The Mismeasure of Man

by Stephen Jay Gould

  When Burt recycled these data in a 1912 paper for the Eugenics Review, he added additional “proof” with even smaller samples. He discussed Alfred Binet’s two daughters, noted that their father had been disinclined to connect physical signs with mental prowess, and pointed out that the blond, blue-eyed, large-headed daughter of Teutonic appearance was objective and forthright, while the darker daughter tended to be impractical and sentimental. Touché.

  Burt was no fool. I confess that I began reading him with the impression, nurtured by spectacular press reports of his fraudulent work, that he was simply a devious and foxy charlatan. To be sure, that he became and for complex reasons (see pp. 264–269). But as I read, I gained respect for Burt’s enormous erudition, for his remarkable sensitivity in most areas, and for the subtlety and complexity of his reasoning; I ended up liking most things about him in spite of myself. And yet, this assessment makes the extraordinary weakness of his reasoning about the innateness of intelligence all the more puzzling. If he had simply been a fool, then foolish arguments would denote consistency of character.

  My dictionary defines an idée fixe, or fixed idea, as “a persistent or obsessing idea, often delusional, from which a person cannot escape.” The innateness of intelligence was Burt’s idée fixe. When he turned his intellectual skills to other areas, he reasoned well, subtly, and often with great insight. When he considered the innateness of intelligence, blinders descended and his rational thinking evaporated before the hereditarian dogma that won his fame and eventually sealed his intellectual doom. It may be remarkable that Burt could operate with such a duality in styles of reasoning. But I find it much more remarkable that so many others believed Burt’s statements about intelligence when his arguments and data, all readily available in popular publications, contained such patent errors and specious claims. What does this teach us about shared dogma masquerading as objectivity?

  LATER ARGUMENTS

  Perhaps I have been unfair in choosing Burt’s earliest work for criticism. Perhaps the foolishness of youth soon yielded to mature wisdom and caution. Not at all; Burt was nothing if not ontogenetically consistent. The argument of 1909 never changed, never gained subtlety, and ended with manufactured support. The innateness of intelligence continued to function as dogma. Consider the primary argument of Burt’s most famous book, The Backward Child (1937), written at the height of his powers and before his descent into conscious fraud.

  Backwardness, Burt notes, is defined by achievement in school, not by tests of intelligence: backward children are more than a year behind in their schoolwork. Burt argues that environmental effects, if at all important, should have most impact upon children in this category (those much further behind in school are more clearly genetically impaired). Burt therefore undertook a statistical study of environment by correlating the percentage of backward children with measures of poverty in the boroughs of London. He calculated an impressive array of strong correlations: 0.73 with percentage of people below the poverty line, 0.89 with overcrowding, 0.68 with unemployment, and 0.93 with juvenile mortality. These data seem to provide a prima-facie case for a dominant environmental influence upon backwardness, but Burt demurs. There is another possibility. Perhaps the innately poorest stocks create and then gravitate to the worst boroughs, and degree of poverty is merely an imperfect measure of genetic worthlessness.

  Burt, guided by his idée fixe, opted for innate stupidity as the primary cause of poverty (1937, p. 105). He invoked IQ testing as his major argument. Most backward children score 1 to 2 standard deviations below the mean (70–85), within a range technically designated as “dull.” Since IQ records innate intelligence, most backward children perform poorly in school because they are dull, not (or only indirectly) because they are poor. Again, Burt rides his circle. He wishes to prove that deficiency of innate intelligence is the major cause of poor performance in school. He knows full well that the link between IQ score and innateness is an unresolved issue in intense debates about the meaning of IQ—and he admits in many places that the Stanford-Binet test is, at best, only an imperfect measure of innateness (e.g., 1921, p. 90). Yet, using the test scores as a guide, he concludes:

  In well over half the cases, the backwardness seems due chiefly to intrinsic mental factors; here, therefore, it is primary, innate, and to that extent beyond all hope of cure (1937, p. 110).

  Consider Burt’s curious definition of innate in this statement. An innate character, as inborn and, in Burt’s usage, inherited, forms part of an organism’s biological constitution. But the demonstration that a trait represents nature unaffected by nurture does not guarantee its ineluctable state. Burt inherited poor vision. No doctor ever rebuilt his eyes to an engineer’s paradigm of normal design, but Burt wore eyeglasses and the only clouding of his vision was conceptual.

