T
he private dialogue about race in America is far different from the
public one, and we are not referring just to discussions among white
rednecks. Our impression is that the private attitudes of white elites
toward blacks is strained far beyond any public acknowledgment, that
hostility is not uncommon and that a key part of the strain is a growing
suspicion that fundamental racial differences are implicated in the
social and economic gap that continues to separate blacks and whites,
especially alleged genetic differences in intelligence.
We say "our impression" because we have been in a unique position to
gather impressions. Since the beginning of 1990, we have been writing a
book about differences in intellectual capacity among people and groups
and what those differences mean for America's future. As authors do, we
have gotten into numberless conversations that begin, "What are you
working on now?" Our interlocutors have included scholars at the
top-ranked universities and think tanks, journalists, high public
officials, lawyers, financiers and corporate executives. In the
aggregate, they have split about evenly between left and right of the
political center.
With rare exceptions, these people have shared one thing besides their
success. As soon as the subject turned to the question of I.Q., they
focused on whether there was any genetic race differences in
intelligence. And they tended to be scared stiff about the answer. This
experience has led us to be scared as well, about the consequences of
ignorance. We have been asked whether the question of racial genetic
differences in intelligence should even be raised in polite society. We
believe there's no alternative. A taboo issue, filled with potential for
hurt and anger, lurks just beneath the surface of American life. It is
essential that people begin to talk about this in the open. Because
raising this question at all provokes a host of fears, it is worth
stating at the outset a clear conclusion of our research: the
fascination with race, I.Q. and genes is misbegotten. There are all
sorts of things to be worried about regarding intelligence and American
life, and even regarding intelligence and ethnicity. But genetics isn't
one of them.
First, the evidence, beginning with this furiously denied fact:
intelligence is a useful construct. Among the experts, it is by now
beyond much technical dispute that there is such a thing as a general
factor of cognitive ability on which human beings differ and that this
general factor is measured reasonably well by a variety of standardized
tests, best of all by I.Q. tests designed for that purpose. These points
are no longer the topic of much new work in the technical journals
because most of the questions about them have been answered.
Intelligence as measured by I.Q. tests is predictive of many
educational, economic and social outcomes. In America today, you are
much better off knowing a child's I.Q. score than her parents' income or
education if you want to predict whether she will drop out of high
school, for example. If you are an employer trying to predict an
applicant's job productivity and are given a choice of just one item of
information, you are usually better off asking for an I.Q. score than a
resume, college transcript, letter of recommendation or even a job
interview. These statements hold true for whites, blacks, Asians and
Latinos alike.
This is not to say that I.Q. is destiny--in each of these instances,
I.Q. is merely a better predictor than the alternatives, not even close
to a perfect one. But it should be stated that the pariah status of
intelligence as a construct and I.Q. as its measure for the past three
decades has been a function of political fashion, notscience.
Ethnic differences in measured cognitive ability have been found since
intelligence tests were invent- ed. The battle over the meaning of these
differences is largely responsible for today's controversy over
intelligence testing itself. The first thing to remember is that the
differences among individuals are far greater than the differences among
groups. If all the ethnic differences in intelligence evaporated
overnight, most of the intellectual variation in America would endure.
The remaining inequality would still strain the political process,
because differences in cognitive ability are problematic even in
ethnically homogeneous societies.
Even using the word "race" is problematic, which is why we use the word
ethnicity as well as race in this article. What does it mean to be
"black" in America, in racial terms, when the word black (or African
American) can be used for people whose ancestry is more European than
African? How are we to classify a person whose parents hail from Panama
but whose ancestry is predominantly African? Is he Latino? Black? The
rule we follow here is a simple one: to classify people according to the
way they classify themselves.
We might start with a common question in America these days: Do Asians
have higher I.Q.s than whites? The answer is probably yes, if Asian
refers to the Japanese and Chinese (and perhaps also Koreans), whom we
will refer to here as East Asians. How much higher is still unclear. The
best tests of this have involved identical I.Q. tests given to
populations that are comparable except for race. In one test, samples of
American, British and Japanese students aged 13 to 15 were given a test
of abstract reasoning and spatial relations. The U.S. and U.K. samples
had scores within a point of the standardized mean of 100 on both the
abstract and spatial relations parts of the test; the Japanese scored
104.5 on the test for abstract reasoning and 114 on the test for spatial
relations--a large difference, amounting to a gap similar to the one
found by another leading researcher for Asians in America. In a second
set of studies, 9-year-olds in Japan, Hong Kong and Britain, drawn from
comparable socioeconomic populations, were administered the Ravens
Standard Progressive Matrices. The children from Hong Kong averaged 113;
from Japan, 110; and from Britain, 100.
Not everyone accepts that the East Asian-white difference exists.
Another set of studies gave a battery of mental tests to elementary
school children in Japan, Taiwan and Minneapolis, Minnesota. The key
difference between this study and the other two was that the children
were matched carefully on many socioeconomic and demographic variables.
No significant difference in overall I.Q. was found, and the authors
concluded that "this study offers no support for the argument that there
are differences in the general cognitive functioning of Chinese,
Japanese and American children."
Where does this leave us? The parties in the debate are often confident,
and present in their articles are many flat statements that an overall
East Asian-white I.Q. difference does, or does not, exist. In our
judgment, the balance of the evidence supports the notion that the
overall East Asian mean is higher than the white mean. Three I.Q. points
most resembles a consensus, tentative though it still is. East Asians
have a greater advantage in a particular kind of nonverbal intelligence.
The issues become far more fraught, however, in determining the answer
to the question: Do African Americans score differently from whites on
standardized tests of cognitive ability? If the samples are chosen to be
representative of the American population, the answer has been yes for
every known test of cognitive ability that meets basic psychometric
standards. The answer is also yes for almost all studies in which the
black and white samples are matched on some special
characteristics--juvenile delinquents, for example, or graduate
students- -but there are exceptions. How large is the black-white
difference? The usual answer is what statisticians call one standard
deviation. In discussing I.Q. tests, for example, the black mean is
commonly given as 85, the white mean as 100 and the standard deviation
as fifteen points. But the differences observed in any given study
seldom conform exactly to one standard deviation. In 156 American
studies conducted during this century that have reported the I.Q. means
of a black sample and a white sample, and that meet basic requirements
of interpretability, the mean black-white difference is 1.1 standard
deviations, or about sixteen I.Q. points.
