Commentary Magazine


Heredity vs. Environment

To the Editor:

David K. Cohen [“Does IQ Matter?,” April] argues that IQ is not very important in determining social status in America, not as important as education, and so, he says, a hereditary meritocracy does not loom in our future. But, as he acknowledges, IQ and education are substantially correlated. And he further acknowledges that IQ is substantially heritable. It turns out that those two facts undermine his case, for they suggest that educational achievement in America is itself heritable. Only if education depended exclusively on that relatively small component of variation in IQ that is not inherited could education be non-genetic, and there is no support for that improbability. In fact, surmise is unnecessary, for the existing data imply a sizable heritability of .5 to .6 for educational achievement, although the figure is not nearly so firmly fixed as is the .75-.85 for IQ. Taking him entirely at face value, then, we are still confronted with the likelihood of social stratification based to some extent on genetic endowment.

In the future, says Mr. Cohen, we will have greater equality of education. I hope he is right, but what does that portend for the sorting out of people into the scale of occupations? Let us assume for argument’s sake that we succeed somehow in educating everybody equally (another improbability). What would predict social standing then? Of course, we could further assume that social standing is therefore also equalized, but that is too easy a solution to the egalitarian’s problem. If there are social classes, and if education has been equalized, then the two can no longer be correlated. As Mr. Cohen doubtless knows, removing a source of variance like education must, other things being equal, increase the magnitude of the correlation between social class and its other correlates, among them IQ. Mr. Cohen says, perhaps anticipating this rejoinder, that IQ has no effect on people’s jobs independent of their schooling. While it is true that some studies have failed to uncover an independent effect of IQ, that could easily be because IQ and schooling in those studies were closely linked to begin with. What Mr. Cohen does not, and cannot, say is that if IQ and schooling were sufficiently decorrelated—by equalizing education—to take the heritability and predictive validity out of schooling, IQ would still have no independent effect.

Mr. Cohen mentions other factors that may contribute to job status—enterprise, motivation, preferences, and “the luck of the draw,” as if the operation of these argued against a meritocracy. In three out of those four, there may be, and likely are, genetic elements, further contributing to the biological basis of social status. In my article on IQ which Mr. Cohen criticizes, I noted that IQ probably ties into only one of the several genetic parameters of social status. I had in mind other parameters like enterprise and interest, plus still others, like temperament, even physical stamina, health, and appearance. Mr. Cohen’s apparent insensitivity to the possible genetic elements in these other socially important dimensions of variation is further proof that the study of the biological roots of human society has languished too long in the shadow of the temple of the environmentalist dogma, depriving us of a balanced prospect. Because we know so much about both its heritability and its predictive validity, the IQ, rather than those other parameters, seemed to me a good place to begin to shed a little light. After Mr. Cohen’s article, I still think so.

R. J. Herrnstein
Harvard University
Cambridge, Massachusetts

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To the Editor:

David K. Cohen’s article makes an excellent case for the abandonment of IQ as a guidepost in the fight over equal educational opportunities for the races. . . . Mr. Cohen makes it perfectly clear that success is not something that can be predicted by a scale designed to measure potential but seems rather to depend on the determination of the individual. One point Mr. Cohen makes deserves more attention. He states that the findings of an experiment under way in Milwaukee show that children from poor families, given an enriched environment, can make formidable gains in IQ. He also states that evidence has shown that “as the experience recedes into the past so does the effect diminish.” But this only proves that the white child (or black) in a superior environment maintains his IQ advantage because his superior environment is also maintained.

The failure of both integrated classes and separate-but-equal segregated classes to produce academic proficiency in ghetto blacks proves not that the black children are genetically inferior but that they are environmentally inferior. . . .

Jon May
Clearwater, Florida

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To the Editor:

. . . To worry about “nature vs. nurture,” is to beat a dead horse. The variables are too many and too difficult to control to enable us to reach a conclusion about the effectiveness of one or the other upon our destiny. Individuals succeed despite the uncontrollable variables in the environment if they are of a mind to. Neither a good home, nor a good school, nor a long or short term within a particular educational environment, has much to do with it.

R. F. Becker
Michigan State University
Bloomfield Hills, Michigan

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To the Editor:

David K. Cohen succeeds in avoiding the central meaning of the IQ: that the IQ is, after all, a device which should enable clinicians, psychologists, and educators to filter out those children who—in the words of Binet and Simon—are “unable to profit, in an average measure, from the instruction given in the ordinary schools.” When IQ is dissociated from its statistical and, hence, its artificial, prognostic significance, it becomes a measure of a given individual’s ability to score—at a given point in time—on a specific test. In the setting of Israel’s kibbutzim, a relatively uniform environmental setting obtains with reference both to the learning situation and to the socialization of the children in a given settlement. These children show some ethnic variation but, as yet, little significant genetic mixing. Under such conditions, there are indications that differences in IQ can be leveled—insofar as formal learning and socialization are concerned—by changing the stimulus for learning for most of the IQ-deficient children. It would follow that it ought to be possible to change the IQ score by changing the test: or, more specifically, by changing the nature of the stimulus used on the test. If our assumptions are in any measure correct, perceptual differences linked to cultural or racial differences lead to IQ deficiencies simply because the test materials are not appropriate to the assessments they undertake to make. . . .

G. M. Stern
Child Guidance Clinic of the Kibbutzim
Haifa, Israel

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To the Editor:

. . . David K. Cohen writes that “the importance of schooling to occupational status may itself be based on a variety of non-intellectual factors. Employers use the school system as an elaborate behavior-screening mechanism, on the theory that certain kinds of work require certain kinds of personalities. . . . Students who have ‘better’ manners, who behave ‘properly,’ who accept authority, and who look the way they should, tend to be routed into higher-status school work and occupations.”

The screening argument is very popular, but makes no sense. Why should a firm pay a college graduate several thousands of dollars more than a high-school or elementary-school graduate simply because, on the average, college graduates are more likely to “behave properly” than those with less schooling? Using a 10-per-cent discount rate, the present value of the extra wages paid by a firm for a college rather than a high-school graduate is $25,000 to $30,000. If the role of schooling were only to screen workers, far less expensive screening techniques (tests or trial periods) could easily be developed.

Perhaps Mr. Cohen thinks he was given his present job because he has better manners, behaves properly, and accepts authority!

Barry R. Chiswick
Queens College
Flushing, New York

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David K. Cohen writes:

R. J. Herrnstein’s letter at least proves that people can disagree endlessly about the same evidence. He thinks that the heritability of IQ and the relation between IQ and educational attainment prove that education is heritable and that meritocracy is upon us. I think that the same evidence shows that IQ is a modest influence on educational attainment, and that success in school depends a lot more on other factors. I think the prospect of meritocracy is much less likely than is that of a social structure based on lots of less attractive criteria, like the ones currently encouraged by schools. Professor Herrnstein parries by saying that those other factors may be heritable too. They may be, but so may be the tone of my voice. The current state of the evidence is such that it supports almost no assertion save that we ought to know more.

Perhaps the most constructive response—and the most useful for those interested in such issues—is to point out that all the disagreements among the professors on these points are treated at great length in a forthcoming book by Christopher Jencks (Inequality, Basic Books, Fall 1972).

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Note: Norman Podhoretz’s column, “Issues,” does not appear this month. Its regular monthly appearance will resume in September.

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