the w a y o f studies that e x a m i n e the effects of racial a n c e s t r y — b y far the m o s t direct w a y to assess the c o n t r i b u t i o n of genes versus the e n v i r o n m e n t to the black/white IQ g a p ? W e h a v e o n e f l a w e d a d o p t i o n study with results consistent with the h y p o t h e s i s that the g a p is substantially genetic in origin, a n d w e h a v e t w o l e s s - f l a w e d a d o p t i o n s t u d i e s , o n e o f w h i c h indi-

Appendix

A

231

cates slightly s u p e r i o r A f r i c a n g e n e s a n d o n e of w h i c h

suggests

no genetic difference. We have dozens of studies l o o k i n g at racial ancestry as indicated by skin color and " n e g r o i d n e s s " of features that p r o v i d e scant s u p p o r t f o r the genetic t h e o r y . In a d d i t i o n , three different studies of E u r o p e a n n e s s of blood g r o u p s , using t w o different designs, indicate n o s u p p o r t f o r the genetic t h e o r y . O n e study of illegitimate children in G e r m a n y d e m o n s t r a t e s no superiority for children of white fathers as c o m p a r e d to children of black fathers. O n e study s h o w s that exceptionally bright " b l a c k " children have no m o r e E u r o p e a n ancestry than the best-available estimate for the p o p u l a t i o n as a w h o l e . A n d o n e s t u d y indicates that it is m o r e a d v a n t a g e o u s for a m i x e d - r a c e child to be raised by a f a m i l y h a v i n g a w h i t e m o t h e r t h a n by a f a m i l y h a v i n g a b l a c k m o t h e r . All of these racial ancestry studies are subject to alternative interpretations. M o s t of these a l t e r n a t i v e s boil d o w n to the p o s sibility that there w a s self-selection f o r IQ in b l a c k - w h i t e u n i o n s . If whites w h o mated with blacks had much lower IQs than whites i n g e n e r a l , t h e i r E u r o p e a n g e n e s w o u l d c o n v e y little I Q a d v a n t a g e . Similarly, if blacks w h o mated with whites had much higher IQs than blacks in g e n e r a l , their A f r i c a n g e n e s w o u l d not h a v e been a d r a w b a c k . Y e t the extent to w h i c h w h i t e g e n e s c o n t r i b u t i n g to mixed-race unions would have to be inferior to white genes in general, or black genes would have to be superior to black genes in general, w o u l d h a v e to be very e x t r e m e to result in no IQ d i f f e r e n c e a t all b e t w e e n c h i l d r e n o f p u r e l y A f r i c a n h e r i t a g e a n d t h o s e of partially E u r o p e a n origin. M o r e o v e r , self-selection by IQ w a s p r o b a b l y not very great d u r i n g the slave era, w h e n m o s t blackwhite unions probably took place. It is unlikely, for e x a m p l e , that the w h i t e males w h o m a t e d with black f e m a l e s had on a v e r a g e a lower IQ than other white males. Indeed, if such unions mostly involved white male slave-owners and black female slaves, which seems likely to be the c a s e (Parra et al.,

1 9 9 8 ) , and if e c o n o m i c

status w a s slightly p o s i t i v e l y related to IQ (as it is n o w ) , these whites p r o b a b l y had I Q s slightly a b o v e a v e r a g e . T h e black f e m a l e partners w e r e not likely c h o s e n on the basis of I Q , as o p p o s e d to

APPENDIX A

232

comeliness. Similarly, it scarcely seems likely that either black or white soldiers in World War II were selecting their German mates on the basis of IQ. Several studies, moreover, are immune to the self-selection hypothesis. In particular, the study involving black and white children raised in an institutional setting, and the study involving black children adopted into either black or white middle-class homes, could not be explained by self-selection for IQ in mating. In short, though one would never know it by reading Hermstein and Murray's book ( 1 9 9 4 ) or Rushton and Jensen's article ( Z 0 0 5 ) , the great mass of evidence on racial ancestry—the only direct evidence we have—points toward no contribution at all of genetics to the black/white gap.

IQ

Gains for Blacks?

Despite this strong evidence against the genetic hypothesis, we would be reluctant to abandon it totally if there were no evidence of IQ gains in the past generation or so. Things have improved both materially and socially for blacks, what with the civil rights movement, affirmative action, the increase in the proportion of blacks who are middle class, and the fact that blacks have penetrated into the highest levels of the society (including a chairman of the Joint Chiefs of Staff, two secretaries of state, a serious candidate for the presidency, C E O of the largest media company in the world, and C E O of one of the largest brokerage houses in the world). Have these changes been accompanied by increases in IQ for the average black? The answer offered by Rushton and Jensen in their 2 0 0 5 article is that they have not. The difference, they maintain, has been steady for nearly one hundred years at 1.1 SDs, or approximately 1 6 . 5 points. But William Dickens and James Flynn ( 2 . 0 0 6 ) have shown that between 1 9 7 2 . and 2 : 0 0 2 . , the I Q gap between American blacks and American non-Hispanic whites decreased by 4.5 to 7 . 0 points when they were tested before the age of twenty-five (the range

Appendix

A

233

b e i n g d e p e n d e n t o n t h e t y p e o f test u s e d ) . T h e v a l u e D i c k e n s a n d Flynn p r e f e r is 5 . 5 p o i n t s . As I noted in C h a p t e r 3, tests h a v e to be restandardized f r o m time to time because they b e c o m e o u t d a t e d . T o t h e e x t e n t p o s s i b l e , t e s t e r s try t o o b t a i n r a n d o m s a m p l e s o f t h e p o p u l a t i o n f o r their s t a n d a r d i z a t i o n studies. D i c k e n s a n d Flynn analyzed data f r o m nine s t a n d a r d i z a t i o n s of f o u r of the m o s t c o m m o n l y used I Q tests, o n e s they b e l i e v e p r o v i d e the m o r e v a l i d estimates of t e m p o r a l c h a n g e s in the IQ g a p : the W I S C , the W e c h s l e r A d u l t Intelligence S c a l e , the S t a n f o r d - B i n e t , a n d the A r m e d F o r c e s Q u a l i f i c a t i o n T e s t . D a t a collected o v e r the full thirty y e a r s f o r the W I S C s h o w e d a reduction of 5 . 5 p o i n t s in the g a p . O t h e r stand a r d i z a t i o n s f o r the o t h e r tests w e r e d o n e o v e r briefer p e r i o d s , but projections s h o w e d that they reached the s a m e c o n c l u s i o n on average. T h i s a m o u n t s to a reduction of one-third of a s t a n d a r d d e v i a t i o n , o r a b o u t one-third o f the d i f f e r e n c e b e t w e e n b l a c k s a n d whites, over a thirty-year period. D i c k e n s and Flynn rejected consideration of using five other IQ tests f o r w h i c h r e s t a n d a r d i z a t i o n s h a d b e e n c o m p l e t e d

because

they believed there w e r e f l a w s in the s a m p l i n g or design of the studies. R u s h t o n a n d J e n s e n ( 1 0 0 6 ) believe that f o u r o f t h o s e tests s h o u l d h a v e b e e n i n c l u d e d , all o f w h i c h s h o w e d l o w e r e s t i m a t e s o f g a i n than the tests that D i c k e n s a n d F l y n n e x a m i n e d . H o w e v e r , i f w e a n a l y z e all n i n e t e s t s f o r w h i c h t h e r e e x i s t d a t a a t t w o o r m o r e points in time, we obtain a median gain value of 4 . 5 , not very different f r o m the estimate of D i c k e n s and Flynn. If we put together the fact that the a v e r a g e IQ for the p o p u l a tion as a w h o l e is g a i n i n g at the rate of 9 p o i n t s p e r t h i r t y - y e a r generation with the fact that blacks h a v e gained a b o u t 5 points on w h i t e s o v e r the past thirty y e a r s , we will see that the b l a c k s of today have higher IQs than the w h i t e s of an earlier period in o u r history. Flynn (2008) has asked w h a t average IQ c o n t e m p o r a r y b l a c k s w o u l d score if they w e r e to t a k e the very first W e c h s l e r Adult

Intelligence

Scale

prepared

in

1947—48

(and

standard-

ized o n a w h i t e - o n l y s a m p l e ) . T h a t w a s a b o u t s i x t y y e a r s a g o , a period d u r i n g w h i c h the a v e r a g e IQ f o r the p o p u l a t i o n as a w h o l e

APPENDIX A

234

increased by 18 points. He calculates that today's blacks would outscore the whites of 1947—48 by about 4 points.

Academic

Achievement

Gains

But the black/white gap in IQ is not the only one that has been substantially reduced over time. Extremely good data show changes in the black/white gap in reading and math abilities, which are good indicators of intellectual competence and which we care about as much as IQ. Every few years, the U.S. Department of Education gives a test called the National Assessment of Educational Progress to a random sample of children aged nine, thirteen, and seventeen. We can look at the gap in reading and math for children born as early as 1 9 5 4 and as late as 1 9 9 4 . For the cohorts initially tested, reading scores for blacks were greatly lower than those for whites, with the gap ranging about 1. r to -T.2. SDs on average. For the most recent cohorts, the gap is between . 6 0 and . 8 0 SD—a very large reduction. It should be noted that progress was not uniform across the time period. In the early years there was an astonishingly high rate of reducing the gap, followed by a nontrivial increase in the gap in the middle years. Only recently has the gap started decreasing again. I know of no convincing explanations for why the rate of improvement was so high for children born in the m i d - 1 9 5 0 s to the early 1 9 7 0 s , or for why the improvement reversed itself somewhat for the children born slightly after that time, or for why the improvement has begun again. There is also good news on the black/white gap in math achievement, which measured a full i . z SDs for the first groups of children to take it. There was a dramatic improvement for children born between the m i d - 1 9 5 0 s and the late 1 9 6 0 s , a levelingo f f or slight increase in the gap for children born between the early 1 9 7 0 s and the late 1 9 8 0 s , and renewed improvement for children born since that time. Again, no clear explanation exists for any of these changes in the trend line, but the overall situation is good: a

Appendix

A

235

reduction of m o r e than a third of the g a p to the point w h e r e the math g a p is in the r a n g e of . 6 0 to . 9 0 S D . It is interesting to note that if we c o n v e r t the N a t i o n a l Assessment of E d u c a t i o n Progress g a i n s to I Q - t y p e scales, with the mean set t o 1 0 0 a n d s t a n d a r d d e v i a t i o n t o 1 5 , a n d a v e r a g e t h e g a i n s i n math and reading for nine-, thirteen-, and seventeen-year-olds, we obtain an estimate of a 5 . 4 - p o i n t reduction in the b l a c k / w h i t e g a p d u r i n g the p e r i o d f o r w h i c h D i c k e n s a n d F l y n n (2.006) f o u n d a reduction of 5 . 5 in the b l a c k / w h i t e g a p f o r I Q . In s u m , the indirect a r g u m e n t s f o r genetic d e t e r m i n a t i o n of the black/white g a p in IQ are inherently w e a k and readily refuted. T h e most direct e v i d e n c e — t h e only evidence that really c o u n t s — c o n c e r n s the E u r o p e a n heritage w i t h i n the black p o p u l a t i o n . W i t h a single e x c e p t i o n — w h i c h h a p p e n s to be the o n l y s t u d y r e p o r t e d on at any length by either Herrnstein a n d M u r r a y ( 1 9 9 4 ) or R u s h ton and J e n s e n ( 2 . 0 0 5 ) — ^ c data s h o w that m o r e E u r o p e a n genes are not a d v a n t a g e o u s for blacks. T h e last thirty y e a r s h a v e seen a r e d u c t i o n in t h e g a p in IQ by a b o u t a t h i r d a n d a r e d u c t i o n in the a c a d e m i c a c h i e v e m e n t g a p b y a b o u t the s a m e a m o u n t . T h e evidence favors a completely environmental explanation remaining difference between blacks and whites.

of the

NOTES

Chapter

1:

Varieties

of Intelligence

i

" B y intelligence the psychologist": Burt, Jones, M i l l e r , and M o o d i e ,

4 4 4

*934> P- 2-8"(Intelligence is) a very general m e n t a l " : G o t t f r e d s o n , 1 9 9 7 , p. 13. Experts in the field of intelligence: Snyderman and R o t h m a n , 1 9 8 8 . Developmental psychologist R o b e r t Sternberg has studied: Sternberg,

2.007b. 4 7 9

In addition, East Asian understanding of intelligence: Nisbett, 2 . 0 0 3 . These include " w o r k i n g m e m o r y / ' : Baddeley, 1 9 8 6 . In addition, the subtests: M. J. Kane and Engle, z o o z ; Kazui, Kitagaki, and M o r i , 2.000; Prabhakaran, R y p m a , and Gabrieli, 2 0 0 1 . 9 and another region linked: Rueda, R o t h b a r t , M c C a n d l i s s , Saccomanno, and Posner, 2.005. 9 T h e destruction of the P F C has devastating consequences: Blair, 2 0 0 6 ; Duncan, Burgess, and Emslie, 1 9 9 5 . 10 As one w o u l d expect given the lesion evidence: Blair, 2.006; Prabhakaran, R y p m a , and Gabrieli, 2 0 0 1 . 10 A d d i t i o n a l evidence: Braver and Barch, 2 0 0 2 ; C a v a n a u g h and Blanchard-Fields, 2 0 0 6 ; Raz et al., 1 9 9 7 . 1 1 T h a t fluid intelligence declines: R a z et al., 1 9 9 7 . 11 A final source of evidence: Jester et al., 2.008. 1 1 Fluid intelligence is m o r e important: Blair, 2 0 0 6 . 12 O v e r time, continued stress: Blair, 2 0 0 6 . 12 IQ tests tend to measure: Neisser, 1 9 9 6 ; Sternberg, 1 9 9 9 , 2 . 0 0 7 a . 12 Robert Sternberg measures practical intelligence: Sternberg, 1 9 9 9 ,

2006, 2.007a. 13 13

Sternberg also writes about: Sternberg, 1 9 9 9 . W h e n Sternberg measures analytic intelligence: (Sternberg, 2.006; Sternberg, W a g n e r , W i l l i a m s , and H o r v a t h , 1 9 9 5 .

1999,

237

Notes

238

14 14 14 15 15 16 17 18 20

H o w a r d Gardner argued: Gardner, 1 9 8 3 / 1 9 9 3 . These include various "personal intelligences": Lopes, G r e w a l , Kadis, Gall, and Salovey, 2.006. Emotional intelligence as measured by Salovey: Lopes, G r e w a l , Kadis, Gall, and Salovey, 2.006. Decades ago, personality psychologist Walter Mischel: Mischel, 1 9 7 4 . Mischel then waited more than a decade: Mischel, Shoda, and Peake, r988. Psychologists Angela Duckworth and Martin Seligman: Duckworth and Seligman, 2 0 0 5 . To these qualifications of the importance of IQ: Rothstein, 2004. Political scientist Charles Murray has looked at people: Murray, 2002. Murray himself has long been associated: Herrnstein and Murray, 1994.

Chapter 2j 21 21 21 23 23 24

25

25 26 26

2.:

Heritability and

Mutability

" 7 5 percent of the variance [in I Q 1 " : Jensen, 1 9 6 9 , p. 1. "Being raised in one f a m i l y " : Scarr, 1 9 9 2 , p. 3. Some still consider it: Bouchard, 2 0 0 4 , Plomin and Petrill, 1 9 9 7 . This environmentalist camp estimates heritability: Devlin, Daniels, and Roeder, 1 9 9 7 ; Otto, 2 0 0 1 ; Stoolmiller, T999. T h e researchers I call the strong hereditarians: For example, see Bouchard, 2 0 0 4 . Have a look at Table 2 . 1 : Devlin, Daniels, and Roeder, 1 9 9 7 . This figure is .74, and is essentially the one that Arthur Jensen: Jensen, 1 9 6 9 . If you are sophisticated in your knowledge about correlations but not about hereditability studies, you may wonder why the correlation of .74 is not squared in order to derive an estimate of the percent of variance accounted for by genetics. The answer is that genetic correlations are already squared. This correlation is .26: Bouchard and M c G u e , 2 0 0 3 . Another estimate of the effect of the environment comes from the difference between the correlation between parents and the children they raised (.41) and the correlation between parents and their children w h o were raised by someone else (.24). This difference is . 1 7 , which is pretty close to .20. And we can compare the correlation for siblings reared together and w h o therefore share the same environment (.46), with the correlation for siblings raised apart and w h o therefore do not share the same environment (.24). This comparison gives us an estimate of . 2 2 , which is also pretty close to .20. This is because when people: M c G u e and Bouchard, 1 9 9 8 . Billy is likely to be raised: Bronfenbrenner, 1 9 8 6 , 1 9 7 5 / 1 9 9 9 . Developmental psychologist Urie Bronfenbrenner: Bronfenbrenner, 1975/1999, 1986.