More rigorous selection criteria do not diminish the size of the gap.
For example, with tests given outside the South only after 1960, when
people were increasingly sensitized to racial issues, the number of
studies is reduced to twenty-four, but the mean difference is still 1.1
standard deviations. The National Longitudinal Survey of Youth (NLSY)
administered an I.Q. test in 1980 to by far the largest and most
carefully selected national sample (6,502 whites, 3,022 blacks) and
found a difference of 1.2 standard deviations.
Evidence from the sat, the act and the National Assessment of
Educational Progress gives reason to think that the black-white I.Q.
difference has shrunk by perhaps three I.Q. points in the last twenty
years. Almost all the improvement came in the low end, however, progress
has stalled for several years and the most direct evidence, from I.Q.
tests of the next generation in the NLSY, points to a widening black-
white gap rather than a shrinking one.
It is important to understand that even a difference of 1.2 standard
deviations means considerable overlap in the cognitive ability
distribution for blacks and whites, as shown for the NLSY population in
the figure on page 28. For any equal number of blacks and whites, a
large proportion have I.Q.s that can be matched up. For that matter,
millions of blacks have higher I.Q.s than the average white. Tens of
thousands have I.Q.s that put them in the top few percentiles of the
white distribution. It should be no surprise to see (as everyone does
every day) African Americans functioning at high levels in every
intellectually challenging field. This is the distribution to keep in
mind whenever thinking about individuals.
But an additional complication must be taken into account: in the United
States, there are about six whites for every black. This means that the
I.Q. overlap of the two populations as they actually exist in the United
States looks very different from the overlap in the figure on page 28.
The figure above presents the same data from the NLSY when the
distributions are shown in proportion to the actual population of young
people in the NLSY. This figure shows why a black- white difference can
be problematic to society as a whole. At the lower end of the I.Q.
range, there are about equal numbers of blacks and whites. But
throughout the upper half of the range, the disproportions between the
number of whites and blacks at any given I.Q. level are huge. To the
extent that the difference represents an authentic difference in
cognitive functioning, the social consequences are huge as well. But is
the difference authentic? Is it, for example, attributable to cultural
bias or other artifacts of the test? There are several ways of assessing
this. We'll go through them one by one.
External evidence of bias. Tests are used to predict things--most
commonly, to predict performance in school or on the job. The ability of
a test to predict is known as its validity. A test with high validity
predicts accurately; a test with poor validity makes many mistakes. Now
suppose that a test's validity differs for the members of two groups. To
use a concrete example: the sat is used as a tool in college admissions
because it has a certain validity in predicting college performance. If
the sat is biased against blacks, it will underpredict their college
performance. If tests were biased in this way, blacks as a group would
do better in college than the admissions office expected based just on
their sats. It would be as if the test underestimated the "true" sat
score of the blacks, so the natural remedy for this would be to
compensate the black applicants by, for example, adding the appropriate
number of points to their scores. Predictive bias can work in another
way, as when the test is simply less reliable- -that is, less
accurate--for blacks than for whites. Suppose a test used to select
police sergeants is more accurate in predicting the performance of white
candidates who become sergeants than in predicting the performance of
black sergeants. It doesn't underpredict for blacks, but rather fails to
predict at all (or predicts less accurately). In these cases, the
natural remedy would be to give less weight to the test scores of blacks
than to those of whites.
The key concept for both types of bias is the same: a test biased
against blacks does not predict black performance in the real world in
the same way that it predicts white performance in the real world. The
evidence of bias is external in the sense that it shows up in differing
validities for blacks and whites. External evidence of bias has been
sought in hundreds of studies. It has been evaluated relative to
performance in elementary school, in the university, in the military, in
unskilled and skilled jobs, in the professions. Overwhelmingly, the
evidence is that the standardized tests used to help make school and job
decisions do not underpredict black performance. Nor does the expert
community find any other systematic difference in the predictive
accuracy of tests for blacks and whites. Internal evidence of bias. The
most common charges of cultural bias involve the putative cultural
loading of items in a test. Here is an sat analogy item that has become
famous as an example of cultural bias: RUNNER: MARATHON (A) envoy:
embassy (B) martyr: massacre (C) oarsman: regatta (D) referee:
tournament (E) horse: stable The answer is "oarsman: regatta"--fairly
easy if you know what both a marathon and a regatta are, a matter of
guesswork otherwise. How would a black youngster from the inner city
ever have heard of a regatta? Many view such items as proof that the
tests must be biased against people from disadvantaged backgrounds.
"Clearly, " writes a critic of testing, citing this example, "this item
does not measure students' `aptitude' or logical reasoning ability, but
knowledge of upper-middle-class recreational activity." In the language
of psychometrics, this is called internal evidence of bias. The
hypothesis of bias again lends itself to direct examination. In effect,
the sat critic is saying that culturally loaded items are producing at
least some of the black-white difference. Get rid of such items, and the
gap will narrow. Is he correct? When we look at the results for items
that have answers such as "oarsman: regatta" and the results for items
that seem to be empty of any cultural information (repeating a sequence
of numbers, for example), are there any differences? The technical
literature is again clear. In study after study of the leading tests,
the idea that the black-white difference is caused by questions with
cultural content has been contradicted by the facts. Items that the
average white test-taker finds easy relative to other items, the average
black test-taker does, too; the same is true for items that the average
white and black find difficult. Inasmuch as whites and blacks have
different overall scores on the average, it follows that a smaller
proportion of blacks get right answers for either easy or hard items,
but the order of difficulty is virtually the same in each racial group.
How can this be? The explanation is complicated and goes deep into the
reasons why a test item is "good" or "bad" in measuring intelligence.