  The Backward Child also abounds in tangential statements that record Burt’s hereditarian biases. He writes about an environmental handicap—recurrent catarrh among the poor—and discusses hereditary susceptibility (quite plausible) with an arresting quip for graphic emphasis:

  … exceptionally prevalent in those whose faces are marked by developmental defects—by the round receding forehead, the protruding muzzle, the short and upturned nose, the thickened lips, which combine to give to the slum child’s profile a negroid or almost simian outline.… “Apes that are hardly anthropoid” was the comment of one headmaster, who liked to sum up his cases in a phrase (1937, p. 186).

  He wonders about the intellectual achievement of Jews and attributes it, in part, to inherited myopia that keeps them off the playing fields and adapts them for poring over account books.

  Before the invention of spectacles, the Jew whose living depended upon his ability to keep accounts and read them, would have been incapacitated by the age of 50, had he possessed the usual tendency to hypermetropia: on the other hand (as I can personally testify) the myope … can dispense with glasses for near work without much loss of efficiency (1937, p. 219).

  BURT’S BLINDNESS

  The blinding power of Burt’s hereditarian biases can best be appreciated by studying his approach to subjects other than intelligence. For here he consistently showed a commendable caution. He recognized the complexity of causation and the subtle influence that environment can exert. He railed against simplistic assumptions and withheld judgment pending further evidence. Yet as soon as Burt returned to his favorite subject of intelligence, the blinders descended and the hereditarian catechism came forward again.

  Burt wrote with power and sensitivity about the debilitating effects of poor environments. He noted that 23 percent of the cockney youth he interviewed had never seen a field or a patch of grass, not “even in a Council park,” 64 percent had never seen a train, and 98 percent had never seen the sea. The following passage displays a measure of paternalistic condescension and stereotyping, but it also presents a powerful image of poverty in working-class homes, and its intellectual effect upon children (1937, p. 127).

  His mother and father know astonishingly little of any life except their own, and have neither the time nor the leisure, neither the ability nor the disposition, to impart what little they know. The mother’s conversation may be chiefly limited to the topics of cleaning, cooking, and scolding. The father, when not at work, may spend most of his time “round the corner” refreshing a worn-out body, or sitting by the fire with cap on and coat off, sucking his pipe in gloomy silence. The vocabulary that the child absorbs is restricted to a few hundred words, most of them inaccurate, uncouth, or mispronounced, and the rest unfit for reproduction in the schoolroom. In the home itself there is no literature that deserves the title; and the child’s whole universe is closed in and circumscribed by walls of brick and a pall of smoke. From one end of the year to the other, he may go no farther than the nearest shops or the neighborhood recreation ground. The country or the seaside are mere words to him, dimly suggesting some place to which cripples are sent after an accident, visualized perhaps in terms of some
photographic “souvenir from Southend” or some pictorial “memento from Margate,” all framed in shells, brought back by his parents on a bank-holiday trip a few weeks after their wedding.

  Burt appended this comment from a “burly bus conductor” to his description: “Book learning isn’t for kids that’ll have to earn their bread. It’s only for them as likes to give themselves the hairs of the ‘ighbrow.”

  Burt could apply what he understood so well to subjects other than intelligence. Consider his views on juvenile delinquency and left-handedness. Burt wrote extensively on the cause of delinquency and attributed it to complex interactions between children and their environment: “The problem never lies in the ‘problem child’ alone: it lies always in the relations between that child and his environment” (1940, p. 243). If poor behavioral performance merits such an assessment, why not say the same about poor intellectual performance? One might suspect that Burt relied again upon test scores, arguing that delinquents tested well and could not be misbehaving as a result of innate stupidity. But, in fact, delinquents often tested as badly as poor children regarded by Burt as innately deficient in intelligence. Yet Burt recognized that IQ scores of delinquents may not reflect inherited ability because they rebel against taking the tests:

  For what to them must seem nothing but a resuscitated school examination, delinquents, as a rule, feel little inclination and much distaste. From the outset they assume they are more likely to fail than succeed, more likely to be reproached than commended.… Unless, indeed, to circumvent their suspicion and secure their good-will special manoeuvers be tactfully tried, their apparent prowess with all such tests will fall much below their veritable powers.… In the causation of juvenile delinquency … the share contributed by mental defect has unquestionably been magnified by those who, trusting so exclusively to the Binet-Simon scale, have ignored the factors which depreciate its results (1921, pp. 189–190).