Notes 2.6

2.7 2.7

27 2.9 2.9 30

30

31

239

When environments are dissimilar: T a y l o r ( 1 9 8 0 ) also found that similarity of the environment makes a great deal of difference to the correlation of IQ between identical twins, but Bouchard ( 1 9 8 3 ) , using IQ tests different from those T a y l o r used, reached the conclusion that similarity of the environment does not make much difference to the correlation of IQ between identical twins. Devlin and his collegues: Devlin, Daniels, and Roeder, 1 9 9 7 . Once corrections are made: Devlin and his colleagues ( 1 9 9 7 ) also want to subtract 2.0 percent from the heritability estimates, owing to what they claim is the common environment in the w o m b for twins. This has proved to be controversial, however, and it remains to be seen how important the womb-similarity factor is in contributing to the similarity in intelligence between twins. Developmental psychologists Sandra Scarr: Dickens and Flynn, 2.001; Flynn, 2.007; Scarr and M c C a r t n e y , 1 9 8 3 . Psychologist Mike Stoolmiller: Stoolmiller, 1 9 9 9 . First, the socioeconomic status (SES): Maughan and Collishaw, 1 9 9 8 ; Verhulst, Althaus, and Versluis-den Bieman, 1 9 9 0 . Stoolmiller calculated that: Stoolmiller, 1 9 9 9 . Behavioral geneticist Matt M c G u e and his colleagues (2.007) studied adoptive and nonadoptive families and found evidence for only a modest range restriction on socioeconomic status (SES) and psychopathology for adoptive families as compared to nonadoptive families. In addition, they found little evidence that adoptive sibling correlations for IQ were any higher when they corrected for such range restriction than when they did not correct for range restriction. H o w e v e r , these findings have to be interpreted in light of two facts. ( 1 ) All of their families, including the nonadoptive ones, had t w o adolescent children living at home, and such families are more stable and are of a somewhat higher SES than families in general. (2.) Mothers in nonadoptive families that refused to participate had dramatically lower education levels than did the mothers of the participating nonadoptive families. T h u s , the nonadoptive families w h o participated in the study were of higher SES and were probably more stable than nonadoptive families in general. As we will see later, heritabilities for such high-SES families are substantially higher than for the population at large. Since we know that within-family variation: Stoolmiller ( 1 9 9 9 ) showed, however, that the failure to estimate correctly the degree of variation within families has led to an overestimation of the contribution of within-family variation to IQ, just as it has led to an overestimation of the contribution of heredity to IQ. Psychologist Eric Turkheimer and his colleagues: Turkheimer, Haley, Waldron, D ' O n o f r i o , and Gottesman, 2 0 0 3 . In other w o r k , Turkheimer and others found a similar modification of heritability by social class (Fischbein, 1 9 8 0 ; G r a y and T h o m p s o n , 2.004; Harden,

240

Notes

Turkheimer, and Loehlin, 2.006; R o w e , Jacobsen, and Van den Oord, 1 9 9 9 ; Scarr-Salapatek, 1 9 7 1 ) . Other investigators tailed to find this effect, however (Scarr, 1 9 8 1 ) . Even when younger and older twins are sampled by the same method—typically by mailed questionnaire—and studied longitudinally, we would expect the subjects to be progressively harder to contact and to persuade to come to the testing site as they get older. This makes it likely that the older the subject is, the more likely the subject is to be of higher socioeconomic status—hence from a group with relatively high heritability. 3 r We know from the work by Stoolmiller: Stoolmiller, 19993 1 And in fact the environment: Turkheimer (personal communication) believes that the wide range of environments in lower-SES homes may be less important in determining low heritability than the fact that many such homes do not provide an environment sufficiently favorable for genes, and the differences among them from individual to individual, to express themselves. 31 This is because . . . there is a substantial bias: Dillman, 1978. This point applies to both major types of twin studies—those that estimate heritability based on the correlation between twins reared apart and those based on Falconer's formula comparing the correlation between identical twins reared together with the correlation between fraternal twins reared together—z(MZ r - D Z r). Note that the middle-class response bias is observed in research in Europe, including Scandinavia and Holland, where some of the most frequently cited studies of adult heritability have been done (Bergstrand, Vedin, Wilhelmsson, and Wilhelmsen, 1 9 8 3 ; Dotinga, Schrijvers, Voorham, and Mackenbach, z o o s ; Jooste, Yach, Steenkamp, and Rossouw, 1990; Sonne-Holm, Sorensen, Jensen, and Schnohr, 1989; Van Loon, Tijhuis, Picavet, surtees, and Ormel, 2.003). 3z Psychologists Christiane Capron and Michel Duyme: Capron and Duyme, 1989. 33 So the study showed: Jensen ( 1 9 9 7 ) attempted to minimize the implications of this very important study by saying that the correlation between g loadings of W I S C subtests and the magnitude of the difference between biological parents and offspring arc higher than the correlation between g loadings and the magnitude of the difference between adoptive parents and offspring. In other words, subtests that measure the genuine article, namely, the most show a relation for biological parents and offspring, and the less ^-revealing subtests show a relation between adoptive parents and offspring. Many things can be said about this. (1) The difference in factor loadings on g across W I S C subtests is relatively slight, so the reanalysis does not much affect conclusions about the impact of adoption on intelligence. (2.) More importantly, there is no difference at all in average g loadings between the subtests that show a big difference between high- and low-SES adoptive parents and their offspring and those

Notes

33 34 34 35 35

241

that show little difference. Roth loadings arc .71 on average. (3) The fact that the subtests that most differentiate between biological parents and their offspring have higher g loadings than the subtests that differentiate least is almost entirely due to the fact that the Coding subtest, which has by far the lowest g loading, is one of the tests that does not differentiate much between high- and low-SES biological parents and their offspring. If Coding is left out, the g loadings for the former average .79 and for the latter average .69—not much of a difference. (4) The WISC is a heavily verbally oriented test—that is, it measures mostly crystallized intelligence, and the g loadings differ primarily to the extent that they measure verbal ability as opposed to performance or fluid skills. (5) Jensen himself (1998) said that the purest measure of fluid g is the Raven Progressive Matrices test. If we examine fluid g as defined by subtest correlations with the Raven scores, we find that the correlation for biological parents and their offspring flips direction. It is now the tests with the highest g loadings that differentiate least between high- and low-SES biological parents and their siblings. So the question as to whether the genetic effect is more reflective of differences in g than the environmental effect is entirely a matter of deciding which is the real g—fluid or crystallized. See Flynn (2000a) for a more detailed explanation of these points in the context of race differences in IQ. More important than any of these points is that the adopted children of upper-middle-class parents did far better in terms of academic achievement than did the adopted children of lower-class parents. The results of their school achievement tests were substantially better and they were far less likely to be put back a grade. And Jensen has in other contexts expressed the view that academic achievement is highly reflective of g. In any case, we care more about school achievement than about IQ. Another French study: Schiff, Duyme, Stewart, Tomkiewicz, and Feingold, 1 9 7 8 . In another extremely important natural experiment: Duyme, Dumaret, and Tomkiewicz, 1 9 9 9 . Stoolmiller showed: Stoolmiller, 1 9 9 9 . A review that examined all: van IJzendoorn, J u f f e r , and Klein Poelhuis, 200 5. This estimate w a s derived by comparing: Hereditarians may complain that the IJzendoorn estimates (van IJzendoorn, J u f f e r , and Klein Poelhuis, 2 0 0 5 ) of the effects of the adoptive-family environment are too high because they are based on young children and heredity exerts greater effects on older than on younger people—presumably because people are more able to choose their environments as they get older, and people with genes for higher IQ choose environments that will make them smarter. But IJzendoorn and colleagues (2.005) found that age of testing—twelve years or younger versus thirteen to eighteen years old—made no difference to the estimate of the effects of adoption. This is the usual finding of the relationship between age and

Notes

242

35 35

35 36

36 36 36 36 36 37 37

heritability. Heritability is constant from childhood to late adolescence ( M c G u e , Bouchard, lacono, and Lykken, 1 9 9 3 ) . As it happens, the difference: Capron and Duyme, 1989. The crucial implication of these findings: It is not just the IQ of children born to lower-SES parents that is highly modifiable by the environment. The IQ of children born to upper-middle-class parents is modifiable too. Such children have a much lower average IQ when they are raised by lower-SES parents, 1 2 points lower to be exact (Capron and Duyme, 1989). The environments of adoptive families: Stoolmiller, T999. So the relatively low correlation: As noted in the text of Chapter 2., some people claim that the very low correlations for IQ found in adulthood between people adopted into the same family establish that such between-family environmental differences as may exist are gone by adulthood, when people have the ability to choose their own environments and their genetic potential can fully exert itself. Genetically smart people, the argument goes, seek out smarter environments, and less genetically smart people drift into less smart environments, so the childhood environment is no longer very relevant to contemporary IQ. However, the only sort of correlational study that would be reliable for this conclusion is a longitudinal one, where the correlation between adoptive siblings is observed from childhood through adulthood—for the same sample of individuals. This would remove the problem of researchers typically looking at children from higher-SKS adoptive famiies when they look at adult samples than when they look at childhood samples. In fact, there appear to be only two longitudinal studies, and though they both show a reduction in the magnitude of correlations between childhood and adulthood, the samples are small and the differences between child correlations and adult correlations are not significant (Stoolmiller, 1999). Finally, since Herrnstein and M u r r a y : Herrnstein and M u r r a y , 1994. The actual value that Locurto: Locurto, 1 9 9 0 . Judith Rich Harris, the author: Harris, 1 9 9 8 . In his brilliant book: Pinker, 2.002.. "Studies have s h o w n " : Levitt and Dubner, 2 0 0 6 , p. 1 5 7 . One study looked at the IQs: Scarr and Weinberg, 1 9 7 6 . Similarly, the cross-fostering study: Capron and Duyme, 1 9 8 9 .

Chapter 39 39 39 40

3:

Getting Smarter

"even a perfect education system": M u r r a y , 2 0 0 7 a . "a person's total score": Raven, Court, and Raven, 1 9 7 5 , P- 1 • The Bell Curve: Herrnstein and M u r r a y , 1 9 9 4 . Developmental psychologists Stephen Ceci and Wendy Williams: Ceci, 1 9 9 1 ; Ceci and Williams, 1 9 9 7 .

Notes 40 40 40 40 41 41 41 41 42. 41 43 43 44 44 44 44 45 45 47 48 48 49 49 49 49 50 50 50 51 51 53 53 53 53

243

Kids are deprived of school: Ceci, 1 9 9 1 ; Jencks et al., 1972.. Much, if not most: C o o p e r , Charlton, Lindsay, and Greathouse, 1 9 9 6 ; Hayes and Grether, 1 9 8 3 . The very oldest study: F. S. Freeman, 1 9 3 4 . Another early natural experiment: Sherman and K e y , 1932.. School was delayed for Dutch children: D e G r o o t , 1 9 4 8 . The IQs of such children: R a m p h a l , 1962.. The IQs of the children: R. L. Green, H o f f m a n , Morse, Hayes, and Morgan, 1964. T w o different groups of Swedish psychologists: Harnqvist, 1 9 6 8 ; Husen, 1 9 5 1 . In fact, studies in Germany and Israel: Baltes 6c Reinert, 1 9 6 9 ; C a h a n and Cohen, 1989. Western-style education can have big effects: Ceci, 1 9 9 1 . As little as three months: Ceci, T991. In America in 1 9 0 0 : Folger and N a m , 1 9 6 7 . James R. Flynn has documented: Flynn, 1 9 8 7 , 1 9 9 4 , 1 9 9 8 . In what follows 1 stick closely: Flynn, 2.007. Scores for eighteen-year-olds: Loehlin, Lindzey, and Spuhler, 1 9 7 5 . And in any case, if completely test-naive people: Flynn, 2.007. For every child: Rutter, 2.000. The even gains across the distribution: M u r r a y , 2.007a. The graph reveals: Flynn, 2.007. Developmental psychologist Clancy Blair: Blair, G a m s o n , Thorne, and Baker, 2.005. Developmental psychologist Wendy Williams: Williams, 1 9 9 8 . Blair and his coworkers: See Blair and Razza, 2 0 0 7 . But Figure 3.2. shows: Flynn, 2.007. Researchers have shown: C. S. Green and Bavelier, 2.003. Neuroscientists have shown: Jaeggi, Perrig, Jonides, and Buschkuehl, in press. Researcher Rosario Rueda and her colleagues: Rueda, Rothbart, McCandliss, Saccomanno, and Posner, 2.005. As we might expect: Klingberg, Keonig, and Bilbe, 1 0 0 2 ; Rueda, Rothbart, McCandliss, Saccomanno, and Posner, 2.005. The A D H D researchers: Klingberg, Keonig, and Bilbe, 2.002.. Cognitive neuroscientist Adele Diamond: Diamond, Barnett, T h o m a s , and M u n r o , 2.007. Scores on t w o tests: Flynn, 2 0 0 7 . Children can learn a lot: J o h n s o n , 2.005. This seems understandable: National Flndowmenr for the Arts, 2 0 0 7 . On the other hand, we do know from other evidence: National Center for Educational Statistics, 2.008. Tables and Figures: http://nces .ed.gov/quicktables/(retrieved August 1 4 , 2.008). It is worth noting: Williams, 1 9 9 8 .

Notes

244

54 54 55 55 55 55 56 56 56

At the turn of the twentieth century: Blair, G a m s o n , Thorne, and Baker, 2.005. By 1 9 8 3 , more than: Williams, 1 9 9 8 . It does seem to have come to a halt: Schneider, 2006. In a particular region of Kenya: Daley, Whaley, Sigman, Espinosa, and Neumann, 2.003. A study on the Caribbean island of Dominica: Meisenberg, Lawless, Lambert, and N e w t o n , 2.005. This seems inevitable: J o h n s o n , 2 0 0 5 . The gains in IQ make it clear: Lynn and Vanhanen, 2002.; Rushton and Jensen, 2 0 0 5 . Finally, the evidence speaks: M u r r a y , 2 0 0 7 a . He has also said: Herrnstein and M u r r a y , 1 9 9 4 .

Chapter 57 58 58 58 58 59 59 60 60 60 6i 61 61 61 61 61 61 62 62

4:

Improving

the

Schools

U.S. students w h o score in the 95th percentile: U.S. Department of Education, 1 9 9 8 . Such additional funds may be spent: Hess, 2006. The classic case of this: Evers and Clopton, 2006. Money by itself: Evers and Clopton, 2006. Other evidence about the effect: Hanushek, 2 0 0 2 . Such studies found as much as a one-third reduction: Howell, Wolf, Peterson, and Campbell, 2 0 0 1 . When studies on the effects: Krueger, 2.001; Krueger and Z h u , Z004; L a d d , 2.002.; C. E. Rouse, 1 9 9 8 . Reasonable experiments: Bifulco and Ladd, 2.006. Unfortunately, charter schools: H o x b y and M u r a r k a , 2 0 0 7 . There is, however, some evidence: H o x b y , 2.004; H o x b y and R o c k o f f , 2.004. T h e multiple-regression analysts: Hanushek, 2.002.. On the other hand, economist Alan Krueger: Krueger and Z h u , 2.004. The children in the smaller classes: Krueger, 1 9 9 9 . The effects persisted: N y e , J a y n e Zaharias, Fulton, Achilles, and Hooper, 1 9 9 4 . Indeed so, but the fact: Hanushek, Kain, O'Brien, and Rivkin, 2.005; T . Kane, 2 0 0 7 . N o r , surprisingly, is possession: Hanushek, Kain, O'Brien, and Rivkin, 2.005. The average difference in reading: R o c k o f f , 2.004. But note that most of the difference: Hanushek, Kain, O'Brien, and Rivkin, 2 0 0 5 ; J a c o b and Lefgren, 2 0 0 5 . Defined in this w a y , 1 SD: Hanushek, Kain, O'Brien, and Rivkin, 2 0 0 5 ; T . Kane, 2 0 0 7 ; R o c k o f f , 2.004.