Here, we restrict ourselves to the conclusion: The black-white
difference is generally wider on items that appear to be culturally
neutral than on items that appear to be culturally loaded. We italicize
this point because it is so well established empirically yet comes as
such a surprise to most people who are new to this topic.
Motivation to try. Suppose the nature of cultural bias does not lie in
predictive validity or in the content of the items but in what might be
called "test willingness." A typical black youngster, it is
hypothesized, comes to such tests with a mindset different from the
white subject's. He is less attuned to testing situations (from one
point of view), or less inclined to put up with such nonsense (from
another). Perhaps he just doesn't give a damn, since he has no hopes of
going to college or otherwise benefiting from a good test score. Perhaps
he figures that the test is biased against him anyway, so what's the
point. Perhaps he consciously refuses to put forth his best effort
because of the peer pressure against "acting white" in some inner-city
schools.
The studies that have attempted to measure motivation in such situations
generally have found that blacks are at least as motivated as whites.
But these are not wholly convincing, for why shouldn't the measures of
motivation be just as inaccurate as the measures of cognitive ability
are alleged to be? Analysis of internal characteristics of the tests
once again offers the best leverage in examining this broad hypothesis.
Here, we will offer just one example involving the "digit span" subtest,
part of the widely used Wechsler intelligence tests. It has two forms:
forward digit span, in which the subject tries to repeat a sequence of
numbers in the order read to him, and backward digit span, in which the
subject tries to repeat the sequence of numbers backward. The test is
simple, uses numbers familiar to everyone and calls on no cultural
information besides numbers. The digit span is informative regarding
test motivation not just because of the low cultural loading of the
items but because the backward form is a far better measure of "g," the
psychometrician's shorthand for the general intelligence factor that
I.Q. tests try to measure. The reason that the backward form is a better
measure of g is that reversing the numbers is mentally more demanding
than repeating them in the heard order, as you can determine for
yourself by a little self-testing.
The two parts of the subtest have identical content. They occur at the
same time during the test. Each subject does both. But in most studies
the black-white difference is about twice as great on backward digits as
on forward digits. The question then arises: How can lack of motivation
(or test willingness) explain the difference in performance on the two
parts of the same subtest?
This still leaves another obvious question: Are the differences in
overall black and white test scores attributable to differences in
socioeconomic status? This question has two different answers depending
on how the question is understood, and confusion is rampant. There are
two essential answers and two associated rationales.
First version: If you extract the effects of socioeconomic class, what
happens to the magnitude of the black-white difference? Blacks are
disproportionately in the lower socioeconomic classes, and class is
known to be associated with I.Q. Therefore, many people suggest, part of
what appears to be an ethnic difference in I.Q. scores is actually a
socioeconomic difference. The answer to this version of the question is
that the size of the gap shrinks when socioeconomic status is
statistically extracted. The NLSY gives a result typical of such
analyses. The black-white difference in the NLSY is 1.2. In a regression
equation in which both race and socioeconomic background are entered,
the difference between whites and blacks shrinks to less than .8
standard deviation. Socioeconomic status explains 37 percent of the
original black-white difference. This relationship is in line with the
results from many other studies.
The difficulty comes in interpreting what it means to "control" for
socioeconomic status. Matching the status of the groups is usually
justified on the grounds that the scores people earn are caused to some
extent by their socioeconomic status, so if we want to see the "real" or
"authentic" difference between them, the contribution of status must be
excluded. The trouble is that socioeconomic status is also a result of
intelligence, as people of high and low cognitive ability move to high
and low places in the class structure. The reason parents have high or
low socioeconomic status is in part a function of their intelligence,
and their intelligence also affects the I.Q. of the children via both
genes and environment.
Because of these relationships, "controlling" for socioeconomic status
in racial comparisons is guaranteed to reduce I.Q. differences in the
same way that choosing black and white samples from a school for the
intellectually gifted is guaranteed to reduce I.Q. differences (assuming
race-blind admissions standards). These complications aside, a
reasonable rule of thumb is that controlling for socioeconomic status
reduces the overall black-white difference by about one-third.
Second version: As blacks move up the socioeconomic ladder, do the
differences with whites of similar socioeconomic status diminish? The
first version of the SES/I.Q. question referred to the overall score of
a population of blacks and whites. The second version concentrates on
the black-white difference within socioeconomic classes. The rationale
goes like this: blacks score lower on average because they are
socioeconomically at a disadvantage. This disadvantage should most
seriously handicap children in the lower socioeconomic classes, who
suffer from greater barriers to education and job advancement than do
children in the middle and upper classes. As blacks advance up the
socioeconomic ladder, their children, less exposed to these barriers,
will do better and, by extension, close the gap with white children of
their class.
This expectation is not borne out by the data. A good way to illustrate
this is to use an index of parental ses based on their education, income
and occupation and to match it against the mean I.Q. score, as shown in
the figure on page 32. I.Q. scores increase with economic status for
both races. But as the figure shows, the magnitude of the black-white
difference in standard deviations does not decrease. Indeed, it gets
larger as people move up from the very bottom of the socioeconomic
ladder. The pattern shown in the figure is consistent with many other
major studies, except that the gap flattens out. In other studies, the
gap has continued to increase throughout the range of socioeconomic
status.
This brings us to the flashpoint of intelligence as a public topic: the
question of genetic differences between the races. Expert opinion, when
it is expressed at all, diverges widely. In the 1980s Mark Snyderman, a
psychologist, and Stanley Rothman, a political scientist, sent a
questionnaire to a broad sample of 1,020 scholars, mostly academicians,
whose specialties give them reason to be knowledgeable about I.Q. Among
other questions, they asked, "Which of the following best characterizes
your opinion of the heritability of the black-white difference in I.Q.?"
The answers were divided as follows: The difference is entirely due to
environmental variation: 15 percent. The difference is entirely due to
genetic variation: 1 percent. The difference is a product of both
genetic and environmental variation: 45 percent. The data are
insufficient to support any reasonable opinion: 24 percent. No response:
14 percent.
