The gap appears before children enter kindergarten and it persists into adulthood. It has narrowed since , but the typical American black still scores below 75 percent of American whites on almost every standardized test.
This statistic does not imply, of course, that all blacks score below all whites. There is a lot of overlap between the two groups. Nonetheless, the test score gap is large enough to have significant social and economic consequences.
Closing the black-white test score gap would probably do more to promote racial equality in the United States than any other strategy now under serious discussion. Judging by the currently available statistical evidence, eliminating the test score gap would sharply increase black college graduation rates, making them nearly equal to white rates.
Such a change would also allow selective colleges to phase out racial preferences in admission, which have long been a flashpoint for racial conflict. Narrowing the test score gap would require continuous effort by both blacks and whites, and it would probably take more than one generation. But we think it can be done. This conviction rests on three facts.
First, black-white differences in academic achievement have narrowed since The National Assessment of Educational Progress NAEP data on year-olds show that the reading gap narrowed more than two-fifths between and The math gap has also narrowed, though not as much.
Five major national surveys of high school seniors conducted since show the same trend. So do surveys of younger students. Second, even IQ scores clearly respond to changes in the environment. IQ scores, for example, have risen dramatically throughout the world since the s. In America, 82 percent of those who took the Stanford-Binet test in scored above the average for individuals of the same age.
The average black did about as well on the Stanford-Binet test in as the average white did in In particular, many of them argue that black people fare worse than white people because they tend to be less naturally intelligent. Although race science has been repeatedly debunked by scholarly research, in recent years it has made a comeback. If you believe that poor people are poor because they are inherently less intelligent, then it is easy to leap to the conclusion that liberal remedies, such as affirmative action or foreign aid, are doomed to fail.
There are scores of recent examples of rightwingers banging the drum for race science. One of the people behind the revival of race science was, not long ago, a mainstream figure. In , Nicholas Wade, a former New York Times science correspondent, wrote what must rank as the most toxic book on race science to appear in the last 20 years. The book argued that poor people, and particularly poor black people, were inherently less intelligent than white or Asian people. When it was first published in , it became a New York Times bestseller, but over the next few years it was picked to pieces by academic critics.
As a frequent target for protest on college campuses, Murray has become a figurehead for conservatives who want to portray progressives as unthinking hypocrites who have abandoned the principles of open discourse that underwrite a liberal society. And this logic has prompted some mainstream cultural figures to embrace Murray as an icon of scientific debate, or at least as an emblem of their own openness to the possibility that the truth can, at times, be uncomfortable.
Last April, Murray appeared on the podcast of the popular nonfiction author Sam Harris. In the past, race science has shaped not only political discourse, but also public policy.
Now, as race science leaches back into mainstream discourse, it has also been mainlined into the upper echelons of the US government through figures such as Bannon. This has left an opening for people such as Murray and Wade, in conjunction with their media boosters, to hold themselves up as humble defenders of rational enquiry. Which raises the question: why, exactly, are the race scientists wrong? R ace, like intelligence, is a notoriously slippery concept. Individuals often share more genes with members of other races than with members of their own race.
Race science therefore starts out on treacherous scientific footing. The supposed science of race is at least as old as slavery and colonialism, and it was considered conventional wisdom in many western countries until Though it was rejected by a new generation of scholars and humanists after the Holocaust, it began to bubble up again in the s, and has returned to mainstream discourse every so often since then. In , during my final year in state high school in apartheid South Africa, a sociology lecturer from the local university addressed us and then took questions.
He was asked whether black people were as intelligent as white people. No, he said: IQ tests show that white people are more intelligent. In apartheid South Africa, the idea that each race had its own character, personality traits and intellectual potential was part of the justification for the system of white rule.
The recent revival of ideas about race and IQ began with a seemingly benign scientific observation. In their paper, the anthropologists argued that high IQ scores among Ashkenazi Jews indicated that they evolved to be smarter than anyone else including other groups of Jews.
People who do this less well than others may have intellectual deficits or they may be suffering from poor educational exposure, trauma, poisoning or even from poverty. So IQ is a useful metric for perceiving such limitations, but NOT for discerning that one has a genetic or permanent intellectual decrease: unfortunately it is routinely interpreted in this manner to claim the innately lower intelligence of dark-skinned people.
The number of gifted African American children in the district soared 80 percent, and that of gifted Hispanic children immediately skyrocketed percent. However not all Asians are accorded high scores, and the higher scores are use to reinforce the model minority myth— and to demonize Asians. The average gap between African American and white IQs is narrowing, which some ascribe to greater access to higher education but more study is needed to understand it.
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But without being able to measure the effect of being treated as sub-normal, and of an historical legacy of slavery and discrimination, how do we know whether its average effect is sufficient to lower Black IQ 15 points, or less than that—or more than that? Given the social importance of this issue, guessing is not appropriate. Herrnstein and Murray have heard appeals to the legacy of slavery and discrimination. And they have a response which appeals both to the pattern of racial differences and their magnitude.
First, the pattern. And this leads them to ask:. We have not been able to think of a plausible reason. 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.
But these facts are not hard to understand. Blacks and Whites are to some extent separate cultural groups, and there is no reason to think that a measure like socio-economic status means the same thing for every culture.
Herrnstein and Murray mention the work of John Ogbu, an anthropologist who has distinguished a number of types of oppressed minorities. He distinguishes them from groups like Chinese and Jews who are voluntary immigrants and have a culture of self-respect.