Notes 6z 62. 63 65

245

Economist Eric Hanushek's estimate of the impact: Hanushek, Kain, O'Brien, and Rivkin, 2 0 0 5 . A study on the effects: Pedersen, Faucher, and Eaton, 1 9 7 8 . Education researchers Bridget H a m r e and Robert Pianta: H a m r e and Pianta, 2 . 0 0 1 . H a m r e and Pianta found, in an earlier study: H a m r e and Pianta,

2001. 65 65 65 65 65 66 66 67 67 67 68 69 70 70 71 72 72 7Z 73 74 75

Principals k n o w about the quality: A r m o r , 1 9 7 6 ; M u r n a n e , 1 9 7 5 . But there is little evidence: Hanushek, Kain, O ' B r i e n , and Rivkin, z o o 5. Researchers w h o are aware: De Sander, z o o o . A c o m m o n complaint: Rosenholtz, 1 9 8 5 . Israeli researchers conducted: L.avy, z o o z . Teachers in . . . and they monitor student performance: Connell, 1 9 9 6 . T h e usual claim is that schools: M u i j s , Harris, C h a p m a n , Stoll, and Russ, Z 0 0 4 . On the other hand: M u i j s , Harris, C h a p m a n , Stoll, and Russ, 2 0 0 4 . Despite the hundreds of millions: Mosteller and Boruch, z o o z . Research is mostly anecdotal: C o o k , 2 0 0 3 . These studies generally yield: Borman, H e w e s , O v e r m a n , and B r o w n , z o o 3. Educational psychologist G e o f f r e y Borman: Borman, H e w e s , O v e r man, and B r o w n , Z 0 0 3 . A particularly well-designed: Borman et a!., z o o 7 . T h e third-party comparison studies: See also particularly rigorous tests b y T h o m a s C o o k and colleagues ( 1 9 9 9 , z o o o ) . These computer s o f t w a r e systems: Kulik, 2 0 0 3 . Education researcher: Robert Slavin (Slavin, 1 9 9 5 ) . Slavin reported studies: Slavin, 1 9 9 5 . T h e r e are a variety of ways: Slavin, 1 9 9 5 . In an extremely w e l c o m e development: U.S. Department of Education, zoo8. Herrnstein and his c o w o r k e r s : Herrnstein, N i c k e r s o n , Sanchez, and Swets, 1 9 8 6 . In fact, M a r k Lepper and his colleagues found: Lepper, Drake, and O'Donnell-Johnson, 1 9 9 7 ; Lepper, W o l v e r t o n , M u m m e , and Gurtner, T 9 9 3 ; Lepper and W o l v e r t o n , Z O O T .

Chapter 78 78 80

5:

Social

Class

and

Cognitive

Culture

" t h e class structure of m o d e r n " : H. J. Eysenck, 1 9 7 3 , p. 1 9 . T h e average I Q : Flynn, z o o o b . Although the available evidence: Pollitt, G o r m a n , Engle, M a r t o r e l l , and Rivera, 1 9 9 3 .

Notes

246

50 80 80 80 80 80

Ir is not clear that nutrition differences: Rothstein, 2 0 0 4 . Even if hunger is rare: General Accounting O f f i c e , 1999. A n d there is evidence: Schocnthaler, A m o s , Fysenck, Peritz, and Yud kin, 1 9 9 1 . T h e effects of lead: Baghurst, 1 9 9 2 . . Children w h o s e mothers drank: Centers f o r Disease C o n t r o l and Prevention, 2 0 0 7 . Lower-SES w o m e n : Streissguth, Barr, Sampson, Darby, and Martin,

1989. 81 81 51

8 1

81 82 82 82 S3 S3 53

84 54 85

L o w birth weight: H a c k , Klein, and T a y l o r , 1 9 9 5 . Lower-SES mothers: Anderson, Johnstone, and Rem ley, 1999; U.S. Department of Health and H u m a n Services, 2 0 0 6 . For children with the most c o m m o n : Anderson, Johnstone, and Remley, 1 9 9 9 ; Caspi, 2 0 0 7 ; Kramer, 2 0 0 8 ; Luca, M o r l e y , C o l e , Lister, and Leeson-Payne, 1 9 9 2 . O n e study finds: Der, Batty, and Deary, 2 0 0 6 . On the other hand, in one study ( K r a m e r , 2 0 0 8 ) , mothers were encouraged to breast-feed exclusively, and this experimental study g o t the same results as the correlational studies. Lower-SES people: M i l l s and Bhandari, 2 0 0 3 . O n e such harmful circumstance: Rothstein, 2 0 0 4 . Lower-SES children are more likely: Rothstein, 2 0 0 4 . C o m p a r e d with higher-SES parents: D o d g e , Pettit, and Bates, 1 9 9 4 . Developmental psychologist V o n n i e M c L o y d : V . M c L o y d , 1 9 9 8 . Farly emotional trauma: Blair, 2 0 0 6 . Income inequality in the United States: Economic and literacy statistics in this paragraph and the next c o m e f r o m a recent book on the American labor market by Richard Freeman ( 2 0 0 7 ) . In contrast, the after-tax: Rothstein, 2 0 0 4 . Reflecting the differences: Organisation for Economic Co-operation and D e v e l o p m e n t , 2 0 0 1 . T h e difference in reading and math skills: M i c k l e w r i g h t and Schnepf,

2004. 85 85 86 86 87 87 87 89 90

In fact, the achievement gap: Ceci, 2 0 0 7 . W h i l e their children: Lareau, 2 0 0 3 Psychologists Betty Hart and T o d d Risley: Hart and Risley, 1 9 9 5 . Degree of encouragement: Brooks-Gunn &c M a r k m a n , 2 0 0 5 . M u c h o f what w e k n o w : Heath, 1 9 8 2 , 198^. Heath's study was conducted . . . but more recent studies: Lareau, 2 0 0 3 ; Mikulecky, 1 9 9 6 . In what f o l l o w s . . . recent w o r k of Annette Lareau: Laueau, 2 0 0 3 . A Philadelphia study: N e u m a n and C e l a n o , 2 0 0 1 . T h e I Q s and skills of middle-income children: C o o p e r , N y e , Charlton, Lindsay, and Greathouse, 1 9 9 6 .

Notes 90 92.

247

O n e study found: Burkham, Ready, Lee, and L o G e r f o , 2 0 0 4 . In fact, there is some evidence: C. Rouse, Brooks-Gunn, and M c L a n a -

han, 2 0 0 5 .

Chapter 6: IQ in Black and White 93 93 93 93 95 95 95 95 96 96 96 96 96 96

97 97 97 97 97 97

" T h e taboo against discussing race": Soweli, 1 9 9 4 , p. 1 6 8 . "[Black] kids seem t o " : O g b u , 2 . 0 0 3 , P- 7**A millennium earlier southern Europeans: Soweli, 1 9 9 4 , p. 1 5 6 . though Julius Caesar: Churchill, 1 9 7 4 , p. 2.. In this chapter and in Appendix B: Rushton and Jensen, 2.005. There is plenty of evidence: Steele, 1 9 9 7 ; Steele and Aronson, 1 9 9 5 . When the test is presented: Steele, Spencer, and Aronson, 1 0 0 2 . . At least as late as 1 9 8 0 : Jensen, 1 9 8 0 . T h e correlation between brain size and IQ may be: Schoenemann, Budinger, Sarich, and W a n g , 1 9 9 9 . And according to a number of studies: These are reviewed in Rushton and Jensen, (2.005). In fact, however, there is no such correlation: Shoenemann, Budinger, Sarich, and W a n g , 1 9 9 9 . M o r e o v e r , the brain-size difference: Ankney, 1992.. And a group of people in a community in Ecuador: Guevara-Aguire et al., 1991; Kranzler, Rosenbloom, Martinez, and Guevara-Aguire, 1 9 9 8 . T h e direction of recent evolution: Beals, Smith, and D o d d , 1 9 8 4 ; Brown, 1992.; Brown and M a e d a , 2.004; Henneberg, 1 9 8 8 ; Henneberg and Steyn, 1 9 9 3 , r 9 9 5 ; Schwidetsky, 1 9 7 7 . About 2.0 percent of the genes: Parra et al., 1 9 9 8 ; Parra, Kittles, and Shriver, 2 0 0 4 . It turns out that light skin color: Shuey, 1 9 6 6 . Tested in later childhood: Eyferth, 1 9 6 1 . But when a group of investigators: Witty and Jenkins, 1 9 3 4 . T h e blood group assays: Scarr, Pakstis, Katz, and Barker, 1 9 7 7 . Similarly, the blood groups: Loehlin, Vandenberg, and Osborne, r 973-

98 98 98

T h e hereditarians cite a study: Scarr and Weinberg, 1 9 8 3 ; Weinberg, Scarr, and W a l d m a n , 1992.. A superior adoption study: M o o r e , 1 9 8 6 . Psychologists Joseph Fagan and Cynthia Holland: Fagan and Holland,

2002., 2.007. 99 99 100 101

Indeed, black IQ n o w : Dickens and Flynn, 2.006. In fact, we k n o w : Dickens and Flynn, 2 0 0 6 . T h e shrinkage of the gap: Dickens and Flynn, 2 0 0 6 . Black family income: Rothstein, 2.004.

Notes

248

101 101

T h e unwed mother rate: C a m a r o t a , 2 . 0 0 7 . A f f i r m a t i v e action has likely played: Thernstrom and Thernstrom,

103 103

1997. Employers believe that young: M o s s and T i l l y , 2 . 0 0 1 . W h e n black and white job applicants: Dariry and M a s o n , 1 9 9 8 ; Darley and Berscheid, 1 9 6 7 . T h e white applicants: Pager, 2 0 0 3 . Already i n 1 9 6 5 : M o y n i h a n , 1 9 6 5 . In 2 0 0 5 , f o r blacks age t w e n t y - f i v e to twenty-nine years old, the ratio of females to males: U.S. Census Bureau, 2 0 0 6 . Since w e k n o w that more: Flynn, 1 9 8 0 . As a consequence at least: U. S. O f f i c e of Personnel Management,

103 103 103 104 104 104

Race may be: M y r d a h l , 1 9 4 4 . African anthropologist John O g b u : O g b u , 1 9 7 8 , 1 9 9 4 . T h e I Q differences between: Sowell, 1 9 9 4 . These groups include whites: Ceci, 1991. O g b u focuses on: O g b u , 1 9 9 1 a . Unlike lower-caste minorities: Sampson, xMorenoff, and Raudenbush,

102 102 102 102 102

2006.

2005. 104 104 104 105 105 105 106 106 106 108 108 108 108 108 ro9

O g b u holds that: O g b u , 1 9 7 8 . In the case of American blacks: O g b u , 2 . 0 0 3 . O g b u has written: For example, see O g b u , 1991b. I n what f o l l o w s I d r a w : Sowell, 1 9 7 8 , 1 9 8 1 , 1 9 9 4 ; Flynn, 1 9 9 1 a . I n eighteenth-century Virginia: Sobel, 1 9 8 7 . T h o u g h most free blacks: Sowell, 1 9 7 8 . Eighty-five percent o f free: Sowell, 1 9 7 8 . I n C h i c a g o i n 1 9 1 0 : Sowell, 1 9 7 8 . T o give a n idea: Sowell, 1 9 7 8 . T h e Irish, w h o w e r e white: Ignatiev, 1 9 9 5 . A s o f the mid-twentieth century: M a c n a m a r a , 1 9 6 6 . English psychologist H . J . Eysenck: Eysenck, 1971. T h e gene p o o l . . . and literary proficiency: Organisation for Economic C o - o p e r a t i o n and D e v e l o p m e n t , 2.000. Post—secondary school enrollment: Organisation f o r Economic C o operation and D e v e l o p m e n t , 2 0 0 0 . T h e proportion of blacks: A t t e w e l l , D o m i n a , L.avin, and Levey,

2004. 1 10 1 10 1 10 t 10

In 1 9 7 0 , second-generation West Indians: Sowell, 1 9 7 8 . T h e y took whatever jobs: Sowell, 1 9 7 8 ; Waters, 1 9 9 9 A n d West Indian culture: Sowell, 1 9 7 8 . Sowell recently argued: Sowell, 2 0 0 5 . Sowell is w o r t h quoting at length on this point. From page 6 of his b o o k Black Rednecks and White Liberals: " T h e cultural values and social patterns prevalent a m o n g Southern whites included an aversion to w o r k , proneness to violence,

Notes

111 l 12 1 13 113 114 1 1 5 1 15 1 1 5 1 1 5

249

neglect of education, sexual promiscuity, improvidence, drunkenness, lack of entrepreneurship, reckless searches f o r excitement, lively music and dance, and a style of religious oratory marked by strident rhetoric, unbridled emotions, and flamboyant i m a g e r y / ' From pages 1—2.: " T h a t culture long a g o died out where it originated in Britain, while surviving in the American South. T h e n it largely died out a m o n g both white and black Southerners, while still surviving today in the poorest and worst of urban black g h e t t o s . " 1 pointed out: Hart and Risley, 1 9 9 5 . Recall from the last chapter: H e a t h , 1982, 1 9 8 3 . This probably pays o f f : Loehlin, Lindzey, and Spuhler, 1 9 7 5 . In fact, those abilities: Heath, 1 9 8 2 . . In the late 1 9 8 0 s : Heath, 1 9 9 0 . Meredith Phillips, Jeanne Brooks-Gunn: Phillips, Brooks-Gunn, Duncan, K l e b a n o v , and Crane, 1 9 9 8 . O n e came f r o m a study: Chase-Lansdale et al., 1 99 1. T h e second data set came: Brooks-Gunn et al., 1 9 9 4 . Things studied include: M. Phillips, Brooks-Gunn, Duncan, K l e b a n o v ,

and Crane, 1 9 9 8 , pp. 1 2 6 - 1 27 1 16 Hart and Risley, in their study: Hart and Risley, 1 9 9 5 . 1 16 T h e three-year-old black child: T o u g h , 2.007. 116 Recall the study: M o o r e , 1 9 8 6 . 1 18 These subcultures encourage: Patterson, 2 0 0 6 .

Chapter 7: Mind the Gap 1 19 " C o m p e n s a t o r y education'": Jensen, 1 9 6 9 , p. 1. 1 19 " T h e r e is no e v i d e n c e " : Jencks et al., 1 9 7 2 . , p. 8. 1 19 " T h e r e is no r e a s o n " : M u r r a y , 2 0 0 7 a . 121 It results in mortality rates: L u d w i g and M i l l e r , 2 . 0 0 5 . 1 2.1 In earlier days. H e a d Start: M c K e y , Condelli, Ganson, M c C o n k e y , and Plantz, 1 9 8 5 . 121 and more recent studies: Grissmer, Flanagan, and W i l l i a m s o n , 1 9 9 8 ; L u d w i g and M i l l e r , 2 . 0 0 5 . 1 2.1 Recent reports show l o w e r effect sizes: U.S. Department of Health and Human Services, 2 0 0 5 . rzi W h a t little there is: L u d w i g and M i l l e r , 2 0 0 5 . O n e study found that the benefits of greater high school completion and college attendance are limited to whites: Garces, T h o m a s , &t Currie, 2.002.. 1 2.2. T h e cost of Head Start: For a pessimistic review of the literature on Head Start, see Besharov, 2 0 0 5 . For a more optimistic review of Head Start, see L u d w i g and Phillips, 2 0 0 7 . H o w e v e r , the latter relies on study designs that I consider inferior. A n o t h e r optimistic study is by Deming, 2 0 0 8 .