This pretty well sums up the professional judgment on the matter. But it
doesn't explain anything about the environment/genetic debate as it has
played out in the profession and in the general public. And the
question, of course, is fascinating. So what could help us understand
the connection between heritability and group differences? A good place
to start is by correcting a common confusion about the role of genes in
individuals and in groups.
Most scholars accept that I.Q. in the human species as a whole is
substantially heritable, somewhere between 40 percent and 80 percent,
meaning that much of the observed variation in I.Q. is genetic. And yet
this information tells us nothing for sure about the origin of the
differences between groups of humans in measured intelligence. This
point is so basic, and so misunderstood, that it deserves emphasis: that
a trait is genetically transmitted in a population does not mean that
group differences in that trait are also genetic in origin. Anyone who
doubts this assertion may take two handfuls of genetically identical
seed corn and plant one handful in Iowa, the other in the Mojave Desert,
and let nature (i.e., the environment) take its course. The seeds will g
row in Iowa, not in the Mojave, and the result will have nothing to do
with genetic differences.
The environment for American blacks has been closer to the Mojave and
the environment for American whites has been closer to Iowa. We may
apply this general observation to the available data and see where the
results lead. Suppose that all the observed ethnic differences in tested
intelligence originate in some mysterious environmental
differences--mysterious, because we know from material already presented
that socioeconomic factors cannot be much of the explanation. We further
stipulate that one standard deviation (fifteen I.Q. points) separates
American blacks and whites and that one-fifth of a standard deviation
(three I.Q. points) separates East Asians and whites. Finally, we assume
that I.Q. is 60 percent heritable (a middle-ground estimate). Given
these parameters, how different would the environments for the three
groups have to be in order to explain the observed difference in these
scores?
The observed ethnic differences in I.Q. could be explained solely by the
environment if the mean environment of whites is 1.58 standard
deviations better than the mean environment of blacks and .32 standard
deviation worse than the mean environment for East Asians, when
environments are measured along the continuum of their capacity to
nurture intelligence. Let's state these conclusions in percentile terms:
the average environment of blacks would have to be at the sixth
percentile of the distribution of environments among whites and the
average environment of East Asians would have to be at the sixty-third
percentile of environments among whites for the racial differences to be
entirely environmental.
Environmental differences of this magnitude and pattern are wildly out
of line with all objective measures of the differences in black, Asian
and white environments. Recall further that the black-white difference
is smallest at the lowest socioeconomic levels. Why, if the black-white
difference is entirely environmental, should the advantage of the
"white" environment compared to the "black" be greater among the
better-off and better- educated blacks and whites? We have not been able
to think of a plausible reason. Can you? An appeal to the effects of
racism to explain ethnic differences also requires explaining why
environments poisoned by discrimination and racism for some other
groups--against the Chinese or the Jews in some regions of America for
example--have left them with higher scores than the national average.
However discomfiting it may be to consider it, there are reasons to
suspect genetic considerations are involved. The evidence is
circumstantial, but provocative. For example, ethnicities differ not
just in average scores but in the profile of intellectual capacities. A
full-scale I.Q. score is the aggregate of many subtests. There are
thirteen of them in the Wechsler Intelligence Scale for Children, for
example. The most basic division of the subtests is into a verbal I.Q.
and a performance I.Q. In white samples the verbal and performance I.Q.
subscores tend to have about the same mean, because I.Q. tests have been
standardized on predominantly white populations. But individuals can
have imbalances between these two I.Q.s. People with high verbal
abilities are likely to do well with words and logic. In school they
excel in history and literature; in choosing a career to draw on those
talents, they tend to choose law or journalism or advertising or
politics. In contrast, people with high performance I.Q.s--or, using a
more descriptive phrase, "visuospatial abilities"--are likely to do well
in the physical and biological sciences, mathematics, engineering or
other subjects that demand mental manipulation in the three physical
dimensions or the more numerous dimensions of mathematics.
East Asians living overseas score about the same or slightly lower than
whites on verbal I.Q. and substantially higher on visuospatial I.Q. Even
in the rare studies that have found overall Japanese or Chinese I.Q.s no
higher than white I.Q.s, the discrepancy between verbal and visuospatial
I.Q. persists. For Japanese living in Asia, a 1987 review of the
literature demonstrated without much question that the
verbal-visuospatial difference persists even in examinations that have
been thoroughly adapted to the Japanese language and, indeed, in tests
developed by the Japanese themselves. A study of a small sample of
Korean infants adopted into white families in Belgium found the familiar
elevated visuospatial scores. This finding has an echo in the United
States, where Asian American students abound in science subjects, in
engineering and in medical schools, but are scarce in law schools and
graduate programs in the humanities and social sciences. Is this just a
matter of parental pressures or of Asian immigrants uncomfortable with
English? The same pattern of subtest scores is found in Inuits and
American Indians (both of Asian origin) and in fully assimilated second-
and third-generation Asian Americans. Any simple socioeconomic, cultural
or linguistic explanation is out of the question, given the diversity of
living conditions, native languages, educational systems and cultural
practices experienced by these groups and by East Asians living in Asia.
Their common genetic history cannot plausibly be dismissed as irrelev
ant.
Turning now to blacks and whites (using these terms to refer exclusively
to Americans), ability profiles also have been important in
understanding the nature, and possible genetic component, of group
differences. The argument has been developing around what is known as
Spearman' s hypothesis. This hypothesis says that if the black-white
difference on test scores reflects a real underlying difference in
general mental ability (g), then the size of the black-white difference
will be related to the degree to which the test is saturated with g. In
other words, the better a test measures g, the larger the black-white
difference will be.
