The Irrelevance of Genetics

...In any case, Jensen's position is not without significant flaws, and these should be pointed out...

...environmental differences, on the other hand, appear to be more appropriate targets for public policy...

...In fact-contrary to popular belief-the practical relevance of estimating the effects of genes on IQ is almost zero, since genetics tells us nothing about people's ability to learn and develop...

...Yet, in view of the historical treatment of blacks, it does not seem unreasonable to maintain that the average black environment is "that bad...

...Now that dreadful mistake has become a 400-page book, and must be dealt with more seriously...

...Nonetheless, one cannot help feeling that to some extent at least Jensen has brought it all on himself...

...Attending an integrated school, for example, apparently raises the average black's score a mere three or four points...

...Finally, Jensen states that commonly measured environmental variables like socioeconomic status, schooling and test-taking motivation cannot explain the black-white IQ difference, and he gives a reasonably good summary of the current literature...

...His critics contend that the test variations are the product of subtle environmental and motivational factors, deriving from the long history of racial oppression in this country, and probably working themselves out at present in different value systems and child-rearing practices...

...For this reason, it is important to understand what population genetics can legitimately contribute to public debate...

...Inevitably, therefore, a relationship exists between IQ scores and adult success...

...A person with extremely high genetic potential but lacking adequate opportunities will learn very little, whereas a person with low genetic potential can, given an environment that is sufficiently intense, learn almost anything...

...Jensen's second line of argument compares black-white differences on a number of tests-from "pure" nonverbal IQ examinations to those demanding a high degree of verbal and cultural knowledge-and concludes that the black-white gap is largest on the nonverbal tests...

...Technical critiques of Jensen's methodology proliferated after the publication of the Harvard Educational Review article, and many of them pointed out that the evidence is not as consistent and airtight as Jensen suggests...

...Were IQ differences due entirely to variations in genes, children would still know more at age 16 than they did at age 6. How much and how fast individuals learn is largely determined by the experiences they are exposed to...

...Moreover, even if the disadvantaged could be helped to raise their IQ scores, their economic situation would not improve significantly...

...In short, while Jensen's name may now be a household word, his work has practically no relevance to public policy disputes...

...There is a fairly strong relationship between good performance on IQ examinations and staying in school, and also between staying in school and economic achievement...

...This section of the piece was widely and rightly criticized...

...The preface is also an intriguing and appalling tale of the politics of research...

...Educability and Group Differences develops the most controversial part of that article into a book-length thesis that dissimilarities between groups-Specifically the 15-point average IQ difference between blacks and whites-are also genetic in origin...

...Jensen has been the target of student demonstrations...

...Those who are worried about social and economic reform need not involve themselves overly with Jensen's findings...

...In his Review article, Jensen sketched out the argument that racial IQ differences, like individual differences, have a substantial genetic component...

...Jensen suggests that the major cause of IQ disparities may well be genetic, and he marshals a book full of inferential evidence to support his claim...

...Still, this book is a clear and informative beginning for those interested in the technicalities of the subject...

...In sum, Jensen's evidence is far from conclusive, and it is too bad that his valuable contributions to the field of population genetics will undoubtedly be lost amid charges and countercharges of racism and general wickedness...

...Genetic differences are seen as permanent and personal...

...Of course, Genetics and Education is hardly the last word on the subject...

...The smallest differences, in contrast, occur on a measure of memory and on a figure-copying exercise, tests that are as "nonverbal" as one can imagine...

...His name-like Senator Joseph McCarthy's-has even been turned by his opponents into an "ism...

...Surely these are verbal areas requiring cultural knowledge...

...Educability and Group Differences is another matter...

...Such a finding would, if true, refute the environmentalists' claim that the poor performance of blacks is due to the cultural bias of the examinations...

...Yet people react more heatedly to arguments based on genetic differences than they do to those that point to environmental differences for a variety of logical and illogical reasons...

...Although this contention is true, to say that commonly measured environmental variables cannot account for the racial gap is not to say that the gap is due to genetic makeup...

...In his first line of argument Jensen calculates the size of the environmental difference which would be necessary to account for the disparities between the average black and white IQ score, and concludes that the average black would have to have been exposed to an environment worse than that of almost all whites...

...Jensen explains the conceptual background of IQ testing as well as anyone...

...Unfortunately, it is not the conclusion likely to be drawn by most of Jensen's readers...

...And he ends Educability and Group Differences, as well as the two long essays of Genetics and Education, with a plea for attention to human diversity...

...One can expect that it, too, will be considered a rationalization for social inequity, even though Jensen has clearly dissociated himself from this interpretation...

...When "How Much Can We Boost IQ and Scholastic Achievement," the most important piece in Genetics and Education, first appeared four years ago in the Harvard Educational Review, it was seen as a counsel of despair for those trying to improve the life chances of the poor, as a "scientific" justification for racial inequalities?and it will probably be seen that way now...

...Yet anyone who examines these two books with an eye toward public policy might well wonder what the fuss is all about...

...For, according to Jensen, his investigations' major finding, in terms of practical application, is that children have different ways of learning...

...At the time, though, it was possible to maintain that including the material on race was just a dreadful mistake on the part of Jensen and the Review's editors...

...Educational policy does not have to fail because genes influence test scores...

...But the limited earnings of disadvantaged people have much more to do with discrimination in the job market than with low IQ scores...

...Schools, he says, ought to make serious efforts to tailor teaching strategies to individual learning styles and capacities...

...In the large study that he relies on, the greatest black-white differences are to be found in the categories of word meaning, language (grammar) and paragraph meaning...

...This is not, however, to deny the intrinsic interest of heritability estimates, or that Genetics and Education is a useful introduction to a fascinating line of intellectual inquiry...

...neither implies that it is impossible...

...Reviewed by Mary Jo Bane Research Associate and Lecturer in Education, Center for Educational Policy Research, Harvard University Arthur Jensen's pronouncements on IQ-especially his contention that IQ variations between individuals are almost entirely genetic in origin-have produced heated arguments among scientists and educators...

...Social science has made relatively little progress in understanding the sources of IQ differences between groups, but it does not seem that discriminatory treatment alone-be it economic or educational-Is sufficient explanation for the test results...

...This is hardly a conclusion to send people rushing to the barricades...

...Unfortunately, there is no scale for actually measuring variations in family environments that could settle the question, so the issue must remain open...

...He then asserts, in effect, that black environments cannot be that bad, and thus the two groups' genetic potentials are probably not equal...

...But Jensen's data do not support his own position...

...One attempt to reconcile all the available American data concluded that the proportion of a person's IQ score attributable to heredity is probably closer to 45 per cent than to Jensen's estimate of 80 per cent...

...Both explanations imply that achieving complete equality in test performance will be difficult...

...In addition, he describes the procedures for calculating heritability and summarizes the available data quite competently...