250

121 122 123

Notes

Early H e a d Start: L o v e , 2005. A review of about: Grissmer, Flanagan, and W i l l i a m s o n , 1998. T h e Perry Preschool Program: Schweinhart e t al., 2 0 0 5 ; Schweinhart and W e i k a r t , 1 9 8 0 , 1 9 9 3 . 124 These advantages include: Barnett, 1992. 1 24 The fact that gains: Knudsen, Heckman, Cameron, and Shonkoff, 2006. 124 A n intervention even m o r e ambitious: Garber, 1 9 8 8 . 1 2 6 A yet m o r e intensive intervention: Campbell et al., 2 0 0 1 ; Campbell and R a m e y , 1 9 9 5 ; C. T. R a m e y et al., 2 0 0 0 ; S. L.. Ramey and Rarney, 1999. 1 2 9 O n e is important because: Herrnstein ad M u r r a y , 1 9 9 4 . T 29 Project Care, using methods: Wasik, Ramey, Bryant, and Sparling, 1 9 9 0 . 129 A n o t h e r replication o f Abecedarian: Gross, Spiker, and Haynes, 1 9 9 7 ; Hill, Brooks-Gunn, and W a l d f o g e l , 2 0 0 3 ; T h e Infant Health and Development Program, 1 9 9 0 . 1 30 A particularly important fact: G o r m l e y , G a y e r , Phillips, and D a w s o n , 2 0 0 5 ; L o v e e t al., 2 0 0 5 . 1 3 0 and benefit p o o r children: H a m r e and Pianta, 2 0 0 5 . 1 3 0 Some reasonably ambitious parenting interventions: Brooks-Gunn and M a r k m a n , 2 0 0 5 ; Juffer, H o k s b e r g e n , Riksen-Walraven, and K o h n s t a m m , 1 9 9 7 ; van Z e i g l , M e s m a n , van IJzendoorn, BakersmanKranenburg, and Juffer, 2 0 0 6 ; W a t a n a b e , 1 9 9 8 . 1 3 0 T h i s w a s conducted: Landry, Smith, and Swank, 2 0 0 6 ; Landry, Smith, Swank, and Guttentag, 2 0 0 7 . 132 T h e H e r i t a g e Foundation: Carter, 2 0 0 0 . 132 Richard Rothstein: Rothstein, 2 0 0 4 . 1 3 2 T h e F'ducation Trust: Jerald, 2 0 0 1 . 133 Rothstein gives a n even: Reeves, 2 0 0 0 . 133 T h e Neiv York Times announced: Finder, 2 0 0 5 . 133 and yet again: Bazelon, 2 0 0 8 . 1 3 4 T h e black/white gap w a s actually: Y o u can see the comparison of W a k e C o u n t y and statewide scores at the state's education W e b site: http://www.ncreportcards.org/src/distDetails.jsp?Page=2&:pSchCode= 304&:pLEACode=9 2o&:pYear=2oo4-2oo5&:pDataType=T 134 By the n e w standards: Data f o r 2 0 0 5 / 0 6 math scores are more interpretable because the cutoffs for proficiency scores are much l o w e r than f o r 2 0 0 4 / 0 5 . As in many states, what is labeled " p r o f i c i e n t " in N o r t h Carolina bounces around f r o m year to year depending more on politics than on actual student achievement. T h e 2 0 0 5 / 0 6 data, when the required level f o r proficiency went up again, tell the same story. T h e W a k e County black/white g a p w a s no smaller than it was for the state as a w h o l e . T h e Times writer w o u l d have done well to get his figures at the source rather than depending on data and interpretations o f f e r e d by educators relying on the W a k e C o u n t y district reports. 134 There is g o o d evidence: Murnane, Willett, Bub, and McCartney, 2 0 0 6 .

Notes 134 13 5 135 135 135 135

251

Hxpcrience in teaching counts, though: Sanders and Horn, 1 9 9 6 . Again, there is the possibility: Sanders and Horn, 1 9 9 6 And we know that: Hamre and Pianta, 2.005. We also know that: Grissmer, Flanagan, and Williamson, 1 9 9 8 . The math training program: H. Phillips and Ebrahimi, 1 9 9 3 . One study of Project S E E D ' s effectiveness: Webster and C h a d b o u r n , 1992.. 1 3 6 Reading Recovery is a tutoring program: Slavin, 1 9 9 5 . 1 3 6 The Ohio Stare group conducted randomized studies: Slavin, 1 0 0 5 . 1 3 6 One independent study evaluating: Slavin, 2 0 0 5 . 1 36 There is at least one extremely: All of the information about KIPP comes from a report by the Stanford Research Institute: David et al., 2.006. 1 3 7 KIPP maintains that " w h i l e the average fifth-grader": KIPP Web site, quoted in M a t h e w s 2006. 1 3 7 However, SRI International conducted: David et al., 2.006. 1 3 8 Principals believe: Quotations are from David et al., 2006. 14 1 The next step will be: T w o other systems are similar to KIPP in design. One is called Achievement First and operates primarily in N e w Haven, Connecticut, and the other is called North Star and operates in N e w ark, New Jersey. These programs claim good results with children resembling the KIPP students. But they have not been well evaluated to my knowledge. 142. There's good news: Jessness, 2.002.. 1 4 3 They showed, not surprisingly: Blackwell, Trzesniewski, and D w e c k , 2.007; Henderson 6c D w e c k , 1 9 9 0 . 1 4 3 Dweck and her colleagues: Blackwell, Trzesniewski, and D w e c k , 2.007. 1 4 3 Dweck reported that some: Personal communication, J a n u a r y 2.007 1 4 3 Joshua Aronson and his colleagues: Aronson, Fried, and G o o d , 2.002. 1 4 3 One study was conducted: G o o d , Aronson, and Inzlicht, 2 0 0 3 . 1 4 4 Daphna Oyserman and her coworkers: Oyserman, Bybee, and T e r r y , 2.006. 145 Social psychologists Gregory Walton and G e o f f r e y Cohen: Walton and Cohen, 2.007. See also another effective, brief intervention by G. L. Cohen, Garcia, Apfel, and Master (2006). 146 Herrnstein and Murray: Herrnstein and M u r r a y , 1 9 9 4 . 1 4 6 Blacks start out high school: Myerson, R a n k , Raines, and Schnitzler, 1998. 1 4 6 Psychologist Joel Myerson and his coworkers: Myerson, R a n k , Raines, and Schnitzler, 1 9 9 8 . 1 4 7 A third possible answer: Aronson and Steele, 2.005; Steele and Aronson, 1 995* 1 4 7 One study that followed: Osborne, 1 9 9 7 . 148 Another long-term study: Massey and Fischer, 2 0 0 5 . i 50 The Nobel Prize—winning economist James Heckman: Heckman, 2.006.

Notes

252

1 5 0 T h e initial cost: Besharov, 2 0 0 7 . 1 50 The same is true: Masse and Barnett, 2.002.. 1 50 Even when benefits: Dickens and Baschnagel, 2008. 1 5 1 As a yardstick for measuring: Institute on Taxation and Economic Policy, 2 0 0 7 . 151

The cost per pupil: Institute of Education Sciences, 2006.

Chapter 153 153 153 153 154 154 1 54

154 1 54 154 154 154 1 54

1 54

8; Advantage Asia?

In 1 9 6 6 , Chinese Americans: Flynn, 1 9 9 1 a , 2007. In 1 9 8 0 — w h e n they were: Flynn, 2 0 0 7 . In the late 1 9 8 0 s : C a p l a n , Whitmore, and C h o y , 1 9 8 9 . In 1 9 9 9 , U.S. eighth-graders: National Center for Education Statistics, 2000. Although Asian Americans constitute: Quindlen, 2008a. Asian and Asian American students: Anonymous, 2 0 0 7 ; Anonymous, 2008a. So European Americans: Throughout the discussion in this chapter, my generalizations are meant to apply only to Flast Asians and not to South Asians. I believe that some of the generalizations apply to South Asians as well, but the evidence—and there is a lot of it—concerns East Asians primarily. When I refer to " A s i a n s " or "Easterners" in what follows I a l w a y s mean Flast Asians such as Chinese, Japanese, Koreans, and citizens of T a i w a n , Singapore, and Hong Kong, all of w h o m have cultures that are Confucian historically and at base today. Herrnstein and M u r r a y : Herrnstein and M u r r a y , 1 9 9 4 . Rushton and Jensen: Rushton and Jensen, 2 0 0 5 . Philip Vernon: Vernon, 1982.. Richard Lynn: Lynn, 1 9 8 7 . but Flynn: Flynn, 1 9 9 1 a . Most showed that East Asians: All comparisons that I am aware of between Asians or Asian Americans on the one hand and European Americans on the other show that Asian and Asian American scores on performance IQ tests, and especially visuospatial tests such as block design, are high relative to scores on verbal IQ tests, though the difference is usually slight. Herrnstein and Murray attribute this relatively greater performance ability of Asians to genetic differences, which certainly cannot be ruled out. On the other hand, as you will see later in this chapter, there are cultural differences that encourage attention to broad aspects of the visuospatial world more for Asians and Asian Americans. In addition, East Asian colleagues have told me that spatial problems resembling those found on IQ tests are taught in school to a much greater degree than is true in the West. Harold Stevenson and his coworkers: Stevenson et al., 1990.

Notes 155 155 156 156 157 157 158 158 158 158

253

162. 164 r64 164 164 166 166 166 167

Kvcn more astonishing: Stevenson and Stigler, 1 9 9 2 . . T h e Coleman report on educational quality: Flynn, 1991a. Despite their slightly inferior: Flynn, 1 9 9 1 a . By the age of thirty-two: Flynn, 1991a. Recently, Flynn studied: Flynn, 2 0 0 7 . A n d indeed they did: Flynn, 2 . 0 0 7 . Asian and Asian American achievement: Nakanishi, 1 9 8 2 . . T h e high-school-age children: Caplan, W h i t m o r e , and C h o y , 1 9 8 9 . Black eighth-grade children: O y s e r m a n , By bee, and T e r r y , 2.006. Asians today still believe: Chen and Stevenson, 1 9 9 5 ; C h o i and Markus, 1 9 9 8 ; C h o i , Nisbett, and N o r e n z a y a n , 1 9 9 9 ; Fieine et al., 2 . 0 0 1 ; H o l l o w a y , 1 9 8 8 ; Stevenson e t al., 1 9 9 0 . A team of Canadian psychologists: Heine et al., 2 0 0 1 . But a still more important reason: Nisbett, 2 . 0 0 3 . These Fast-West differences: M y account o f the social differences between Easterners and Westerners, as well as some of the resulting cognitive differences, is an abbreviation of points made in my b o o k The Geography of Thought: How Asians and Westerners Think Differently . . . and Why. T h a t b o o k reports on historical and c o n t e m p o r a r y social and cognitive trends that differentiate Europeans and European Americans f r o m East Asians and Americans of Flast Asian extraction. I refer you to that book for documentation of most of the assertions in this chapter about historical differences between Asians and Westerners and for detailed descriptions of a large number of studies on the perceptual and cognitive habits of c o n t e m p o r a r y people. T a k a h i k o Masuda and I: Masuda and Nisbett, 2 0 0 1 . In another study, Masuda: M a s u d a , et al., 2 0 0 8 . Chinese spend m o r e time: Chua, Boland, and Nisbett, 2 0 0 5 . Social psychologists have uncovered: Ross, 1 9 7 7 . Koreans in this situation: Choi and Nisbett, 1 9 9 8 . W h e n w e presented people: Ji, Z h a n g , and Nisbett, 2 0 0 4 . W e also presented: N o r e n z a y a n , Smith, K i m , and Nisbett, 2 0 0 2 . My c o w o r k e r s and I: Peng, 1 9 9 7 . For example, when Chinese: Gutchess, Welsh, Boduroglu, and Park,

167

Consistent with this fact: Fledden, Ketay, A r o n , M a r k u s , and Gabrieli,

167 167 167 168

First, in several of the studies: Nisbett, 2 0 0 3 . W e found residents o f Fiong K o n g : Ji, Z h a n g , and Nisbett, 2 0 0 4 . A n d when Flong K o n g residents: H o n g , Chiu, and K u n g , 1 9 9 7 . T h e Japanese have spent: Organisation f o r Economic C o - o p e r a t i o n and D e v e l o p m e n t , 2 0 0 7 . " I w o r k e d a t the Carnegie Institution": French, 2 0 0 1 . Second, the C o n f u c i a n tradition: Munro, 1969; Nakamura,

158 159 160

2006. 2008.

169 169

1 964/1 9 8 5 .

Notes

254

170 170

In fact, the children: Watanabe, 1 9 9 8 . Nils Bohr credited: Bohr, 1 9 5 8 .

Chapter 9: 171 171 171 172 172 172 172 172 172 172 173

173

People of the

Book

" [ T h e J e w s J are peculiarly": Jewish Virtual Library, 2.007. " T h e United States t o d a y " : Sugar, 2006. American J e w s have received: Anonymous, 2.008b; J I N F O . O R G , 2.008. Approximately the same overrepresentation: Anonymous, 2008b; J I N F O . O R G , 2008. And 26 to 34 percent: A n o n y m o u s , 2 0 0 3 ; Anonymous, 2008b. In the United States, J e w s : Freedman, 2000. an approximately equal: Anonymous, 2 0 0 3 . and about 30 percent: A n o n y m o u s , 2 0 0 3 . According to the 1 9 3 1 census: Statistics in this paragraph come from M a r c u s (1 983). Most reports place: Backman, 1 9 7 2 ; Lesser, Fifer, and C l a r k , 1 9 6 5 ; Levinson, 1 9 5 9 ; Majoribanks, 1 9 7 2 . If we assume an average IQ of 1 1 0 : Incidentally, despite this difference in the probability of having an IQ of 1 4 0 , the probability of a random J e w having an IQ that is higher than that of the average white nonJ e w is only . 7 5 , assuming an average Jewish IQ of 1 1 0 ; assuming an average Jewish IQ of 1 1 5, the probability is .84. Such is the surprising outcome predicted by the elevation of the normal distribution curve at various degrees of distance from the mean. It is important to note: Burg and Belmont, 1 9 9 0 ; Ortar, 1 9 6 7 ; Patai, 1 9 7 7 . Before leaving the topic of Jewish IQ, I should note that there is an anomaly concerning Jewish intelligence. The major random samples of Americans having large numbers of Jewish participants show that whereas verbal and mathematical IQ run 10 to 15 points above the non-Jewish average, scores on tests requiring spatial-relations ability (ability to mentally manipulate objects in two- and three-dimensional space) are about 10 points below the non-Jewish average (Flynn, 1 9 9 1 a ) . This is an absolutely enormous discrepancy and I know of no ethnic group that comes close to having this 20 to 25-point difference among J e w s . I do not for a minute doubt that the discrepancy is real. I k n o w half a dozen J e w s w h o are at the top of their fields w h o are as likely to turn in the wrong direction as in the right direction when leaving a restaurant. The single ethnic difference that I believe is likely to have a genetic basis is the relative Jewish incapacity for spatial reasoning. I have no theory about why this should be the case, but I note that it casts an interesting light on the J e w s 1 wandering in the desert for forty years!

Notes 173 174 174 175 176 178 178

179 180

255

This is true even: Gross, 1 9 7 8 . C o m p l e t e elimination f r o m reproduction: Loehlin, V a n d e n b e r g , and Osborne, 1 9 7 5 . T h e geneticist Cyril Darlington: Darlington, 1 9 6 9 . Political scientist Charles M u r r a y : M u r r a y , 2 0 0 7 b . Anthropologists G r e g o r y Cochran, Jason H a r d y : Cochran, H a r d y , and Harpending, 2.005. Fifteen percent of all scientists: Sarton, 1 9 7 5 . Even within Europe: In his b o o k Human Accomplishment Charles M u r r a y ( Z 0 0 3 ) documented the swings of achievement in different regions. " I t i s counted a title": Z w e i g , 1 9 4 3 / 1 9 8 7 . Psychologist Seymour Sarason: Sarason, 1 9 7 3 .