By now, Spearman's hypothesis has been borne out in fourteen major
studies, and no appropriate data set has yet been found that contradicts
Spearman's hypothesis. It should be noted that not all group differences
behave similarly. For example, deaf children often get lower test scores
than hearing children, but the size of the difference is not correlated
positively with the test's loading on g. The phenomenon seems peculiarly
concentrated in comparisons of ethnic groups. How does this bear on the
genetic explanation of ethnic differences? In plain though somewhat
imprecise language: the broadest conception of intelligence is embodied
in g. At the same time, g typically has the highest heritability (higher
than the other factors measured by I.Q. tests). As mental measurement
focuses most specifically and reliably on g, the observed black-white
mean difference in cognitive ability gets larger. This does not in
itself demand a genetic explanation of the ethnic difference but, by
asserting that "the better the test, the greater the ethnic difference,"
Spearman's hypothesis undercuts many of the environmental explanations
of the difference that rely on the proposition (again, simplifying) that
the apparent black-white difference is the result of bad tests, not good
ones.
There are, of course, many arguments against such a genetic explanation.
Many studies have shown that the disadvantaged environment of some
blacks has depressed their test scores. In one study, in black families
in rural Georgia, the elder sibling typically had a lower I.Q. than the
younger. The larger the age difference is between the siblings, the
larger is the difference in I.Q. The implication is that something in
the rural Georgia environment was depressing the scores of black
children as they grew older. In neither the white families of Georgia,
nor white or black families in Berkeley, California, were there
comparable signs of a depressive effect of the environment.
Another approach is to say that tests are artifacts of a culture, and a
culture may not diffuse equally into every household and community. In a
heterogeneous society, subcultures vary in ways that inevitably affect
scores on I.Q. tests. Fewer books in the home mean less exposure to the
material that a vocabulary subtest measures; the varying ways of
socializing children may influence whether a child acquires the skills,
or a desire for the skills, that tests test; the "common knowledge" that
tests supposedly draw on may not be common in certain households and
neighborhoods. So far, this sounds like a standard argument about
cultural bias, and yet it accepts the generalizations that we discussed
earlier about internal evidence of bias. The supporters of this argument
are not claiming that less exposure to books means that blacks score
lower on vocabulary questions but do as well as whites on culture- free
items. Rather, the effects of culture are more diffuse.
Furthermore, strong correlations between home or community life and I.Q.
scores are readily found. In a study of 180 Latino and 180 non-Latino
white elementary school children in Riverside, California, the
researcher examined eight sociocultural variables: (1) mother' s
participation in formal organizations, (2) living in a segregated
neighborhood, (3) home language level, (4) socioeconomic status based on
occupation and education of head of household, (5) urbanization, (6)
mother's achievement values, (7) home ownership, and (8) intact
biological family. She then showed that once these sociocultural
variables were taken into account, the remaining group and I.Q.
differences among the children fell to near zero.
The problem with this procedure lies in determining what, in fact, these
eight variables control for: cultural diffusion, or genetic sources of
variation in intelligence as ordinarily understood? By so drastically
extending the usual match for socioeconomic status, the possibility is
that such studies demonstrate only that parents matched on I.Q. will
produce children with similar I.Q.s--not a startling finding. Also, the
data used for such studies continue to show the distinctive racial
patterns in the subtests. Why should cultural diffusion manifest itself
by differences in backward and forward digit span or in completely
nonverbal items? If the role of European white cultural diffusion is so
important in affecting black I.Q. scores, why is it so unimportant in
affecting Asian I.Q. scores?
There are other arguments related to cultural bias. In the American
context, Wade Boykin is one of the most prominent academic advocates of
a distinctive black culture, arguing that nine interrelated dimensions
put blacks at odds with the prevailing Eurocentric model. Among them are
spirituality (blacks approach life as "essentially vitalistic rather
than mechanistic, with the conviction that nonmaterial forces influence
people's everyday lives"); a belief in the harmony between humankind and
nature; an emphasis on the importance of movement, rhythm, music and
dance, "which are taken as central to psychological health" ; personal
styles that he characterizes as "verve" (high levels of stimulation and
energy) and "affect" (emphasis on emotions and expressiveness); and
"social time perspective," which he defines as "an orientation in which
time is treated as passing through a social space rather than a material
one." Such analyses purport to explain how large black- white
differences in test scores could coexist with equal predictive validity
of the test for such things as academic and job performance and yet
still not be based on differences in "intelligence," broadly defined,
let alone genetic differences.
John Ogbu, a Berkeley anthropologist, has proposed a more specific
version of this argument. He suggests that we look at the history of
various minority groups to understand the sources of differing levels of
intellectual attainment in America. He distinguishes three types of
minorities: "autonomous minorities" such as the Amish, Jews and Mormons,
who, while they may be victims of discrimination, are still within the
cultural mainstream; "immigrant minorities," such as the Chinese,
Filipinos, Japanese and Koreans within the United States, who moved
voluntarily to their new societies and, while they may begin in menial
jobs, compare themselves favorably with their peers back in the home
country; and, finally, "castelike minorities, " such as black Americans,
who were involuntary immigrants or otherwise are consigned from birth to
a distinctively lower place on the social ladder. Ogbu argues that the
differences in test scores are an outcome of this historical
distinction, pointing to a number of castes around the world--the
untouchables in India, the Buraku in Japan and Oriental Jews in
Israel--that have exhibited comparable problems in educational
achievement despite being of the same racial group as the majority.
Indirect support for the proposition that the observed black-white
difference could be the result of environmental factors is provided by
the worldwide phenomenon of rising test scores. We call it "the Flynn
effect" because of psychologist James Flynn's pivotal role in focusing
attention on it, but the phenomenon itself was identified in the 1930s
when testers began to notice that I.Q. scores often rose with every
successive year after a test was first standardized. For example, when
the Stanford-Binet I.Q. was restandardized in the mid- 1930s, it was
observed that individuals earned lower I.Q.s on the new tests than they
got on the Stanford-Binet that had been standardized in the mid-1910s;
in other words, getting a score of 100 (the population average) was ha
rder to do on the later test. This meant that the average person could
answer more items on the old test than on the new test. Most of the
change has been concentrated in the nonverbal portions of the tests.
