Arthur Jensen Replies to Steven Jay Gould

The following is a review of Gould's Mismeasure of Man , in which Dr. Arthur Jensen replies to Gould's severe criticism of him in the book. Of course, uncritical admirers of Gould will "know" that Jensen is an alleged "racist," and hence anything he says can ever-so-conveniently be automatically be ignored. But those who are open-minded enough to give both sides a fair hearing should read Jensen's reply without any preconceived ideas, and ask themselves: Is this man really the terrible bigot and fool that Gould makes him out to be? Or is he a serious scholar who has been the victim of a slick campaign to paint him as a scoundrel because his findings contradict certain political ideologies? Jensen's reply has, until now, only been seen by a miniscule fraction of those who have read Gould's Mismeasure . It is now time for the "other side" to be heard.

THE DEBUNKING OF SCIENTIFIC FOSSILS AND STRAW PERSONS Arthur R. Jensen

Contemporary Education Review

Summer 1982, Volume 1, Number 2, pp. 121- 135.

The Mismeasure of Man

New York: W. W. Norton, 1981

by Stephen Jay Gould

ARTHUR R. JENSEN is Professor of Educational Psychology, University of California, Berkeley, CA 94720. His areas of specialization are Differential Psychology, Psychometrics and Behavioral Genetics. Recent publications include Straight Talk about Mental Tests , New York: The Free Press, 1981. Dr. Jensen received his B.A. at UC, Berkeley and his Ph.D. at Columbia University.

This book concerns the biasing influence that social ideology may have on purportedly objective science- the behavioral and brain sciences especially and psychometrics in particular. Ironically, the book itself serves as a patent example of its own thesis.

Stephen Jay Gould is a paleontologist at Harvard's Museum of Comparative Zoology and offers a course at Harvard entitled, "Biology as a Social Weapon." Apparently the course covers much the same content as does the present book. Having had some personal cause for interest in ideologically motivated attacks on biologically oriented behavioral scientists, I first took notice of Gould when he played a prominent role in a group called Science for the People and in that group's attack on the theories of Harvard zoologist Edward 0. Wilson, a leader in the development of sociobiology (BioSciences, March, 1976, Vol. 26, No. 3). I wonder if Gould's present book is an example of his idea of "science for the people"? It is written in a popular and sometimes engagingly entertaining style; it is filled with "human interest," and with vivid accounts of eminent but self deluding, cheating, and foolish scientific figures of the past- a kind of intellectual morality play of wrong doing (or wrong thinking); it focuses on accounts of subsequent "recanting" by the "big names" in the history of mental testing, those wittingly or unwittingly self- deceived bad guys in this "tale of zealotry." ("Goddard recants," "Brigham recants," "Terman recants," "Spearman recanted," etc. Indeed, whenever a scientist alters his view on some point over a 20 year period, or later places a different emphasis on some particular fact, Gould insistently refers to his "recanting.") Naive readers might develop a gut- level dislike for the many reactionary elitist schemers exposed in Gould's book. But then readers will be gratefully relieved to see all the villains toppled to ignominy for their egregious fallacies.

Most of the reviews of the book which I have seen thus far in the popular press already bear out half of my prediction: Gould's book will receive much more uncritically favorable and sentimentally sympathetic reviews from the professional literati in the popular press (it has won official acclaim from the National Book Critics' Award) than it will receive in the technical journals at the hands of qualified professionals in the relevant fields. (I have not yet seen any reviews in the technical journals.) Gould's debunking expedition offers many an easy target to critics with an intimate knowledge of the topics discussed. Before taking aim at those specific points, which I feel most competent to criticize, I shall first try to abstract the main message of Gould's book from his own perspective.

Overview of Gould's Thesis

Underlying all the varied detail of Gould's exposition is a philosophy of science, or rather a sociology of science, which emphasizes the notion that scientific endeavor generally is not so much a search for o objective knowledge as it is a sociopolitical activity, reflecting the social context and value systems within which individual scientists do their work. According to this view, socially conditioned presuppositions or prior prejudices about the nature of society force even "good scientists" to produce theories and conclusions that inevitably confirm their own social prejudices and lend to them additional support in the guise of scientific truth.