Chapter 10; Raising Your Child^s Intelligence . . . and Your Oivn 183 184 184 184 184 184 184 185 185 185 185

185 186

T h e r e is no evidence: Bruer, 1 9 9 9 . T h e research suggesting: Bruer, 1 9 9 9 . W e find the same kind: D u y m e , 1 9 8 1 . W o m e n w h o exercise: C l a p p , K i m , Burciu, and L o p e z , 2 0 0 0 . T h e babies born t o exercising: M c D a n i e l , 2 0 0 5 . Exercising large muscle groups: G . D . C o h e n , 2 0 0 5 . Experiments show that elderly: C o l c o m b e and Kramer, 2 0 0 3 . Y o u can even start: A a m o d t and W a n g , 2 0 0 7 . Breast-feeding beyond nine months: M o r t e n s e n , Michaelsen, Sanders, and Reinisch, 2002.. It seems to be particularly important: Anderson, Johnstone, and R e m ley, 1999T h e activities that increase: Klingberg, K o e n i g , and Bilbe, zoo2.; Mortensen, Michaelsen, Sanders, and Reinish, O l e s o n , Westerberg, and Klingberg, 2 0 0 3 . Neuroscientist R o s a r i o Rueda: Rueda, R o t h b a r t , M c C a n d l i s s , Saccomanno, and Posner, 2 0 0 5 . Child neurologist T o r k e l Klingberg: Klingberg, K o e n i g , and Bilbe,

2002. 186

186 186

Similar exercises improved: If your child has attention deficit hyperactivity disorder, you may w a n t to contact a specialist skilled in administering training like that used by Klingberg and his colleagues ( 2 0 0 2 ) . T h e list is available at http://www.cogmed.com/cogmed/articles/en/78 .aspx Finally, meditation exercises: T a n g et al., 2 0 0 7 . Personality psychologist W a l t e r Mischel: A y d u k , D o w n e y , Testa, Y e n , and Shoda, 1 9 9 9 ; Mischel, Shoda, and R o d r i g u e z , 1 9 8 9 .

Notes

256

187 187 187 188 189 189 190 190

Recall that psychologists: Duckworth and Seligman, 1 0 0 5 . We do know that if: Mischel, Shoda, and Rodriguez, 1989. Also, Mischel and his coworkers had: Mischel, Shoda, and Rodriguez, 1989. And Asians work harder: Heine et al., 2.001. When children are praised: Mueller and D w e c k , 1 9 9 8 . In a clever experiment: Mueller and Dweck, 1 9 9 8 . With developmental psychologists Mark Lepper and David Green: Lepper, Greene, and Nisbett, 1 9 7 3 . If a child has low: Calder and Staw, 1 9 7 5 ; Lovcland and Olley, 1 9 7 9 ; V. C. M c L o y d , J 979.

Epilogue: What We Noiv Knoiv about Intelligence and Academic Achievement 195 195 195

First of all: Gottfredson, 1 9 9 7 . Heuristics for reasoning: Nisbett, 1992.. Planning and choosing: l.arrick, M o r g a n , and Nisbett, 1 990; Nisbett, Fong, Lehman, and Cheng, 1 9 8 7 .

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CREDITS

Figure 1.1 Figure 1.2. Box 1.1 T a b l e 2.1 Figure 3.1 Figure 3.2 Figure 7.1

Figure 8.1

Reprinted with permission f r o m Flynn, 2.007, P- 1 6. C o p y r i g h t James R. Flynn. Reprinted with permission f r o m Cattell, 1 9 8 7 , p. 2 0 6 . C o p y right EJsevier Science Publishers. Reprinted with permission f r o m Flynn, 2007, p. 5. C o p y r i g h t James R. Flynn. Reprinted with permission f r o m Devlin, Daniels, and R o e d e r , 1997, P- 469* C o p y r i g h t N a t u r e Publishing G r o u p . Reprinted with permission f r o m Flynn, 2007, p. 8. C o p y r i g h t James R. Flynn. Reprinted with permission f r o m Eicholz, R . , 1991, p. 56. C o p y right Pearson Education. Reprinted with permission f r o m Knudsen, H e c k m a n , C a m e r o n , and S h o n k o f f , 2006, p. 10156. C o p y r i g h t N a t i o n a l A c a d e m y of Sciences of the United States of A m e r i c a . Reprinted with permission f r o m Masuda and Nisbett, 2001, p. 924. C o p y r i g h t American Psychological Association.

283

INDEX

Page numbers in italics refer to boxes and figures. Page numbers beginning with 2 3 7 refer to notes. Abecedarian P r o g r a m , 126—29, 128 f 150, 152 abstract reasoning, 4, 7, 8, 9 academic achievement: as "acting w h i t e , " 104, 147 in adoption studies, 35, 120, 183, 241 of Ashkenazi Jews, 171—72, 1 7 9 - 8 1 , 198 of Asian Americans, 155—57, 198 of Asians, 155, 1 5 8 - 5 9 , 198 of black females, 1 0 2 - 3 of black males, 1 0 2 - 3 , 1 0 4 - 5 , 118, 147-48 black/white gap in, see black/ white g a p , in academic achievement charter schools and, 60, 72, 132, 137, 139-40, 149, 195 class size and, 61, 83, 135, 206 correlation of occupational achievement with, 17, 157 creative intelligence and, 13—14, 17 delay of gratification and, 15, 16, 187 early childhood education and, 122-28, 128, 130, 148 Fast/West gap in, see Flast/West gap, in academic achievement effect sizes in, 203

environmental impact on, 2, 3 of free persons of c o l o r , 1 06 hard w o r k and, 143, 158, 188-90 Mead Start and, 1 2 1 - 2 2 as heritable, 1 Hispanic/white gap in, 120, 133-34, 1 4 1 - 4 2 impact of teachers o n , 61—66, 73, 1 3 4 - 3 5 , 191, 196 income inequality and, 85, 152 intelligence and, 5, 1 3 - 1 4 , 17, 55, 156, 182, 187, 1 9 3 - 9 9 interventions and, 1 - 2 , 70, 73, 131-36, 144, 146, 148-49, 197-98 IQ gains and, 55 IQ tests as predictors o f , 5, 12, 16, 17, 4 5 - 4 6 , 51 of minorities, 2, 3, 13—14, 104, 131, 145, 146, 197 motivation and, 16, 104-5, 147, 155 parenting practices and, 79, 88, 90, 183 parents' IQ and, 18 practical intelligence and, 13, 17 rewards f o r , 137, 138, 190 self-control and, 15, 16, 1 8 6 - 8 8 self-esteem and, 147—48 SES and, 2, 3, 18, 3 3 - 3 4 , 63, 85, 9 0 - 9 1 , 131, 134, 157 2X5

286

academic achievement (continued) skin c o l o r a n d , 2 2 6 strategies f o r increasing o f , 182— 92, 198-99 student t u r n o v e r and, 82, 1 19 t u t o r i n g a n d , 6 9 , 75—77, 136, 191, 199 v a c a t i o n s and, 4 0 , 9 0 - 9 1 v o u c h e r s a n d , 5 9 - 6 0 , 72, 131 — 3 2 , 195 of W e s t Indian i m m i g r a n t s , 1 10 see also schools, s c h o o l i n g a c h i e v e m e n t , see a c a d e m i c achievement; occupational achievement A c h i e v e m e n t First, 1 3 7 " a c t i n g w h i t e , " 104, 1 4 7 A C T scores, 1 3 A D H D ( a t t e n t i o n deficit hyperactivity d i s o r d e r ) , 5 0 , 186, 2 5 5 a d o p t i o n studies, 21 a c a d e m i c a c h i e v e m e n t in, 35, 120, 183, 241 biracial children in, 9 8 , 1 1 6 - 1 7 , 225-26 black/white IQ g a p in, 9 8 , 1 1 6 17, 2 1 0 , 2 2 3 - 2 4 , 2 2 5 - 2 6 , 230-31 c o r r e l a t i o n s o f I Q and f a m i l y relationships in, 23—25, 2 4 , 29, 238, 2 4 0 - 4 1 environmental modification of I Q in, 2 3 - 2 5 , 2 9 - 3 7 , 9 1 , 183, 196, 2 2 3 - 2 4 , 2 2 5 - 2 6 , 2 3 0 - 3 1 , 238, 240-41 heritability o f I Q in, 2 3 - 2 4 , 2 6 - 2 7 , 3 1 - 3 2 , 33, 196, 2 2 3 24, 2 2 5 - 2 6 , 2 3 0 - 3 1 , 2 4 0 - 4 1 SFS in, 2 9 , 3 2 - 3 7 , 7 8 , 79, 9 1 , 120, 183, 2 2 4 , 2 3 9 , 2 4 0 - 4 1 a d o p t i v e families: I Q and, 32, 36 lack of e n v i r o n m e n t a l v a r i a t i o n in, 26, 2 9 - 3 0 , 3 5 - 3 6 parenting practices o f , 29—30,

INDEX

34, 35, 116-17 affirmative action, 101-2, 232 A f r i c a n A m e r i c a n s , see blacks A f r i c a n cultures, d e f i n i t i o n o f I Q in, 4 A f r i c a n s , 9 3 , 176, 197 facial features o f , 2 2 7 , 231 IQs of, 209-10, 214-15, 222 reaction times o f , 2 2 2 a l c o h o l use, in pregnant w o m e n , 80, 82, 101, 196, 199 A l z h e i m e r ' s disease, exercise and, 185 A . M . T u r i n g A w a r d , 172 analytic intelligence: as c o n d u c i v e to science vs. engineering, 168—70 IQ tests as measure o f , 12, 13, 17 practical intelligence vs., 12 as W e s t e r n characteristic, 162-68 anterior cingulate, 9 anticipation exercises, 185 A p p a l a c h i a n M o u n t a i n s , 104 a priori assumptions, 94 A r a b s , intellectual a c c o m p l i s h m e n t o f , 179 A r i s t o t l e , 1 6 4 - 6 5 , 178 arithmetic tests, 6, 9, 4 7 , 5 4 , 2 1 6 A r m e d Forces Q u a l i f i c a t i o n T e s t , 18, 146, 2 3 3 A r o n s o n , Joshua, 9 5 , 143 Asian A m e r i c a n s : academic achievement of, 1555 7 , 198 hard w o r k emphasized by, 158, 188, 198 IQ of, 156-57, 252 reaction times o f , 221 role of f a m i l y in, 160 S A T scores o f , 1 5 6 - 5 7 t h o u g h t processes o f , 1 67 Asians, 3, 2 5 2 a c a d e m i c achievement o f , 155,

I ndex 158—59, 198 causality judgments o f , 164 cultural values o f , see Chinese cultu re hard w o r k emphasized by, 158, 188, 198 holistic thought as characteristic of, 162-68 IQ as defined by, 4 IQ o f , 154-57, 198, 221, 252 motivation o f , 155, 158-59 reaction times o f , 222 response to failure o f , 158—59, 188, 198 asthma, 82 attentional control, 7, 9, 49—51, 167, 186 attention deficit hyperactivity disorder ( A D H D ) , 50, 186, 255 autism, 10 Babylonian captivity, 174—75 Ball, Harriet, 136 basketball ability, television and, 213 Bayley Mental D e v e l o p m e n t Index, 129 behavior problems: schools and, 104, 1 3 8 - 3 9 , 196 SES and, 8 2 - 8 3 bell curve (normal distribution curve), 3, 2 0 1 - 4 Bell Curve, The (Herrnstein and M u r r a y ) , 36, 39, 74, 94, 209, 21 1 Binet, A l f r e d , 12 biracial children, 98, 1 16-17, 2 2 5 26, 230, 23 1 birth order, 23, 25 birth weight: IQ and, 129-30, 184 mother's exercise regimen and, 184, 199 Black Rednecks and White Liberals (Sowell), 2 4 8 - 4 9

287

blacks: in American history, 105—9 culture o f , 3, 94, 1 18, 197, 213, 223, 2 4 8 - 4 9 as excluded f r o m labor m o v e ment, 108, 109 female, 1 0 2 - 3 female-headed vs. male-headed families o f , 109 historical disadvantages o f , 3, 94,106-9 illegitimacy rate o f , 101 male, 1 0 2 - 3 , 1 0 4 - 5 , 118, 1 4 7 48 northern migration o f , 106, 107-9 parenting practices o f , 1 1 1 — 18, 213, 223 schools and, 1 0 4 - 5 , 1 1 3 - 1 4 , 127, 128, 137, 146, 147 SES o f , 9 5 - 9 6 , 1 0 0 - 1 0 3 , 109, 118 upward SES mobility o f , 101—2, 109, 118, 2 3 2 West Indian, 109-1 1 black/white gap: in income and wealth, 101, 102 in occupational achievement, 94, 95, 100, 1 0 2 - 3 black/white g a p , in academic achievement, 2, 3, 59, 92, 94, 95, 100, 111, 118, 119-52, 197 adoption studies and, 120 charter schools and, 136—41, 149 college and, 1 4 6 - 4 8 cost in reducing o f , 1 4 9 - 5 2 early childhood education and, 1 2 2 - 2 8 , 130, 148 n a r r o w i n g o f , 234—35 N o Child Left Behind A c t and, 119 school-age interventions and, 131-36, 144, 146, 1 4 8 - 4 9

288

black/white gap, in intelligence, 2, 3 , 92, 9 3 - 1 1 8 , 2 0 3 - 4 adoption studies and, 98, 1 16— 17, 210, 2 2 3 - 2 4 , 2 2 5 - 2 6 , 230-31 brain size and, 96, 210, 2 1 9 - 2 0 college and, 1 4 6 - 4 8 correlation of European ancestry and, 9 6 - 9 8 , 197, 2 0 9 - 1 0 , 215, 2 2 3 - 3 2 , 235 as environmentally m o d i f i a b l e , 9 8 - 1 0 0 , 143-44, 197, 2 0 9 - 3 5 genetic arguments f o r , 9 4 - 9 5 , 9 6 - 9 9 , 197, 2 0 9 - 3 5 g factor and, 2 1 0 high school and, 146 IQ scores and, 9 3 - 9 4 , 95, 9 8 - 9 9 , 100, 111 n a r r o w i n g o f , 9 9 - 1 0 0 , 1 18, 1 4 7 - 4 8 , 197, 210, 2 3 2 - 3 4 reaction times and, 210, 2 2 0 - 2 2 regression to the mean and, 210, 222-23 skin c o l o r and, 226—27, 231 Blair, C l a n c y , 48, 49 Blank Slate. The (Pinker), 36 block design tests, 6, 8, 47, 56, 214 b l o o d - g r o u p indicators, I Q and, 97-98, 227-28 Blue R i d g e M o u n t a i n s , 41 bodily kinesthetic intelligence, 14 Bohr, Nils, 170 books, f o r children, 8 7 - 8 8 , 89, 112-13 Borman, Geoffrey, 69 bottlenecks, genetic, 1 74, 1 75 Bouchard, T. J., 239 brain: frontal cortex o f , 167 parietal cortex o f , 167 prefrontal cortex ( P F C ) o f , 9 - 1 2 , 83 brain-imaging studies, 10, 50, 167 brain size: as environmentally modifiable, 220

INDEX

IQ and, 96, 184, 210, 2 1 9 - 2 0 male/female differences in, 219 nutrition and, 220 breast-feeding, IQ and, 81, 101, 185, 196, 199, 246 Bronfenbrenner, Urie, 26 Bronx, N . Y . , 137 Brooklyn, N . Y . , 180 Brooks-Gunn, Jeanne, 1 15 Burakumin, 103 Burt, Cyril, 1, 42 Caesar, Julius, 93w calculus, teaching o f , 54, 142 California Achievement Test ( C A T ) , 124, 135, 140 C a m p b e l l , Frances, 126 C a p r o n , Christiane, 32, 35, 37 caste systems, 103-4 in U.S., 1 0 4 - 9 categorization skills, 113—14, 183, 194,199 Catholic church, 108 Catholics, in Northern Ireland, 103 Cattell Culture Fair Intelligence Test, 75 causality: correlation and, 2 0 7 Flastern vs. Western perception o f , 164 multiple-regression analysis and, 205 as Western preoccupation, 1 70 Ceci, Stephen, 40 charter schools, 1 3 6 - 4 1 , 190 academic achievement and, 60, 72, 132, 137, 139-40, 149, 195 unions and, 151 children: biracial, 98, 116-17, 2 2 5 - 2 6 , 230, 231 books f o r , 8 7 - 8 8 , 89, 1 12-13 categorization skills o f , 1 13—14, 183, 194, 199