The tendency for I.Q. scores to drift upward as a function of years
since standardization has now been substantiated in many countries and
on many I.Q. tests besides the Stanford-Binet. In some countries, the
upward drift since World War II has been as much as a point per year for
some spans of years. The national averages have in fact changed by
amounts that are comparable to the fifteen or so I.Q. points separating
whites and blacks in America. To put it another way, on the average,
whites today may differ in I.Q. from whites, say, two generations ago as
much as whites today differ from blacks today. Given their size and
speed, the shifts in time necessarily have been due more to changes in
the environment than to changes in the genes. The question then arises:
Couldn't the mean of blacks move fifteen points as well through
environmental changes? There seems no reason why not--but also no reason
to believe that white and Asian means can be made to stand still while
the Flynn effect works its magic.
As of 1994, then, we can say nothing for certain about the relative
roles that genetics and environment play in the formation of the black-
white difference in I.Q. All the evidence remains indirect. The
heritability of individual differences in I.Q. does not necessarily mean
that ethnic differences are also heritable. But those who think that
ethnic differences are readily explained by environmental differences
haven't been toughminded enough about their own argument. At this
complex intersection of complex factors, the easy answers are
unsatisfactory ones.
Given the weight of the many circumstantial patterns, it seems
improbable to us--though possible--that genes have no role whatsoever.
What might the mix of genetic and environmental influences be? We are
resolutely agnostic on that.
Here is what we hope will be our contribution to the discussion. We put
it in italics; if we could, we would put it in neon lights: The answer
doesn't much matter. Whether the black-white difference in test scores
is produced by genes or the environment has no bearing on any of the
reasons why the black-white difference is worth worrying about. If
tomorrow we knew beyond a shadow of a doubt what role, if any, were
played by genes, the news would be neither good if ethnic differences
were predominantly environmental, nor awful if they were predominantly
genetic. The first reason for this assertion is that what matters is not
whether differences are environmental or genetic, but how hard they are
to change. Many people have a fuzzy impression that if cognitive ability
has been depressed by a disadvantaged environment, it is easily
remedied. Give the small child a more stimulating environment, give the
older child a better education, it is thought, and the environmental
deficit can be made up. This impression is wrong. The environment
unquestionably has an impact on cognitive ability, but a record of
interventions going back more than fifty years has demonstrated how
difficult it is to manipulate the environment so that cognitive
functioning is improved. The billions of dollars spent annually on
compensatory education under Title I of the Elementary and Secondary
Education Act have had such a dismal evaluation record that improving
general cognitive functioning is no longer even a goal. Preschool
education fares little better. Despite extravagant claims that
periodically get their fifteen minutes of fame, preschool education,
including not just ordinary Head Start but much more intensive programs
such as Perry Preschool, raises I.Q. scores by a few points on the exit
test, and even those small gains quickly fade. Preschool programs may be
good for children in other ways, but they do not have important effects
on intelligence. If larger effects are possible, it is only through
truly heroic efforts, putting children into full-time, year- round,
highly enriched day care from within a few months of birth and keeping
them there for the first five years of life--and even those effects,
claimed by the Milwaukee Program and the Abecedarian Project, are
subject to widespread skepticism among scholars.
In short: if it were proved tomorrow that ethnic differences in test
scores were entirely environmental, there would be no reason to
celebrate. That knowledge would not suggest a single educational,
preschool, day care or prenatal program that is not already being tried,
and would give no reason to believe that tomorrow's effects from such
programs will be any more encouraging than those observed to date.
Radically improved knowledge about child development and intelligence is
required, not just better implementation of what is already known. No
breakthroughs are in sight.
The second reason that the concern about genes is overblown is the
mistaken idea that genes mean there is nothing to be done. On the
contrary, the distributions of genetic traits in a population can change
over time, because people who die are not replaced one- for-one by
babies with matched dna. Just because there might be a genetic
difference among groups in this generation does not mean that it cannot
shrink. Nor, for that matter, does genetic equality in this generation
mean that genetic differences might not arise within a matter of
decades. It depends on which women in which group have how many babies
at what ages. More broadly, genetic causes do not leave us helpless.
Myops see fine with glasses and many bald men look as if they have hair,
however closely myopia and baldness are tied to genes. Check out visual
aids and gimmicks on any Macintosh computer to see how technology can
compensate for innumeracy and illiteracy.
Now comes the third reason that the concern about genes needs
rethinking. It is to us the most compelling: there is no rational reason
why any encounter between individuals should be affected in any way by
the knowledge that a group difference is genetic instead of
environmental. Suppose that the news tomorrow morning is that the
black-white difference in cognitive test scores is rooted in genetic
differences. Suppose further that tomorrow afternoon, you-- let us say
you are white--encounter a random African American. Try to think of any
way in which anything has changed that should affect your evaluation of
or response to that individual and you will soon arrive at a truth that
ought to be assimilated by everyone: nothing has changed. That an
individual is a member of a group with a certain genetically based mean
and distribution in any characteristic, whether it be height,
intelligence, predisposition to schizophrenia or eye color has no effect
on that reality of that individual. A five-foot man with six-foot p
arents is still five feet tall, no matter how much height is determined
by genes. An African American with an I.Q. of 130 still has an I.Q. of
130, no matter what the black mean may be or to what extent I.Q. is
determined by genes. Maybe for some whites, behavior toward black
individuals would change if it were known that certain ethnic
differences were genetic--but not for any good reason.
We have been too idealistic, one may respond. In the real world, people
treat individuals according to their membership in a group. Consider the
young black male trying to catch a taxi. It makes no difference how
honest he is; many taxi drivers will refuse to pick him up because young
black males disproportionately account for taxi robberies. Similarly,
some people fear that talking about group differences in I.Q. will
encourage employers to use ethnicity as an inexpensive screen if they
can get away with it, not bothering to consider black candidates.