This charge of a social, value-laden science undoubtedly contains an element of truth. In recent years, however, we recognize this charge as the keystone of the Marxist interpretation of the history of science. In this view, science is motivated to promote that form of socioeconomic class structure that most favors the privileged elite, reinforcing its position of political and economic power. By the same token, any unwitting biases of scientists are deemed most prone to line up against the socially underprivileged and economically disadvantaged classes. Presumably, such ideological science only pretends to test its hypotheses in the idealized, objective manner we learned about in our introductory high school and college science courses. In this view, scientists actually, begin with prejudices, then frame them as theories, and create only the illusion of demonstrating the validity of their hypotheses. The conclusions are, to use Gould's apt phrase, "advocacy masquerading as objectivity." This end is accomplished through "biased selection" --of data, of methods of analysis, and of various possible interpretations of evidence- such that the final outcome will confirm whatever dogma originally motivated the supposedly objective search for the truth. This theme is the foundation of the seven chapters of Gould's opus.

According to Gould, the inescapable dialectic of science and social ideology is best illustrated in the behavioral sciences through the agency of several long-lived and closely intertwined key beliefs.

Biological determinism is the poison root. This notion (a "lie," according to Gould) is manifested in the attempt to discover, or failing that, to invent, some biological (i.e. nature- given) justification for "ranking people" (or groups of people) according to their "inborn worth." Biological determinism is a "theory of limits," which assumes that the current status of different races and social groups is an inevitable consequence of their "innate worth." By Gould's definition, biological determinism essentially is the attempt to make nature an accomplice in the crime of political and socioeconomic inequality. It arises in a political context to serve the group in power. Its perpetuation depends on the myth that science is an objective enterprise, whereas science actually mirrors the predominantly religious or political ideology of its time. Biological determinists in the human sciences are claimed to be identified with politically conservative and reactionary ideologies. The centrality of this theme for Gould is shown by his claim that he was inspired to write the book "because biological determinism is rising in popularity again, as it always does in times of political retrenchment." Hence, the book is primarily an attack on "biological determinism" as it applies to human mental ability.

By what means can the "lie" of biological determinism be sustained by the establishment? How can this reactionary hope, belief, or claim (viz., that "worth" can be assigned to individuals or groups) be implemented, while still maintaining the appearance of objective, scientific sanction?

Intelligence , or rather the concept that intelligence can be measured as a "single quantity," is the answer. Gould portrays this concept as utterly fallacious. Indeed, Gould characterizes the attempt of psychometrists, past and present, at the quantification of intelligence, as the attempt to assign "all individuals to their proper status in a single series." But how can this scheme be made scientifically believable? How can we justify scientifically the determination of people's "worth" on the basis of assigning a single number or score on an "intelligence test" to each person?

Reification of the concept of intelligence is the answer, according to Gould. By converting an abstract concept, intelligence, into a "unitary thing," a "single substance," an "object" (all Gould's words) that occupies space inside the brain, the pioneer psychometrists established the essential rationale for ranking individuals, social classes, and races on a unidimensional scale of "worth." The awful fallacy of reifying intelligence (or Spearman's g, the general factor common to a large number of cognitive abilities) becomes a central theme in Gould's account. The conscious or unconscious motive behind this reification of general mental ability, or intelligence, is that such reification presumably is demanded by the dogma of biological determinism. The "quantification" and the reification of intelligence facilitate and justify the distinctions and divisions between people, which political and social orders dictate, according to this view.

The whole nefarious, fallacious enterprise is best exemplified by two fields of research: "craniometry," in the 19th century, and its replacement in the 20th century, by "psychometry," particularly intelligence testing. Scorn heaped on the early craniometrists, particularly those concerned with the relationship of brain size to intelligence, should transfer to modern psychometrists who are interested in the measurement and nature of intelligence. "We live in a more subtle century, but the basic arguments never seem to change. . . The crudities of the cranial index have given way to the complexity of intelligence testing" (p.143). To Gould, the old- fashioned craniometric science and modern psychometric science are as parent and offspring. The purpose of both is essentially the same: to prove that the innate construction of people is reflected in their present social and economic roles. Both the outmoded craniometry of the 19th century and the mental tests of the present day have stemmed from the false belief that intelligence is a "thing" in the head, according to the measurement of which all persons, social classes, and races can be ranked in "mental worth"- a term that Gould uses repeatedly (in addition to "innate worth" and "ultimate worth") as a substitute for "intelligence" or "IQ," as if to imply that all these terms are entirely synonymous in present- day psychometrics.