If higher socio-economic status Blacks still are to some extent part of a caste-like minority, then they will be at an environmental disadvantage relative to higher socio-economic status Whites. But low status Blacks and Whites are more likely to share a caste background.
As Henry Louis Gates, Jr. Most middle-class Blacks have arrived in the middle classes relatively recently, many of them under less than ideal conditions for the development of self-respect. It would be surprising if children of these newly middle-class Blacks were to have fully escaped their caste background in so short a time. Herrnstein and Murray think this is implausible because when you look at environmental measures—for example, parental income, school quality—you do not find that 94 percent of Whites have a better environment than the average Black.
The difference is entirely environmental despite the probable substantial heritability within each group. Using the same procedures as Herrnstein and Murray, Flynn calculates that 99 percent of the group had to have a better environment for the development of IQ than the average member of the group.
Given differences of this magnitude among people of a uniform culture who are separated by only a single generation, is it really so implausible that 94 percent of Whites have an environment better than a Black at the 50th percentile? Environmental differences, then, including the sort that affect Black Americans, are known to have large effects on IQ. Moreover, we currently have no way to quantify these effects. So we should draw no conclusion about the probability of any Black genetic IQ advantage or disadvantage.
As applied to the case of IQ, then, the Fundamental Principle is false: the combination of high heritability within the White population, and persistent Black-White differences, does not support a case for genetic differences. Earlier, I commented that if we knew nothing at all about two groups except that they differed by 15 points in IQ and that IQ is heritable in both, and we had to guess the causes, it might seem sensible to guess that the lower scoring group was disadvantaged both genetically and environmentally.
Consider a culture in which red-haired children are beaten over the head regularly, but all other children are treated well. This effect will increase the measured heritability of IQ because red-haired identical twins will tend to resemble one another in IQ because they will both have low IQs no matter what the social class of the family in which they are raised. By contrast, a gene affects a characteristic indirectly by producing a direct effect which interacts with the environment so as to affect the characteristic.
In the hypothetical example, the red-hair genes affect IQ indirectly. In the case of IQ, no one has any idea how to separate out direct from indirect genetic effects because no one has much of an idea how genes and environment affect IQ. The methodology used to measure heritability obscures this ignorance by counting differences in characteristics as caused by genetic differences whenever there is a genetic difference, even if there is also an environmental difference.
This distorts the ways we normally think about causation. For instance, the heritability methodology focuses on the difference between the red-hair genes and genes for other hair colors, not on the fact that red-haired children—unlike blond children—are beaten. When virtually only women were wearing earrings, variation in earrings was as much social as genetic, but counted as highly heritable.
If there is a genetic difference in the causal chains that lead to different characteristics, the difference counts as genetically caused even if the environmental differences are just as important. If we adopted the opposite convention—concluding from any environmental difference in two causal chains that the differences are environmentally caused—then we could not use current methodology for measuring heritability, because we have no general method of detecting indirect genetic effects using current techniques.
Heritabilities using the two different conventions would be radically different if there are substantial indirect genetic effects. Recall the examples mentioned earlier about the measured heritabilities of such quantities as number of hours of watching TV.
No one should suppose that there is variation in genes for watching TV; this is a case of indirect effects. I mentioned earlier that if you place a pair of Black one-egg twins in different homes, you automatically fail to randomize environments, because the Black twins will bring part of their environment with them; they are both Black and will be treated as Black.
This is an indirect genetic effect par excellence. Implicitly, everyone in this field recognizes that, yet more subtle possibilities of indirect effects are typically ignored. Recall that heritability is defined as a fraction: variation due to genetic differences divided by total variation. The measure of variation that is always used though alternatives are available is a statistical quantity known as variance.
One factor that raises variance is a positive correlation between genetic and environmental variables. Suppose that children whose genes give them an advantage in musical talent tend to have parents who provide them with an environment conducive to developing that talent—music lessons, concerts, a great CD collection, musical discussion over dinner, etc. Suppose further that other children who have a genetic disadvantage also have an environment that stultifies their musical talents.
The correlation between genes and environment will move children towards the extremes of the distribution, increasing the variance in musical skills.
It is common in behavior genetics to distinguish among a number of different types of covariance. With active covariance, the child creates a gene-environment correlation, as when a musically talented child practices musical themes in the imagination or pays attention to the musical environment.
But reactive and active covariance cannot be measured without specific hypotheses about how the environment affects IQ. And as I observed, little is known—as all parties to the disagreements about genetics and IQ agree—about how the environment affects IQ.
These points about covariance assume that there are genes for IQ and that these genes may affect the environment so as to produce effects on IQ that are correlated with the ones that the genes themselves produce. But this way of presenting the issue seriously underestimates its significance. Of course, adults could give some children more attention than others without producing IQ differences, but differences might result from variations in adult attention.
Suppose further that personal attractiveness and self-confidence are highly heritable. Then we would have an indirect effect par excellence , and such an effect could, for all we know, largely account for the heritability of IQ. Without an understanding of how the environment affects IQ, we simply have no way of determining how much of the variance in IQ is indirect genetic variance of this sort. Of course, if we knew that some specific adult behavior that is triggered by some specific heritable property of children was responsible for a large component of IQ variation, then we could measure that behavior.
But there is no theory of intelligence or IQ that would allow us to have any synoptic grip on such factors.
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