I ndex correlation of I Q s between adoptive parents and, 2 4 - 2 5 , 24, 29, 2 4 0 - 4 1 correlation of IQs between birth parents and, 238, 2 4 0 - 4 1 question-and-answer skills o f , 88, 90, 1 13-14 self-control o f , 15-17, 186-88 storytelling skills o f , 1 13 toys o f , 1 12 vocabulary o f , 86, 1 1 1 — 12, 131 see also parenting practices Children of the National Longitudinal Survey of Y o u t h ( C N L S Y ) , 115, 116 China, 168 academic achievement in, 155 Chinese Americans: academic achievement o f , 153, 156 I Q of, 156, 181 occupational achievement o f , 153, 156, 181 reaction times o f , 221 Chinese culture, 157—70 dialecticism in, 165 harmony in, 1 62 holistic thought as characteristic o f , 162-68 intellectual accomplishment in, 159, 178 interdependence in, 160—62 logic in, 165 " m i d d l e w a y " in, 162, 165 pure k n o w l e d g e devalued in, 169 role of family in, 160, 161, 180, 198 science in, 164 Cicero, 93n civil rights movement, 232 class, see caste systems; socioeconomic status class size, 61, 83, 135, 149, 206

289

C N L S Y (Children o f the N a t i o n a l Longitudinal Survey of Y o u t h ) , 115, 1 16 C o c h r a n , G r e g o r y , 176—78 c o d i n g tests, 6, 8, 4 2 - 4 3 , 47, 241 cognitive culture, see parenting practices C o h e n , G e o f f r e y , 145 C o h e n ' s d, 2 0 2 - 3 C o l e m a n report, 155 college: black/white IQ gap in, 146-48 interventions in, 144—46 minorities in, 144—46 C o m e r , James, 70 comprehension tests, 6, 9, 47, 5 2 - 5 3 , 55, 216 comprehensive school r e f o r m , see interventions, whole-school computer-game players, 49—50, 195 computerized instruction, 71, 73, 149, 191, 196 conflict resolution, 185 C o n f u c i a n i s m , 158, 160, 169, 1 7 9 - 8 0 , 252 see also Chinese culture Congress, U.S., 1 19 c o o p e r a t i v e learning, 71—72, 149, 191, 196 correlation coefficient, 3, 204 cost-benefit analysis, 122, 1 5 0 - 5 1 , 195 creative intelligence, 13—14 academic achievement and, 1 3 - 1 4 , 17 IQ tests as p o o r measure of, 17 minorities and, 13—14 occupational achievement and, 1 3 - 1 4 , 17 crime rates, 104, 118, 148 crystallized intelligence, 9 - 1 2 , 47, 5 1 - 5 3 , 2 1 6 - 1 7 , 241 age and, 10, 1 1 cultural bias, in IQ tests, 51, 56, 194,214

290

culture: Asian, see Chinese culture of blacks, 3, 94, 118, 197, 213, 223, 2 4 8 - 4 9 Eastern vs. Western, 157—70 intellectual advantages conferred by, 3, 1 5 7 - 6 2 S A T scores affected by, 16 curiosity, as Western characteristic, 170 curriculum, 7 4 - 7 5 , 132, 134, 195 Dallas, T e x . , 135 Darlington, Cyril, 174 debate, Eastern vs. Western attitude toward, 169-70 dendrites, 176 Descubriendo La Lectura ( R e a d i n g R e c o v e r y ) , 136, 149 Devlin, B., 27, 239 dialecticism, 165 D i a m o n d , A d e l e , 51 Dickens, Charles, 57 Dickens, W i l l i a m , 27, 100, 2 1 2 - 1 3 , 217, 2 3 2 - 3 3 digit span tests, 4 2 - 4 3 Direct Instruction, 70 D o m i n i c a , IQ scores in, 55 drug usage, 118 Dubner, Stephen, 36 D u c k w o r t h , A n g e l a , 16, 187 D u y m e , M i c h e l , 32, 34, 35, 37 d values, 2 0 2 - 3 D w e c k , C a r o l , 143, 189 early childhood education, 1, 121-31 academic achievement and, 122— 28, 128, 130, 148 benefit-cost ratios in, 122, 1 5 0 51 benefits to minorities vs. whites o f , 130 income and wealth and, 124 IQ and, 1 2 1 - 2 7 , 148

INDEX

occupational achievement and, 1 2 3 - 2 4 , 128, 128 SES and, 128, 130, 197 Early H e a d Starr, 122 Earned Income T a x Credit, 152 East Asians, see Asians East/West gap, in academic achievement, 1 5 3 - 7 0 cultural factors in, 158, 159-62, 252, 253 interdependence vs. individualism in, 1 59—62 mathematics skills in, 155, 156 motivation as factor in, 155, 158 Ecuador, 96, 219 educational research, 66, 67—77 on instructional techniques, 71-72 scientific inadequacy o f , 67—69, 140-41 on whole-school interventions, 69-71, 73 educational toys, 125, 183 Education Department, U.S., 73, 191,234 education schools, 65 Education Trust, 132-33 effect sizes, 3, 2 0 2 - 4 fading o f , 121-22 Einstein, Albert, 96 emotional arousal: P F C and, 1 1 - 1 2 , 83 SES and, 83, 101 emotional intelligence, 4, 14 occupational achievement and, 14, 17 emotional support, 64 empathy, in I Q , 4 employees, desirable characteristics o f , 17 employers, stereotyping by, 102 environmental modification: academic achievement and, 2, 3 IQ and, see intelligence, environmental modification of

I ndex within-group vs. between-group, 212-13, 219 Escalante, Jaime, 141-42 Europe, 240 economic status of p o o r and w o r k i n g class in, 79 income inequality in, 83—84 M o o r i s h invasion o f , 93 European Americans: analytic thought as characteristic o f , 162-68 causality perceptions o f , 164 cultural heritage o f , 160—61, 164-66 illegitimacy rate o f , 101 parenting practices o f , 1 1 1—12, 115, 1 1 6 - 1 8 reaction times o f , 221 response to failure o f , 158—59, 188 see also black/white gap; East/ West gap European ancestry, correlation of I Q with, 9 6 - 9 8 , 197, 2 0 9 - 1 0 , 2 1 5 , 2 2 3 - 3 2 , 235 executive functions, 7, 9, 49—5 1, 186 exercise, mental, for fluid intelligence, 4 9 - 5 1 , 185-86 exercise, physical: Alzheimer's disease and, 185 birth weight and, 184, 199 fluid intelligence and, 184-85, 196 extracurricular activities, 139, 183 Eysenck, H. J., 78, 79, 108 factor X , 212, 213 fading, of IQ gains, 121-22, 124, 130, 148 Fagan, Joseph, 98-99 failure, Asian vs. Western response to, 158-59, 188, 198 Falconer's formula, 240 Feinberg, Michael, 136

291

fetal alcohol poisoning, IQ and, 80, 82, 101, 196, 199 Fields M e d a l s , 172 Fisher, Doris and D o n , 137 fluid intelligence, 7 - 1 2 , 4 9 - 5 1 , 195, 214 age and, 10-1 I, 10 emotional arousal and, 1 1 — 12, 83 mental exercises f o r , 49—51, 185-86 in minorities, 12 physical exercise and, 184-85 Raven Matrices as test o f , 7—8, 42, 5 5 - 5 6 , 185, 186, 215, 217, 241 SES and, 12 W I S C tests o f , 8 - 9 , 47, 52, 5 5 - 5 6 , 59, 217, 241 Flynn, James R., 27, 4 4 , 99, 100, 105, 154, 155, 156, 2 1 2 - 1 3 , 214, 2 1 6 - 1 7 , 219, 222, 232-33 !:reakonomics (Levitt and Dubner), 36 free persons of c o l o r , 1 0 5 - 6 , 1 08 frontal cortex, 167 Full Scale I Q , 9 fundamental attribution error, 164 G a l i l e o Galilei, 164 Garden G r o v e , Calif., 153 G a r d n e r , H o w a r d , 14—15 G a r v e y , Marcus, 1 10 Gaucher's disease, 176, 177 general intelligence, see g factor genes, genetics: as trigger of environmental influences, 27—29 see also intelligence, heritability of genetic bottlenecks, 1 74, 1 75 Geography of Thought, The (Nisbett), 253 g e o m e t r y , teaching o f , 54

292

Germans, 168 American GIs and, 97, 2 2 8 - 2 9 g factor (general intelligence), 6 blacks and, 210, 2 1 6 - 1 8 correlation of IQ tests with, 6—7, 216 crystallized intelligence as c o m ponent o f , 9—12 fluid intelligence as c o m p o n e n t of, 7-12 g loadings, 7, 210, 2 1 6 - 1 8 , 2 4 0 - 4 1 Gordon, Hugh, 40 G o t t f r e d s o n , Linda, 4 gQ test, 2 1 7 - 1 8 gratification, delay o f , 15, 16, 187-88 Great Britain, 225 canal boat communities in, 104 intellectual accomplishment in, 179, 198 Great Depression, 109 Greeks, ancient: individualism as ideal o f , 1 6 0 - 6 1 logic as invention o f , 165—66 pure k n o w l e d g e valued by, 169 scientific thought o f , 164—65 Green, D a v i d , 1 90 H a m r e , Bridget, 63, 65 Hanushek, Eric, 62 hard w o r k : academic achievement and, 158, 188-90 Eastern vs. Western attitudes t o w a r d , 158, 188 IQ as malleable through, 143, 158,188-90 H a r d y , Jason, 176 harmony, as Eastern value, 162 H a r p e n d i n g , H e n r y , 176 Harris, Judith Rich, 36 H a r t , Betty, 86, 116 H a s i d i m , 180 H e a d Start, 1 2 1 - 2 2 , 150 health care, 1 25

INDEX

health insurance, 84 health problems: academic achievement and, 80-81 Head Start and, 121 SES and, 8 0 - 8 1 , 101 Heath, Shirley Brice, 87, 90, 1 12, 114-15, 181 H e b e r , Rick, 124-25 Hebrides Islands, 104 H e c k m a n , James, 150 height, as independently heritable and m o d i f i a b l e , 38 hereditarians, see strong hereditarians heritability: of intelligence, see intelligence, heritability of in populations vs. individuals, 22 Heritage Foundation, 132 Herrnstein, Richard, 36, 39, 7 4 - 7 5 , 9 4 - 9 5 , 129, 146, 154, 196, 209, 21 1, 215, 218, 221, 223, 224, 232, 235, 252 heuristics, 195 Hispanics: academic achievement of, 120, 133-34, 141-42 early childhood education and, 130 I Q o f , 120 schools and, 137, 141-42 holistic thought: as Asian characteristic, 162—68 as conducive to engineering vs. science, 168—70 Holland, 240 H o l l a n d , Cynthia, 9 8 - 9 9 H O M F 1 ( H o m e Observation for Measurement of the Environment), 2 9 - 3 0 , 1 1 5 - 1 6 h o m e visitations, 126—27, 130—31, 136-37, 197 H o n g K o n g , 167—68 H o u s t o n , T e x . , 136, 137

I ndex Humphreys, Joe, 1 71 hypothesis testing, 195 identical twins, impact of heredity vs. environment o n , 23—24, 2 5 - 2 6 , 3 1 - 3 2 , 2 1 1 - 1 3 , 239, 240 Ignatiev, N o e l , I 08 I H D P (Infant Health and D e v e l o p ment P r o g r a m ) , 115, 116 IJzendoorn, van, M . H . , 241 illegitimacy rate: in blacks vs. whites, 101 I Q and, 19, 7 9 SF.S and, 19, 101 inbreeding depression, 210, 218—19 income: black/white gap in, 101, 102 early childhood education and, 124 I Q and, 19, 7 9 as proxy for other socioeconomic factors, 1 9 of West Indian immigrants, 1 10 income inequality: academic achievement and, 85, 152 in U.S. vs. Europe and Japan, 8 3 - 8 4 , 152 independent (predictor) variables, 204, 2 0 7 India: caste system in, 103—4 intellectual accomplishment in, 178 individualism, interdependence vs., 159-62, 1 6 8 - 6 9 Indochinese boat people, 153, 158 Industrial Revolution, 161 inequality of Man, The (Eysenck), 78 ' Infant Health and Development Program ( I H D P ) , 115, 116 information tests, 6, 9, 47, 53—54, 214, 216

293

inhibitory control, 7, 9, 50, 51, 185-86 instructional support, 64 instructional techniques, 7 1 - 7 2 , 73, 149, 191, 195, 196 integrated learning systems, 71 intelligence: academic achievement and, 5, 1 3 - 1 4 , 17, 55, 156, 182, 187, 193-99 o f Africans, 2 0 9 - 1 0 , 2 1 4 - 1 5 ,

222 analytic, see analytic intelligence of Ashkenazi Jews, 172-78, 198 of Asian Americans, 156—57, 252 of Asians, 1 5 4 - 5 7 , 198, 221, 252 of black females vs. males, 103 black/white g a p in, see black/ white gap, in intelligence bodily kinesthetic, 14 brain size and, 96, 184, 210, 2 I 9-20 of Chinese Americans, 156, 181 correlation of European ancestry with, 9 6 - 9 8 , 197, 2 0 9 - 1 0 , 2 1 5 , 2 2 3 - 3 2 , 235 correlations of family relationships with, 2 3 - 2 5 , 24, 29, 238 creative, see creative intelligence definitions o f , 1, 4 - 5 , 195 e m o t i o n a l , 4, 14 fluid, see fluid intelligence general, see g factor generational increases in, 4 3 - 5 6 , 99, 181, 1 9 4 - 9 5 , 214, 217, 218-19, 232-34 Hispanic/white gap in, 120 illegitimacy rate and, 19, 7 9 impact of television on, 53 inbreeding depression and, 210, 218-19 income and, 19, 7 9, 152

294

intelligience (continued) as independently heritable and m o d i f i a b l e , 3 8 , 194 interventions a n d , 1 - 3 , 21 of Irish, 108 lay understanding o f , 5 measurement o f , see I Q scores; I Q tests of minorities, 2, 3, 13—14, 197 of m o t h e r s , 123, 125, 126, 151 musical, 14 occupational achievement and, 56 parenting practices and, 1 16—18, 182-83 personal, 14-15 personal c o n t r o l o f , 143, 158, 1 8 8 - 9 0 , 198, 199 phenotypic, 1 8 I practical, see practical intelligence praising o f , 1 8 8 - 9 0 as predictor of life o u t c o m e s , 17-20 self-control and, 186-88 skin c o l o r and, 226—27 social d e m a n d s o n , 2 , 1 9 4 - 9 5 strategies f o r increasing o f , 182— 92, 198-99 intelligence, e n v i r o n m e n t a l m o d i f i c a t i o n o f , 1—3, 20 in a d o p t i o n studies, 23—25, 2 9 - 3 7 , 91, 183, 196, 2 2 3 - 2 4 , 2 2 5 - 2 6 , 2 3 0 - 3 1 , 238, 240-41 in A s h k e n a z i Jews, 1 7 9 - 8 1 , 198 b e t w e e n - f a m i l y , 22—23, 25, 29-30, 242 b i o l o g i c a l f a c t o r s in, 2 2 , 2 7 , 4 5 , 4 8 , 55, 79, 8 0 - 8 2 , 101, 196 birth w e i g h t and, 1 2 9 - 3 0 , 184 black/white g a p in, see black/ w h i t e g a p , in intelligence breast-feeding and, 81, 101, 185, 196, 199, 2 4 6