The essential message of Gould's book is epitomized in his own words: "This book. . . is about the abstraction of intelligence as a single entity, its location within the brain, its quantification as one number for each individual, and the use of these numbers to rank people in a single series of worthiness, invariably to find that oppressed and disadvantaged groups- races, classes, or sexes- are innately inferior and deserve their status" (pp. 24- 25).

General Criticisms

Before addressing specific points in each of the chapters, I shall first mention what seems to me to be general deficiencies pervading the work as a whole.

Sociology of Science

First, I think Gould exaggerates the threat of the sociology of science as an obstacle to objective science. Errors, blind spots, and biases on the part of individual scientists have always existed in every scientific field. Yet over the course of time there indisputably has been scientific progress and the growth of objective knowledge in every sphere of scientific endeavor. Of course, the theory that science cannot be objective because it cannot escape the context of social values is itself not exempt from the same generalization. If this theme is overplayed, as it is by Gould, it places its advocate in a position not unlike that of the Greek philosopher's paradox of the Cretan who declared, "All Cretans always lie. " If the statement is true, it must be untrue, and hence need not be taken seriously.

Fortunately, progress in scientific knowledge is distilled out of the endeavors of the many individually imperfect scientists who investigate the same phenomenon. The enterprise succeeds in its aim of objectivity, in the long run, despite the subjective biases of individual scientists and despite the influence of social context as portrayed by the Marxist sociology of science. Mendel's theory is accepted and Lysenko's is rejected (even by the Soviet ideologues who once promoted it), not because one scientist was necessarily a better man than the other, but because there is indeed a reality out there in the realm of phenomena, a reality in terms of which theories can be criticized and tested by innumerable other scientists, albeit each with his or her own individual biases or blind spots, each scrutinizing and testing the others formulations. One chief virtue of science is that, in order to succeed, its practitioners need not be saints or paragons of detached objectivity. When many individual scientists- ordinary men and women with specialized technical competencies- are all able to think as they please and do their research unfettered by collectivist or totalitarian constraints, science is a self- correcting process.

In any case, the Marxist sociology of science, whatever general truth it may contain, cannot exempt the critic from a detailed analysis of any particular theory or empirical claim, showing precisely how it fails as objective science, or why it should be rejected and replaced by some competing formulation or body of evidence. That has always been the normal procedure of science, and we know that it works. At one point, Gould covers himself by claiming this general view: "As a practicing scientist, I share the credo of my colleagues: I believe that a factual reality exists and that science, though often in an obtuse and erratic manner, can learn about it" (p. 22). But Gould would want us to believe that the behavioral sciences are especially unlucky in this regard. That could be. Still, the situation would be by no means hopeless. The behavioral sciences, including differential psychology, psychometrics, and behavioral genetics, surely can be, and for the most partake, normal science.

Unfortunately, Gould's book itself contributes heavily to promoting the ideological encumbrance of these fields. This is a pity. The field is faced with many real problems, which call for objective analysis and research, yet in my judgment Gould's book contributes absolutely nothing to this effort. The Mismeasure of Man attempts to debunk, and, as far as I can make out, attempts to do nothing else. Of course, debunking can be a useful activity in the scientific enterprise, provided the specific objects of attack are real and present issues. The disappointment of this book is its failure really to debunk anything currently regarded as important by scientists in the relevant fields. Because of Gould's peculiar selection of flawed scientific relics as targets for attack, it is hard for me to imagine that this work will impress any but those unfamiliar with current research in these fields, despite the author's evident intelligence and keen literary style. I believe he has succeeded brilliantly in obfuscating all the important open questions that actually concern today's scientists. Instead of taking on the real issues of contemporary research in these fields, paleontologist Gould tilts at a museum collection of scientific fossils and at many a straw person of his own making.