These are authentic problems that need to be dealt with. But it puzzles
us to hear them raised as a response to the question, "What difference
does it make if genes are involved?" Two separate issues are being
conflated: the reality of a difference versus its source. An employer
has no more incentive to discriminate by ethnicity if he knows that a
difference in ability is genetic than if he knows it is "only"
environmental. To return to an earlier point, the key issue is how
intractable the difference is. By the time someone is applying for a
job, his cognitive functioning can be tweaked only at the margins, if at
all, regardless of the original comparative roles of genes and
environment in producing that level of cognitive functioning. The
existence of a group difference may make a difference in the behavior of
individuals toward other individuals, with implications that may well
spill over into policy, but the source of the difference is irrelevant
to the behavior.
In The Bell Curve, we make all of the above points, document them fully
and are prepared to defend them against all comers. We argue that the
best and indeed only answer to the problem of group differences is an
energetic and uncompromising recommitment to individualism. To judge
someone except on his or her own merits was historically thought to be
un-American, and we urge that it become so again.
But as we worked on the discussion in the book, we also became aware
that ratiocination is not a sufficient response. Many people
instinctively believe that genetically caused group differences in
intelligence must be psychologically destructive in a way that
environmentally caused differences are not. In a way, our informal
survey of elites during the writing of the book confirmed this. No
matter what we said, we found that people walked away muttering that it
does make a difference if genes are involved. But we nonetheless are not
persuaded. It seems to us that, on the contrary, human beings have it in
them to live comfortably with all kinds of differences, group and
individual alike.
We did not put those thoughts into the book. Early on, we decided that
the passages on ethnic differences in intelligence had to be inflexibly
pinned to data. Speculations were out, and even provocative turns of
phrase had to be guarded against. The thoughts we are about to express
are decidedly speculative, and hence did not become part of our book.
But if you will treat them accordingly, we think they form the basis of
a conversation worth beginning, and we will open it here.
As one looks around the world at the huge variety of ethnic groups that
have high opinions of themselves, for example, one is struck by how easy
it is for each of these clans, as we will call them, to conclude that it
has the best combination of genes and culture in the world. In each
clan's eyes, its members are blessed to have been born who they
are--Arab, Chinese, Jew, Welsh, Russian, Spanish, Zulu, Scots,
Hungarian. The list could go on indefinitely, breaking into ever smaller
groups (highland Scots, Glaswegians, Scotch-Irish). The members of each
clan do not necessarily think their people have gotten the best break
regarding their political or economic place in the world, but they do
not doubt the intrinsic, unique merits of their particular clan.
How does this clannish self-esteem come about? Any one dimension,
including intelligence, clearly plays only a small part. The self-
esteem is based on a mix of qualities. These packages of qualities are
incomparable across clans. The mixes are too complex, the metrics are
too different, the qualities are too numerous to lend themselves to a
weighting scheme that everyone could agree upon. The Irish have a way
with words; the Irish also give high marks to having a way with words in
the pantheon of human abilities. The Russians see themselves as soulful;
they give high marks to soulfulness. The Scotch-Irish who moved to
America tended to be cantankerous, restless and violent. Well, say the
American Scotch-Irish proudly, these qualities made for terrific
pioneers.
We offer this hypothesis: Clans tend to order the world, putting
themselves on top, not because each clan has an inflated idea of its own
virtues, but because each is using a weighting algorithm that genuinely
works out that way. One of us had a conversation with a Thai many years
ago about the Thai attitude toward Americans. Americans have technology
and capabilities that the Thais do not have, he said, just as the
elephant is stronger than a human. "But," he said with a shrug, "who
wants to be an elephant?" We do not consider his view quaint. There is
an internally consistent logic that legitimately might lead a Thai to
conclude that being born Thai gives one a better chance of becoming a
complete human being than being born American. He may not be right, but
he is not necessarily wrong.
If these observations have merit, why is it that one human clan
occasionally develops a deep-seated sense of ethnic inferiority vis-
a-vis another clan? History suggests that the reasons tend to be
independent of any particular qualities of the two groups, but instead
are commonly rooted in historical confrontations. When one clan has been
physically subjugated by another, the psychological reactions are
complex and long-lasting. The academic literature on political
development is filled with studies of the reactions of colonized peoples
that prove this case. These self-denigrating reactions are not limited
to the common people; if anything, they are most profound among the
local elites. Consider, for example, the deeply ambivalent attitudes of
Indian elites toward the British. The Indian cultural heritage is
glittering, but that heritage was not enough to protect Indian elites
from the psychological ravages of being subjugated.
Applying these observations to the American case and to relations
between blacks and whites suggests a new way of conceptualizing the
familiar "legacy of slavery" arguments. It is not just that slavery
surely had lasting effects on black culture, nor even that slavery had a
broad negative effect on black self-confidence and self-esteem, but more
specifically that the experience of slavery perverted and stunted the
evolution of the ethnocentric algorithm that American blacks would have
developed in the normal course of events. Whites did everything in their
power to explain away or belittle every sign of talent, virtue or
superiority among blacks. They had to--if the slaves were superior in
qualities that whites themselves valued, where was the moral justificati
on for keeping them enslaved? And so everything that African Americans
did well had to be cast in terms that belittled the quality in question.
Even to try to document this point leaves one open to charges of
condescension, so successfully did whites manage to coopt the value
judgments. Most obviously, it is impossible to speak straightforwardly
about the dominance of many black athletes without being subject to
accusations that one is being backhandedly anti-black.
The nervous concern about racial inferiority in the United States is
best seen as a variation on the colonial experience. It is in the
process of diminishing as African Americans define for themselves that
mix of qualities that makes the American black clan unique and
(appropriately in the eyes of the clan) superior. It emerges in fiction
by black authors and in a growing body of work by black scholars. It is
also happening in the streets. The process is not only normal and
healthy; it is essential.
In making these points, there are several things we are not saying that
need to be spelled out. We are not giving up on the melting pot.
Italians all over America who live in neighborhoods without a single
other Italian, and who may technically have more non-Italian than
Italian blood, continue to take pride in their Italian heritage in the
ways we have described. The same may be said of other ethnic clans. For
that matter, we could as easily have used the examples of Texans and
Minnesotans as of Thais and Scotch-Irish in describing the ways in which
people naturally take pride in their group. Americans often see
themselves as members of several clans at the same time--and think of
themselves as 100 percent American as well. It is one of America' s most
glorious qualities.