INDEX early c h i l d h o o d education and, 1 2 1 - 2 7 , 148 estimates o f percentage o f , 2 1 , 25, 2 8 - 3 0 , 3 6 f a d i n g in, 1 2 1 - 2 2 , 124, 130, 148 fetal a l c o h o l p o i s o n i n g and, 80, 8 2 , 101, 196, 199, 2 2 0 genes as triggers o f , 27—29 hard w o r k and, 143, 158, 1 8 8 90 H e a d Start and, 1 2 1 heredity vs., 2 1 - 3 8 , 39, 143, 148, 1 9 3 - 9 8 , 2 0 9 - 3 5 interventions and, 143—44 nutrition and, 4 5 , 4 8 , 55, 80, 101 pre- and perinatal, 2 2 , 27, 80, 82, 101, 1 8 3 - 8 4 , 196, 199, 220, 239 s c h o o l i n g in, 3 9 - 4 3 , 4 6 , 55, 56, 75, 1 9 5 - 9 7 SES a n d , 2, 3, 18, 3 1 - 3 7 , 5 6 , 7 8 - 9 2 , 1 0 0 - 1 0 3 , 183, 194, 196-97, 242 social f a c t o r s in, 22—23, 79, 82-92, 101-3 stress in, 1 1 - 1 2 , 8 2 - 8 3 , 1 8 2 - 8 3 in twin studies, 23—24, 26—27, 3 1 - 3 2 , 2 1 1 - 1 3 , 239, 240 vacations and, 4 0 , 9 0 - 9 1 w i t h i n - f a m i l y , 23, 25, 2 7 , 3 3 , 239 intelligence, heritability o f , 1—2, 20, 93 in a d o p t i o n studies, 2 3 - 2 4 , 2 6 - 2 7 , 3 1 - 3 2 , 3 3 , 196, 2 2 3 24, 2 2 5 - 2 6 , 2 3 0 - 3 1 , 2 4 0 - 4 1 Ashkenazi Jews and, 173—78, 181 black/white g a p and, 9 4 - 9 5 , 9 6 - 9 9 , 1 1 8, 2 0 9 - 3 5 e n v i r o n m e n t a l m o d i f i c a t i o n vs., 2 1 - 3 8 , 39, 143, 148, 1 9 3 - 9 9 , 209-35

I ndex estimates of percentage o f , 2 1 - 2 7 , 3 1 - 3 7 , 38 population variation and, 30-32 SES and, 27, 3 1 - 3 7 , 78, 91, 96, 120, 193-94, 196, 197, 239-40 in twin studies, 2 3 - 2 4 , 2 6 - 2 7 , 31-32, 2 1 1 - 1 3 , 239, 240 interdependence, individualism vs., 159-62, 168-69 interventions, 142—46 academic achievement and, 1—2, 70, 73, 131-36, 144, 146, 148-49, 197-98 college-level, 144-46 I Q and, 1 - 3 , 21 whole-school, 6 9 - 7 1 , 73, 132, 134-36, 149, 195 see also charter schools; early childhood education IQ scores: black/white gap in, 9 3 - 9 4 , 95, 9 8 - 9 9 , 100, 111, 2 0 3 - 4 in Dominica, 55 intelligence and, 182 in Kenya, 55 S A T scores and, 15—16, 157 in Scandinavia, 55 in Venezuela, 75, 196 IQ tests, 2, 4, 5 - 7 , 93, 195 correlation between, 5 - 6 , 9 cultural bias in, 51, 56, 194, 209, 214 d values in, 203 effect sizes in, 2 0 3 - 4 X factor correlation with, 6 - 7 as measure of analytic intelligence, 12, 13, 17 of memory, 6 of mental speed, 6, 8 performance, 9, 4 6 - 4 7 , 4 9 - 5 1 , 214, 241 as poor measure of creative intelligence, 17

295

as predictors of academic achievement, 5, 12, 16, 17, 4 5 - 4 6 , 51 as predictors of occupational achievement, 45—46 prior knowledge as factor in, 98-99 problem-solving and, 75, 196 re-norming of, 43—44, 233 of spatial perception, 6 of spelling ability, 6 standard deviation in, 5, 202, 202 stereotype threat in, 95, 147-48 of verbal knowledge, 6, 9, 47, 5 1 - 5 3 , 9 8 - 9 9 , 214, 241 of visual perception, 6, 252 see also specific tests Ireland: Northern, 103 p o o r and w o r k i n g class in, 107 Irish: academic and occupational success o f , 1 08 IQs of, 108, 222 reaction times of, 222 Irish Americans: historical disadvantages o f , 105-7 upward SES mobility of, 108 Islam, Sephardic Jews and, 178 Israel, 103 Italian Americans, 104 Italy, intellectual accomplishment in, 179, 198 Jamestown colony, 105 Japan: Burakumin in, 103 economic status of poor and w o r k i n g class in, 79 hierarchical social structure o f , 168 income inequality in, 83—84 teachers in, 1 59

296

Japanese: academic achievement of, 1545 5 , 158 e n g i n e e r i n g p r o w e s s o f , 168 reaction times o f , 221—22 Japanese A m e r i c a n s , a c a d e m i c a c h i e v e m e n t o f , 156 Jencks, C h r i s t o p h e r , I 1 9 Jenkins, M . D . , 2 2 9 Jensen, A r t h u r , 21, 2 4 , 25, 27, 95, 96, 119, 154, 2 0 9 , 21 1, 2 1 5 , 217, 218, 219, 221, 222, 223, 224, 225, 232, 233, 235, 240, 241 Jews, A s h k e n a z i , 3 , 1 7 1 - 8 1 a c a d e m i c a c h i e v e m e n t o f , 171 — 7 2 , 1 7 9 - 8 1 , 198 athletic success o f , 180 genetic illnesses o f , 176—77 i m p o r t a n c e o f f a m i l y t o , 180, 198 N o b e l Prizes w o n by, 171—72 occupational achievement of, 172, 177, 180 universal m a l e literacy o f , 171, 175, 177 w e a l t h o f , 172, 176 J e w s , A s h k e n a z i , I Q o f , 172—78, 254 B a b y l o n i a n c a p t i v i t y and, 1 7 4 75 as culturally d e t e r m i n e d , 179— 8 1 , 198 as genetically determined, 173—78 literacy t h e o r y o f , 175 " m a r r y the s c h o l a r " t h e o r y o f , 175 o c c u p a t i o n a l pressure and, 176— 78 persecution and, 174 spatial-relations ability in, 2 5 4 Jews, Sephardic, 103, 1 7 7 - 7 8 I Q o f , 173, 178 under Islamic rule, 178 Jim C r o w , 107

INDEX Kansas C i t y , M o . , 5 8 K e n y a , I Q scores in, 5 5 , 2 1 5 K I P P ( K n o w l e d g e I s P o w e r Prog r a m ) , 1 3 6 - 4 1 , 149, 1 5 1 - 5 2 , 190 K l i n g b e r g , T o r k e l , 186 knowledge: acquisition o f , 4, 9 as i m p a r t e d by m e d i a , 194—95 W e s t e r n emphasis o n , 4 - 5 , 169 K n o w l e d g e Is Power Program ( K I P P ) , 1 3 6 - 4 1 , 149, 1 5 1 - 5 2 , 190 K o r e a , 168 K r u e g e r , A l a n , 61 K u l i k , James, 71 labor m o v e m e n t , blacks e x c l u d e d f r o m , 108, 109 L a n d r y , Susan, 130 I.areau, A n n e t t e , 87 lead p o i s o n i n g , I Q and, 80, 82, 101 L e p p e r , M a r k , 7 5 - 7 7 , 190, 191 L e v i n , D a v i d , I 36 L e v i t t , Steven, 36 Lewontin, Richard, 212 life o u t c o m e s : IQ as predictor o f , 17-20 multiple-regression analysis o f , 17-18 see also a c a d e m i c achievement; occupational achievement limbic lobe, 11, 183 literacy: of A s h k e n a z i Jews, 171, 175, 177 SES a n d , 89 Locurto, Charles, 36 L o e h l i n , J. C . , 2 2 8 logicin Chinese culture, 165 as Greek i n v e n t i o n , 165—66 in science, 169 L y n n , R i c h a r d , 154, 215

I ndex M c C a r t n e y , Kathleen, 27 M c D o n a l d ' s , 195 M c G r a w - H i l l publishing c o m p a n y , 70 M c G u e , M a t t , 239 M c L o y d , Vonnie, 8 3 malaria, 176 M a o r i , 103 " m a r r y the scholar," 175 Masuda, T a k a h i k o , 162, 164 mathematics skills: Fast/West gap in, 155 narrowing of black/white gap in, 234—35 teaching o f , 54, 1 3 5 - 3 6 , 141-42, 195 media: knowledge imparted by, 194-95 see also television medical care, SFIS and, 81 meditation, 186 memory, 4 stress and, 1 83 tests o f , 6 w o r k i n g , 7, 9, 4 9 , 50, 186 mental retardation, 124—25, 126 mental speed, 4 tests o f , 6, 8 metaphorical thinking, 52, 1 13 middle class: blacks in, 109, I 18, 232 definition o f , 79 early childhood education and, 130 IQ variances as genetically determined within, 1 9 3 - 9 4 as overrepresented in adoption studies, 3 1 - 3 2 , 35 parenting practices o f , 87—88 see also s o c i o e c o n o m i c status (SES) " m i d d l e w a y , " in Chinese culture, 162, 165 M i l w a u k e e , Wis., 124-26, 133

297

M i l w a u k e e Project, 124-26, 152 minimum w a g e , 84, 152 M i n n e a p o l i s , M i n n . , 154—55 minorities: academic achievement o f , 2, 3, 1 3 - 1 4 , 104, 131, 145, 146, 197 caste-like, 103—4 in college, 144—46 crime rates of, 1 04 e f f o r t optimism lacking in, 104 fluid intelligence in, 12 involuntary vs. a u t o n o m o u s , 104 IQ o f , 2, 3, 13-14, 197 occupational achievement o f , 13-14 schools and, 6 1 SES o f , 119 see also specific ethnic groups Mischel, W a l t e r , 15, 187-88 " M i s s A , " 6 2 - 6 3 , 135 M o o r e , Elsie, 98, 1 1 6 - 1 7 , 2 2 5 - 2 6 Moors: Europe invaded by, 93 intellectual accomplishment o f , 178-79 mothers, IQs o f , 123, 125, 126, 151 motivation: academic achievement and, 16, 104-5, 147, 155 of Asians, 155, 1 5 8 - 5 9 practical intelligence and, 12 of young black males, 102—3, 104-5 m o v e m e n t time, 222 M o y n i h a n , Patrick, 102 Mueller, Claudia, 189 multiple-regression analysis, 58, 61, 204-6 author's skepticism o f , 3, 18, 40, 205,206 causality and, 205 of life outcomes, 17—18

298

M u r r a y , Charles, 1 8 - 2 0 , 3 6 , 3 9 , 4 5 , 5 6 , 9 4 - 9 5 , 119, 129, 146, 154, 175, 2 0 9 , 2 1 1 , 2 1 5 , 2 1 8 , 221, 223, 224, 232, 235, 252 musical intelligence, 14 M y e r s o n , Joel, 146—47 M y r d a h l , G u n n a r , 103 N A E P ( N a t i o n a l Assessment o f Educational Progress), 53, 100, 2 3 4 - 3 5 n a r r a t i v e skills, 1 13 N a t i o n a l Assessment o f Educational Progress ( N A E P ) , 5 3 , 100, 234-35 N a t i o n a l Institute o f C h i l d H e a l t h and H u m a n D e v e l o p m e n t , 6 3 N a t i o n a l Institutes o f H e a l t h , 2 0 5 N a t i o n a l L o n g i t u d i n a l Survey o f Y o u t h , 18, 146 nerve c o n d u c t a n c e speed, 2 1 6 neurons, neural branching, 177, 184 New York Times, 133-34 N e w Z e a l a n d , 103 N i e m a n n - P i c k disease, 176 N o b e l Prizes, 168, 1 7 1 - 7 2 N o C h i l d L e f t Behind A c t ( 2 0 0 2 ) , 119, 197 n o r m a l distribution c u r v e (bell c u r v e ) , 3, 2 0 1 - 4 , 202 N o r t h e r n Ireland, C a t h o l i c s in, 103 northern m i g r a t i o n , of blacks, 106, 107-9 N o r t h Star, 137 Nurture Assumption, The (Harris), 36 nutrition, 125 brain size and, 2 2 0 I Q a n d , 4 5 , 4 8 , 5 5 , 80, 101 o b j e c t assembly tests, 6, 8, 4 7 , 5 6 , 214 occupational achievement: of A s h k e n a z i Jews, 172, 177, 180

INDEX black/white g a p in, 94, 95, 100, 102-3 c o r r e l a t i o n o f a c a d e m i c achievement w i t h , 17, 157 creative intelligence and, 13—14, 17 early c h i l d h o o d education and, 1 2 3 - 2 4 , 128, 128 e m o t i o n a l intelligence and, 14, 17 of free persons of c o l o r , 1 06 impact o f teachers o n , 6 3 I Q gains and, 5 6 IQ tests as predictors o f , 45—46, 51 of minorities, 13—14 parenting practices and, 79, 85-86 practical intelligence and, 13, 17 SES and, 8 5 - 8 6 of W e s t Indian immigrants, I 10 O g b u , J o h n , 93, 1 0 3 - 5 O h i o State University, 136 Organisation for Economic C o o p e r a t i o n and D e v e l o p m e n t , 84 O t i s - L e n n o n School A b i l i t y T e s t , 75 o u t c o m e ( t a r g e t ) variables, 204—5, 207 overachievement: of A s h k e n a z i Jews, 181 of Asian A m e r i c a n s , 156—57 O y s e r m a n , D a p h n a , 144 parenting practices: a c a d e m i c a c h i e v e m e n t and, 79, 8 8 , 9 0 , 183 of a d o p t i v e families, 29—30, 34, 35, 1 1 6 - 1 7 of blacks, 1 1 1 - 1 8 , 213, 2 2 3 delay o f g r a t i f i c a t i o n m o d e l i n g in, 188 e n c o u r a g e m e n t vs. r e p r i m a n d in, 8 6 - 8 7 , 1 1 6 - 1 7 , 131, 182, 197

I ndex extracurricular activities and, 183 home visitations and, 126—27, 130-31, 197 I Q and, 116-18, 1 8 2 - 8 3 of middle class, 8 7 - 8 8 occupational achievement and, 79, 8 5 - 8 6 question-and-answer skills taught in, 88, 90, 1 1 3 - 1 4 reading to children in, 87—88, 112-13, 116, 182 SES and, 79, 8 2 - 8 3 , 8 5 - 9 2 , 101, 125, 183 verbal behavior in, 86, 87—89, 111-13, 1 14, 131, 182 of whites, 1 1 1 - 1 2 , 115, 1 16-18 of w o r k i n g class, 8 8 - 8 9 parents: correlation of I Q s between adopted children and, 24—25, 24, 29, 2 4 0 - 4 1 see also mothers parietal cortex, 167 percentiles, 2 0 1 - 4 , 202 performance I Q , 9 , 4 6 - 4 7 , 4 9 - 5 1 , 214, 241 Perry Preschool P r o g r a m , 123, 128, 150, 152 persecution, of Ashkenazi Jews, 174 personal intelligences, 14—15 pesticides, IQ and, 8 1 PFC, see prefrontal cortex Phillips, Meredith, 1 15 Pianta, Robert, 63, 65 Pickwick Papers, The (Dickens), 57 picture arrangement tests, 6, 8, 47, 56, 214 picture completion tests, 6, 8, 47, 56 Pinker, Steven, 36 Plato, 178 pollution, SES and, 82, 101, 196 poor: definition o f , 79

299 early c h i l d h o o d education and, 130, 197 e c o n o m i c status o f , 79, 92 IQ variances as environmentally determined within, 194 see also s o c i o e c o n o m i c status (SES) Posner, M i c h a e l , 186 P o w e l l , C o l i n , 110 practical intelligence, 4, 12—14, 56 academic achievement and, 13, 17 analytic intelligence vs., 12 IQ tests as measure o f , 17, 75 minorities and, 13—14 motivation and, 12 occupational achievement and, 13, 17 praise: of intelligence, 1 8 8 - 9 0 rewards vs., 190 predictor (independent) variables, 204, 2 0 7 prefrontal cortex ( P F C ) , 9 - 1 0 emotional arousal and, 1 1 — 12, 83, 183 Prince E d w a r d C o u n t y , V a . , 4 1 principals, 65, 66, 73, 132, 137, 138, 142, 191 probability theory, 195 problem-solving, 4, 7, 117, 184, 196, 213 exercise and, 184 P F C and, 10 in Raven M a t r i c e s tests, 8, 10 schooling and, 39, 7 4 - 7 5 visual, 6, 4 8 - 4 9 , 48, 195 Project Care, 129 Project S E E D , 1 3 5 - 3 6 , 149 quantum physics, 170 race: SES and, 80 see also black/white g a p ; specific racial groups