Focus on the Past

The fossil nature of practically all the objects of Gould's expose is suggested by the fact that, although the book is not properly a history of mental testing, most of the key references are amazingly old. Present- day workers in these fields will have nothing to worry about! Few, if any, will consider it worth the bother to dig into such ancient tomes to check the validity of Gould's interpretations. Of all the book's references, a full 27 percent precede 1900. Another 44 percent fall between 1900 and 1950 (60 percent of those are before 1925); and only 29 percent are more recent than 1950. From the total literature spanning more than a century, the few "bad apples" have been hand- picked most aptly to serve Gould's purpose. Yet what relevance to current issues in mental testing are the inadequacies and errors of early anatomical studies by Samuel Morton (who died in 1851) or Paul Broca (who died in 1880) concerning racial- variation in cranial capacity (to which Gould devotes the better part of two chapters): Who now wishes to resurrect Lombroso's (1836- 1909) theory- of physical criminal types; Cyril Burt's 1909 report (his very first publication) of social class differences in intelligence; Goddard's account of the Kallikak family (1912) and the long since discredited theory of "feeblemindedness" as a simple Mendelian character; Terman's pronouncements in 1916 about eugenic measures to reduce the incidence of mental retardation; the primitive 1917 army mental tests; or the U.S. Congress's 1924 Immigration Restriction Act, which cited the 1917 army test data? These antiquated topics, which occupy most of Gould's book, can in no way serve to undermine or discredit current work in physical anthropology, psychometrics, differential psychology, behavioral genetics, and sociobiology. Readers expecting to find a forthright critique of the present status of issues and controversies in these fields are in for disappointment. The closest thing they will find to criticism of contemporary mental testing is the insinuation of its guilt through remote historic lineage.

In distant retrospect, the early history of every science often looks bizarre in some respects. Why should we expect the behavioral and brain sciences to be the great exception? Should we ridicule the Early astronomers for claiming that the Earth is the center of the universe, or the early anatomists for claiming that the heart is the seat of emotion? Why should anyone demand of psychology that it be hatched fully mature and perfect at its very beginnings?

Gould devotes the larger part of a chapter to a minutely detailed and damning critique of the first group mental test ever devised. Yet everyone today would surely agree that the first army tests fall far short of current standards of test theory and construction. Psychometric theory and technology have come a long way since 1917. Indeed, a half- century after the first group tests were used in the army, the office of the Surgeon General estimated that the use of modern tests for selection in the armed forces saves the nation more than $14O million a year in the cost of training recruits after basic training- not a trivial utility for psychology's most practical and most indisputably successful invention.

Gould's exclusive critical focus on forebears (and the worst examples, at that) is much like trying to condemn the modern automobile by merely pointing out the faults of the Model T. An entire chapter is devoted to Lombroso and his school of criminal anthropology! As an undergraduate nearly 40 years ago, I recall learning that Lombroso's theory of "criminal types," all bearing distinctive anatomical stigmata of their moral pathology, had long since been discredited. Although it makes for amusing reading to see Lombroso's old theories once again so enthusiastically panned, Gould's motive in reviewing them seems clear. The Lombroso critique serves merely as a long prelude to the short epilogue of this chapter, which disparages modern research on the suspected relationship of the XYY chromosomal anomaly to violent and criminal behavior, research Gould refers to as a "reincarnation" of Lombroso. Gould writes, "The signs of innate criminality are no longer sought in stigmata of gross anatomy, but in twentieth- century criteria: genes and the fine structure of the brain" (p. 143). Apparently any research on the biological correlates of human behavior is deemed anathema by Gould.

Distorted and Misleading Information

It would be practically impossible for me to assess the accuracy of representation or the carefulness of interpretation of all the specific targets of Gould's multifarious critique. Frankly, I feel little inclination to comb the many archaic references on which most of Gould's debunking depends, especially because they are no longer of any concern to modern researchers in these fields. Who in 1982 is interested in debating precisely what was said by whom about the phlogiston theory in its heydey? I am able, however, to testify concerning a number of contemporary references, which are already at my fingertips.