We are also not trying to tell African Americans or anyone else what
qualities should be weighted in their algorithm. Our point is precisely
the opposite: no one needs to tell any clan how to come up with a way of
seeing itself that is satisfactory; it is one of those things that human
communities know how to do quite well when left alone to do it. Still
less are we saying that the children from any clan should not, say,
study calculus because studying calculus is not part of the clan's
heritage. Individuals strike out on their own, making their way in the
Great World according to what they bring to their endeavors as
individuals--and can still take comfort and pride in their group
affiliations. Of course there are complications and tensions in this
process. The tighter the clan, the more likely it is to look
suspiciously on their children who depart for the Great World--and yet
also, the more proudly it is likely to boast of their successes once
they have made it, and the more likely that the children will one day
restore some of their ties with the clan they left behind. This is one
of the classic American dramas.
We are not preaching multiculturalism. Our point is not that everything
is relative and the accomplishments of each culture and ethnic group are
just as good as those of every other culture and ethnic group. Instead,
we are saying a good word for a certain kind of ethnocentrism. Given a
chance, each clan will add up its accomplishments using its own
weighting system, will encounter the world with confidence in its own
worth and, most importantly, will be unconcerned about comparing its
accomplishments line-by-line with those of any other clan. This is wise
ethnocentrism. In the context of intelligence and I.Q. scores, we are
urging that it is foolish ethnocentrism on the part of European
Americans to assume that mean differences in I.Q. among ethnic groups
must mean that those who rank lower on that particular dimension are
required to be miserable about it--all the more foolish because the
group I.Q. of the prototypical American clan, white Protestants, is some
rungs from the top.
It is a difficult point to make persuasively, because the undoubted
reality of our era is that group differences in intelligence are
intensely threatening and feared. One may reasonably ask what point
there is in speculating about some better arrangement in which it
wouldn't matter. And yet there remain stubborn counterfactuals that give
reason for thinking that inequalities in intelligence need not be
feared- -not just theoretically, but practically.
We put it as a hypothesis that lends itself to empirical test: hardly
anyone feels inferior to people who have higher I.Q.s. If you doubt
this, put it to yourself. You surely have known many people who are
conspicuously smarter than you are, in terms of sheer intellectual
horsepower. Certainly we have. There have been occasions when we thought
it would be nice to be as smart as these other people. But, like the
Thai who asked, "Who wants to be an elephant?" we have not felt inferior
to our brilliant friends, nor have we wanted to trade places with them.
We have felt a little sorry for some of them, thinking that despite
their high intelligence they lacked other qualities that we possessed
and that we valued more highly than their extra I.Q. points.
When we have remarked upon this to friends, their reaction has often
been, "That's fine for you to say, because you're smart enough already."
But we are making a more ambitious argument: it is not just people with
high I.Q.s who don't feel inferior to people with even higher I.Q.s. The
rule holds true all along the I.Q. continuum.
It is hard to get intellectuals to accept this, because of another
phenomenon that we present as a hypothesis, but are fairly confident can
be verified: people with high I.Q.s tend to condescend to people with
lower I.Q.s. Once again, put yourself to the test. Suppose we point to a
person with an I.Q. thirty points lower than yours. Would you be willing
to trade places with him? Do you instinctively feel a little sorry for
him? Here, we have found the answers from friends to be more reluctant,
and usually a little embarrassed, but generally they have been "no" and
"yes," respectively. Isn't it remarkable: just about everyone seems to
think that his level of intelligence is enough, that any less than his
isn't as good, but that any more than his isn't such a big deal.
In other words, we propose that the same thing goes on within
individuals as within clans. In practice, not just idealistically,
people do not judge themselves as human beings by the size of their
I.Q.s. Instead, they bring to bear a multidimensional judgment of
themselves that lets them take satisfaction in who they are. Surely a
person with an I.Q. of 90 sometimes wishes he had an I.Q. of 120, just
as a person with an I.Q. of 120 sometimes wishes he had an I.Q. of 150.
But it is presumptuous, though a curiously common presumption among
intellectuals, to think that someone with an I.Q. of 90 must feel
inferior to those who are smarter, just as it is presumptuous to think a
white person must feel threatened by a group difference that probably
exists between whites and Japanese, a gentile must feel threatened by a
group difference that certainly exists between gentiles and Jews or a
black person must feel threatened by a group difference between blacks
and whites. It is possible to look ahead to a world in which the
glorious hodgepodge of inequalities of ethnic groups--genetic and
environmental, permanent and temporary--can be not only accepted but
celebrated.
This difficult topic calls up an unending sequence of questions. How can
intelligence be treated as just one of many qualities when the
marketplace puts such a large monetary premium on it? How can one hope
that people who are on the lower end of the I.Q. range find places of
dignity in the world when the niches they used to hold in society are
being devalued? Since the world tends to be run by people who are
winners in the I.Q. lottery, how can one hope that societies will be
structured so that the lucky ones do not continually run society for
their own benefit?
These are all large questions, exceedingly complex questions--but they
are no longer about ethnic variations in intelligence. They are about
human variation in intelligence. They, not ethnic differences, are worth
writing a book about--and that's what we did. Ethnic differences must be
dreaded only to the extent that people insist on dreading them. People
certainly are doing so- -that much is not in dispute. What we have tried
to do here, in a preliminary and no doubt clumsy way, is to begin to
talk about the reasons why they need not.
These are all large questions, exceedingly complex questions--but they
are no longer about ethnic variations in intelligence. They are about
human variation in intelligence. They, not ethnic differences, are worth
writing a book about--and that's what we did. Ethnic differences must be
dreaded only to the extent that people insist on dreading them. People
certainly are doing so- -that much is not in dispute. What we have tried
to do here, in a preliminary and no doubt clumsy way, is to begin to
talk about the reasons why they need not.