300

racial ancestry, c o r r e l a t i o n o f I Q w i t h , 9 6 - 9 8 , 197, 2 0 9 - 1 0 , 215, 223-32, 235 racial p r e j u d i c e , 105, 1 18 Raleigh, N . C . , 133-34 R a m e y , C r a i g , 126 R a v e n , J., 4 2 R a v e n , John C . , 8 , 4 2 R a v e n Progressive M a t r i c e s , 7, 9, 3 9 , 4 3 , 4 7 , 7 5 , 189, 2 1 5 c o m p u t e r - g a m e players and, 5 0 , 195 cultural bias in, 5 1 , 5 6 , 194, 2 1 4 fluid intelligence a n d , 7—8, 4 2 , 5 5 - 5 6 , 185, 186, 2 1 5 , 2 1 7 , 241 g e n e r a t i o n a l c h a n g e in, 46—49, 51,55,194-95 m e d i t a t i o n and, 186 as p r e d i c t o r of a c a d e m i c and o c c u p a t i o n a l a c h i e v e m e n t , 51 p r o b l e m - s o l v i n g in, 8, 10 reaction times, black/white I Q g a p and, 2 1 0 , 2 2 0 - 2 2 reading: by parents to children, 87—88, 1 1 2 - 1 3 , 116 teaching o f , 136 Reading Recovery (Descubriendo La L e c t u r a ) , 136, 149 reasoning skills, 4, 7, 8, 9 R e c o n s t r u c t i o n , 107 redlining, 101 R e e v e s , D o u g l a s , 133 regression to the m e a n , black/white I Q g a p and, 2 1 0 , 2 2 2 - 2 3 Renaissance, 161, 179 Republic, The ( P l a t o ) , 169 rewards: in K I P P s c h o o l s , 137, 138, 190 praise vs., 1 90 rhetoric, 1 6 9 - 7 0 R i s l e y , T o d d , 86, 1 16 R o m e , ancient, 161, 179 Roots 6c Wings, 6 9 - 7 0

INDEX Rothstein, R i c h a r d , 132—33 R u e d a , R o s a r i o , 50, 185 R u s h t o n , J. Philippe, 95, 9 6 , 154, 2 0 9 , 2 1 5 , 2 1 8 , 2 1 9 , 2 2 1 , 222, 2 2 3 , 2 2 4 , 2 2 5 , 2 3 2 , 2 3 3 , 235 S a l o v e y , Peter, 14 San Francisco Bay A r e a , K I P P schools in, 137—40 Sarason, S e y m o u r , 180 S A T scores, 13 of Asian A m e r i c a n s , 156—57 cultural impact o n , 16 delay of g r a t i f i c a t i o n and, 15, 187 e f f e c t sizes in, 2 0 3 IQ scores and, 15—16, 157 Scandinavia, 2 4 0 i n c o m e distribution in, 152 intellectual a c c o m p l i s h m e n t in, 179 IQ scores in, 55 skill disparity in, 8 4 - 8 5 Scarr, Sandra, 21, 2 7 , 2 2 3 - 2 4 , 225 School D e v e l o p m e n t P r o g r a m , 7 0 schools, s c h o o l i n g , 57—77, 92 at-risk students in, 63—65 b e h a v i o r p r o b l e m s and, 104, 1 3 8 - 3 9 , 196 blacks and, 1 0 4 - 5 , 1 1 3 - 1 4 , 127, 128, 137, 146, 147, 197 charter, 6 0 , 72, 132, 1 3 6 - 4 1 , 149, 190, 195 class size and, 6 1 , 83, 135, 206 curriculum in, 7 4 - 7 5 , 132, 134 "effective," 66-67, 73 e m o t i o n a l support in, 6 4 , 135 extracurricular activities and, 139 H i s p a n i c s and, 137, 1 4 1 - 4 2 impact o n I Q o f , 1 - 3 , 3 9 - 4 3 , 4 6 , 5 5 , 5 6 , 75, 1 9 5 - 9 7 instructional support in, 64 instructional techniques and, 7 1 - 7 2 , 73, 149, 191, 195, 196

I ndex interventions in, see interventions mathematics instruction in, 54, 135-36, 141-42, 195 minorities and, 61 N o Child Left Behind Act and, 119, 1 97 principals in, 65, 66, 73, 132, 137, 138, 142, 191 problem-solving skills and, 39, 74-75 reading instruction in, 136 research and, see educational research rewards and penalties in, 137, 138-39, 190 SES and, 61, 6 6 - 6 7 , 83, 101, 131, 137, 196 spending and, 58—59, 72, 131 student turnover in, 82, 119, 196 teachers and, see teachers time spent in, 40—41, 55, 195 vouchers and, 5 9 - 6 0 , 72, 1 3 1 32, 195 young black males in, 104—5, 147—48 see also academic achievement; college; early childhood education Schweinhart, Lawrence, 123 science: curiosity and, 170 in Eastern vs. Western culture, 164-65, 168-70, 198 scientific method, as lacking in educational research, 67—69 Scotland, intellectual accomplishment in, 179, 198 SEED, Project, 135-36, 149 segregation, 106 self-control, 15-17, 186-88 self-esteem, 147-48 self-selection bias, 3, 59, 68, 130, 132, 140, 141, 2 0 6 - 8 , 2 3 1 32 Seligman, M a r t i n , 16, 187

301

Sendai, Japan, 154—56 Sesame Street ( T V p r o g r a m ) , 53 sharecropping, 107 Shuey, A u d r e y , 2 2 7 sickle-cell anemia, 176 similarities tests, 6, 9, 4 7 , 51—52, 55, 216 skill disparity, SES and, 8 4 - 8 5 skin c o l o r , IQ and, 226—27, 231 slavery, 106-7, 110, 2 3 1 - 3 2 Slavin, R o b e r t , 72 s o c i o e c o n o m i c status (SES): academic achievement and, 2, 3, 18, 3 3 - 3 4 , 63, 85, 9 0 - 9 1 , 134,157 in adoption studies, 29, 32—37, 78, 79, 91, 120, 183, 224, 239, 2 4 0 - 4 1 behavior problems and, 8 2 - 8 3 biological factors o f , 79, 8 0 - 8 2 , 196 of blacks, 9 5 - 9 6 , 1 0 0 - 1 0 3 , 109, 118 early childhood education and, 128y 130, 197 and environmental m o d i f i c a t i o n of I Q , 2, 3, 18, 3 1 - 3 7 , 56, 7 8 - 9 2 , 1 0 0 - 1 0 3 , 183, 194, 196-97, 242 fluid intelligence and, 12 and heritability of I Q , 27, 3 1 - 3 7 , 78, 91, 96, 120, 1 9 3 94, 196, 197, 2 3 9 - 4 0 income inequality in, 83—84, 120, 149, 197 literacy gap in, 89 of minorities, 1 19 occupational achievement and, 85-86 parenting practices and, 79, 8 2 - 8 3 , 8 5 - 9 2 , 101, 125, 183 race and, 80 schools and, 66—67, 83, 101, 131,137 skill disparity in, 8 4 - 8 5

302

s o c i o e c o n o m i c status (SES) (continued) skin c o l o r a n d , 2 2 6 social f a c t o r s o f , 7 9 , 8 2 - 9 2 , 1 1 8 stress and, 82—83 u p w a r d m o b i l i t y o f blacks in, 1 0 1 - 2 , 109, 1 18, 2 3 2 see also m i d d l e class; p o o r Socrates, 1 69 Socratic q u e s t i o n i n g , 135 South K o r e a , 85 S o w e l i , T h o m a s , 9 3 , 105, 1 10, 248-49 Spain, intellectual a c c o m p l i s h m e n t in, 178 spatial p e r c e p t i o n , tests o f , 6 speed of reasoning, see mental speed spelling tests, 6 s p h i n g o l i p i d s , 176—77 SRI I n t e r n a t i o n a l , K I P P schools study o f , 1 3 7 - 4 1 Stand and Deliver ( m o v i e ) , 141—42 standard d e v i a t i o n ( S D ) , 3, 5, 2 0 1 - 4 , 202 Stanford Achievement Test ( S A T 10), 1 3 9 - 4 0 Stanford-Binet IQ test, 123, 125, 233 re-norming of, 44 statistical s i g n i f i c a n c e , 3, 208 statistical terms, 2 0 1 - 8 Steele, C l a u d e , 95 s t e r e o t y p e threat, in IQ tests, 95, 147—48 stereotyping: of W e s t Indians, 1 1 1 of y o u n g black males, 102 Sternberg, R o b e r t , 4 , 1 2 - 1 4 Stevenson, H a r o l d , 154, 155 stimulus d i s c r i m i n a t i o n , 185 S t o o l m i l l e r , M i k e , 29, 3 0 , 3 1 , 3 2 , 34, 239 storytelling, 1 1 3 stress, 1 8 2 - 8 3

INDEX m e m o r y and, 183 P F C and, 1 1 - 1 2 , 183 SES and, 8 2 - 8 3 strong hereditarians, 2 3 - 2 4 , 2 5 - 2 6 , 2 7 , 3 5 , 39, 79, 91, 98, 146, 193, 2 2 2 , 241 structured d y a d m e t h o d , of instruction, 72 Student T e a m s A c h i e v e m e n t D i v i sions, 72 student t u r n o v e r , a c a d e m i c achievement a n d , 82, 1 1 9 Study of F'arly C h i l d C a r e , 63 Success f o r A l l , 6 9 - 7 0 s u m m e r vacations, 4 0 , 90—91 T a i p e i , T a i w a n , 154—55 Taiwan, 154-55 T a l m u d , 171, 175 T a n g , Y i - Y u a n , 186 target ( o u t c o m e ) variables, 2 0 4 - 5 , 207 T a y l o r , H . F., 2 3 9 T a y - S a c h s disease, 176 teachers, 6, 83, 1 19, 132, 138, 149, 151 a c a d e m i c a c h i e v e m e n t and, 6 1 - 6 6 , 7 3 , 1 3 4 - 3 5 , 191, 196 burnout o f , 139 c e r t i f i c a t i o n and credentialization o f , 6 1 , 73, 134, 1 9 1 - 9 2 , 195 incentives f o r , 65—66, 7 3 , 149, 191 in Japan, 1 59 o c c u p a t i o n a l achievement and, 63 pay o f , 6 5 - 6 6 , 151 training o f , 65, 6 9 , 192 unions and, 151, 191 T e a c h f o r A m e r i c a , 138 television: basketball ability and, 2 1 3 impact o n I Q o f , 5 3 see also media

I ndex T e x a s Assessment o f A c a d e m i c Skills ( T A A S ) , 144 T h i r d International M a t h e m a t i c s and Science study, 153 thought, holistic vs. analytic, 162-68 T I M S S ( T r e n d s in International M a t h e m a t i c s and Science Study), 58 toys, 1 1 2 educational, 125, 183 T u r k h e i m e r , F.ric, 31, 2 3 9 - 4 0 tutoring, 136 effectiveness o f , 7 5 - 7 7 , 191, 199 in w h o l e - s c h o o l interventions, 69 T w a i n , M a r k , 171 twins, identical, impact of heredity vs. e n v i r o n m e n t o n , 23—24, 26-27, 3 1 - 3 2 , 21 1-13, 239, 240 unions: blacks e x c l u d e d f r o m , 108, 109 teachers and, 151, 191 United States: academic a c h i e v e m e n t in, 57 caste system in, 104—9 e c o n o m i c status of p o o r and w o r k i n g class in, 7 9 , 92 history of blacks in, 105—9 i n c o m e inequality in, 83, 120, 149, 152 intellectual a c c o m p l i s h m e n t in, 179, 198 uterine e n v i r o n m e n t , 27, 2 3 9 vacations, 4 0 , 9 0 - 9 1 Vanhanen, Tatu, 215 variables, in statistical analysis, 204-5, 207 V e n e z u e l a , curriculum enrichment in, 7 4 - 7 5 , 196 verbal b e h a v i o r , in parenting practices, 86, 8 7 - 8 9 , 1 1 1 - 1 3 , 114, 131, 182

303

Verbal I Q , 6, 9, 47, 5 1 - 5 3 , 9 8 - 9 9 , 214,241 verbal k n o w l e d g e , tests o f , see V e r bal I Q V e r n o n , Philip, 154 v i d e o - g a m e players, 4 9 visual p r o b l e m - s o l v i n g , 6 , 4 8 - 4 9 , 48, 195 v o c a b u l a r y tests, 6, 7, 9, 4 7 , 5 3 , 214,216 v o u c h e r s , 5 9 - 6 0 , 7 2 , 1 3 1 - 3 2 , 195 W a k e County, N . C . , 133-34, 250 W a l t o n , G r e g o r y , 145 W a s h i n g t o n , D . C . , free blacks in, 106 wealth: of A s h k e n a z i Jews, 172, 176 black/white g a p in, 101 early c h i l d h o o d e d u c a t i o n and, 124 W e c h s l e r A d u l t Intelligence Scale, 125,233 re-norming of, 44 W e c h s l e r Intelligence Scale f o r C h i l dren ( W I S C ) , 6, 6, 126, 2 0 2 , 233 A r i t h m e t i c test o f , 6, 9, 4 7 , 5 4 ,

216 Block Design test o f , 6, 8, 4 7 , 56 C o d i n g lest o f , 6, 7, 8, 47, 2 1 6 , 241 C o m p r e h e n s i o n test o f , 6, 9, 4 7 , 5 2 - 5 3 , 55, 216 crystallized intelligence a n d , 9, 4 7 , 5 1 - 5 3 , 2 1 6 - 1 7 , 241 fluid intelligence a n d , 8—9, 4 7 , 52, 5 5 - 5 6 , 5 9 , 2 1 7 , 241 Full Scale I Q a n d , 9 , 4 7 g e n e r a t i o n a l c h a n g e in, 46—47, 5 1 - 5 3 , 55 g l o a d i n g s in, 2 1 6 - 1 8 , 2 4 0 - 4 1 I n f o r m a t i o n test o f , 6, 9, 4 7 , 5 3 - 5 4 , 216

INDEX

304

W e c h s l e r Intelligence Scale f o r C h i l dren ( W I S C ) ( c o n t i n u e d ) O b j e c t A s s e m b l y test o f , 6, 8, 4 7 , 56 p e r f o r m a n c e I Q and, 9 , 46—47, 4 9 - 5 1 , 241 Picture A r r a n g e m e n t test o f , 6, 8, 4 7 , 56 Picture C o m p l e t i o n test o f , 6, 8, 4 7 , 56 re-norming of, 44 Similarities rest o f , 6, 9, 4 7 , 5 1 - 5 2 , 55, 216 V e r b a l I Q and, 9 , 4 7 , 5 1 - 5 3 , 9 8 - 9 9 , 2 1 4 , 241 V o c a b u l a r y test o f , 6, 7, 9, 4 7 , 53, 216 W e c h s l e r Preschool and P r i m a r y Scale of Intelligence, 125 W e i k a r t , D a v i d , 123 Weinberg, R. A., 223-24, 225 W e s t , pure k n o w l e d g e valued by, 4 - 5 , 169 W e s t A f r i c a n s , 176 W e s t Indians, 109-1 1, 225

W e s t i n g h o u s e Science Fair, 154 W h a t W o r k s C l e a r i n g h o u s e , 73—74, 191 w h i t e s , see E u r o p e a n A m e r i c a n s w h o l e - s c h o o l interventions, 6 9 - 7 1 , 7 3 , 132, 1 3 4 - 3 6 , 149, 195 Willerman, L., 230 Williams, W e n d y , 40, 49 W I S C , see W e c h s l e r Intelligence Scale f o r C h i l d r e n W i t t y , P. A., 229 W o o d c o c k - J o h n s o n tests, 64 w o r k i n g class: definition of, 79 e c o n o m i c status o f , in U.S. vs. E u r o p e and Japan, 79 parenting practices o f , 8 8 - 8 9 w o r k i n g m e m o r y , 7 , 9 , 4 9 , 50, 186 Y e h o s h u a ben G a m l a , 171 Y p s i l a n t i , M i c h . , 123 Z e n o , 1 66 Z w e i g , Stefan, 1 7 9 - 8 0

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