In his references to my own work, Gould includes at least nine citations that involve more than just an expression of Gould's opinion; in these citations Gould purportedly paraphrases my views. Yet in eight of the nine cases, Gould's representation of these views is false, misleading, or grossly caricatured. Nonspecialists could have no way of knowing any of this without reading the cited sources. While ant author can occasionally make an inadvertent mistake in paraphrasing another, it appears Gould's paraphrases are consistently slanted to serve his own message. Through hyperbole and caricature he converts real issues into straw persons, which can be easily disproved.

Some examples are:

(1) Gould states that the normal variation within a population is a different biological phenomenon from the variation in average values between populations. (Actually, this may be or may not be true for any given trait; it is an empirical question.) Failure to recognize this distinction, Gould claims, is an error that occurs "over and over again "and is the "basis of Arthur Jensen's fallacy in asserting that average differences in IQ between American whites and blacks are largely inherited" (p. 127). The fact is, of course, that I have never "asserted" (Webster: " assert implies stating confidently without need for proof or regard for evidence") that IQ differences between any races are largely inherited. Nor have I ever claimed that the well-established heritability of individual differences in IQ within races proves the heritability of differences between races. To quote directly from some earlier writing (Jensen, 1970): "Group racial and social class differences are first of all individual differences [i.e., they are the statistical averages of individual measurements], but the causes of the group differences may not be the same as of the individual differences" (p.154, italics added). Whether the causes are or are not the same for any particular trait for any particular groups is a question open to rival hypotheses and empirical investigation. Such has always been my position, a position spelled out most recently in Chapter 6 of my book Straight Talk About Mental Tests (Jensen, 1981a).

(2) Gould claims that "Jensen recognizes that his hereditarian theory of IQ depends upon the validity of [Spearman's] q" (p.265), and that " ,Jensen has demonstrated by example that a reified Spearman's g is still the only promising justification for hereditarian theories of mean differences in IQ among human groups" (p. 320). This is simply nonsense. Neither I nor anyone else in behavioral genetics has ever claimed or believed any such thing. If the total variance in any battery of tests were treated by different methods of factor analysis, some methods yielding a large g, or general factor, and other methods spreading the variance over a number of group factors (or "primary mental abilities"), the total proportion of genetic variance in all of the factors would not be altered in the least. This is because heritability (i.e., the proportion of the total variance that is attributable to genetic factors) does not depend at all on the factor structure of the variables in question. (Similarly, either methodological preference whether for concentrating variance on g and possibly a few large group factors, or for distributing it more or less evenly over a larger number of "primaries," should not alter in the least the total amount of variance associated with race.) All this is not to say, however, that it would be scientifically trivial or theoretically uninteresting should it turn out that certain methods of factor analysis yield some factors that show high heritability while the remaining factors show virtually zero heritability. We already know that the g factor shows substantial heritability; and recently, Lloyd Humphreys (1981), in interpreting his analysis of twin and cross- twin correlations on the Project TALENT tests (a large battery of diverse aptitude and scholastic achievement tests), stated that "the genetic contribution to these cognitive tests, whatever its amount, was restricted to the general factor" (p. 99). This interpretation, if generally substantiated, would bear out Spearman's (1927) conjecture that g is the only heritable cognitive factor, while the various group factors (independent of g) arise from the investment of g in different contents of learning, as influenced by opportunity, interest, and reward. My own hunch is that a few of the largest and most stable group factors (e. g., verbal, numerical, memory, and spatial) as well as some components of musical and artistic aptitude, will probably also show some heritable variation independent of g.

(3) Gould claims that I have defended a g, or general intelligence, which is "reified as a measurable object" (p.318). Yet in the same chapter from which Gould is supposedly paraphrasing my views (Jensen, 1980a), I stated unequivocally that "[I]ntelligence is not an entity, but a theoretical construct.... The g factor may also be termed a theoretical construct, which is intended to explain an observable phenomenon, namely, the positive intercorrelation among all mental tests, regardless of their apparently great variety" (p. 249).