  But why not say that poverty often entails a similar disinclination and sense of defeat?

  Burt (1937, p. 270) regarded left-handedness as the “motor disability … which interferes most widely with the ordinary tasks of the classroom.” As chief psychologist of the London schools, he therefore devoted much study to its cause. Unburdened by a priori conviction in this case, he devised and attempted to test a wide range of potential environmental influences. He studied medieval and Renaissance paintings to determine if Mary usually carried the infant Jesus on her right hip. If so, babies would wrap their left arms about their mother’s neck, leaving their right hand free for more dextrous (literally right-handed) motion. He wondered if greater frequency of right-handedness might record the asymmetry of internal organs and the need for protection imposed by our habits. If heart and stomach lie to the left of the midline, then a warrior or worker would naturally turn his left side away from potential danger, “trust to the more solid support of the right side of the trunk, and so use his right hand and arm for wielding heavy instruments and weapons” (1937, p. 270). In the end, Burt opted for caution and concluded that he could not tell:

  I should in the last resort contend that probably all forms of left-handedness are only indirectly hereditary: postnatal influence seems always to enter in.… I must accordingly repeat that, here as elsewhere in psychology, our present knowledge is far too meager to allow us to declare with any assurance what is inborn and what is not (1937, pp. 303–304).

  Substitute “intelligence” for “left-handedness” and the statement is a model of judicious inference. In fact, left-handedness is more clearly an entity than intelligence, and probably more subject to definite and specifiable hereditary influence. Yet here, where his case for innateness was better, Burt tested all the environmental influences—some rather farfetched—that he could devise, and finally declared the subject too complex for resolution.

  BURT’S POLITICAL USE OF INNATENESS

  Burt extended his belief in the innateness of individual intelligence to only one aspect of average differences between groups. He did not feel (1912) that races varied much in inherited intelligence, and he argued (1921, p. 197) that the different behaviors of boys and girls can be traced largely to parental treatment. But differences in social class, the wit of the successful and dullness of the poor, are reflections of inherited ability. If race is America’s primary social problem, then class has been Britain’s corresponding concern.

  In his watershed* paper (1943) on “ability and income,” Burt concludes that “the wide inequality in personal income is largely, though not entirely, an indirect effect of the wide inequality in innate intelligence.” The data “do not support the view (still held by many educational and social reformers) that the apparent inequality in intelligence of children and adults is in the main an indirect consequence of inequality in economic conditions” (1943, p-141).

  Burt often denied that he wished to limit opportunities for achievement by regarding tests as measures of innate intelligence. He argued, on the contrary, that tests could identify those few individuals in the lower classes whose high innate intelligence would not otherwise be recognized under a veneer of environmental disadvantage. For “among nations, success in the struggle for survival is bound to depend more and more on the achievements of a small handful of individuals who are endowed by nature with outstanding gifts of ability and character” (1959, p. 31). These people must be identified and nurtured to compensate for “the comparative ineptitude of the general public” (1959, p. 31). They must be encouraged and rewarded, for the rise and fall of a nation does not depend upon genes peculiar to an entire race, but upon “changes in the relative fertility of its leading members or its leading classes” (1962, p. 49).

  Tests may have been the vehicle by which a few children escaped from the strictures of a fairly inflexible class structure. But what was their effect on the vast majority of lower-class children whom Burt unfairly branded as unable, by inheritance, ever to develop much intelligence—and therefore undeserving, by reason, of higher social standing?

  Any recent attempt to base our educational policy for the future on the assumption that there are no real differences, or at any rate no important differences, between the average intelligence of the different social classes, is not only bound to fail; it is likely to be fraught with disastrous consequences for the welfare of the nation as a whole, and at the same time to result in needless disappointments for the pupils concerned. The facts of genetic inequality, whether or not they conform to our personal wishes and ideals, are something that we cannot escape (1959, p. 28).… A definite limit to what children can achieve is inexorably set by the limitations of their innate capacity (1969).

  Burt’s extension of Spearman’s theory

  Cyril Burt may be known best to the public as a hereditarian in the field of mental testing, but his reputation as a theoretical psychologist rested primarily upon his work in factor analysis. He did not invent the technique, as he later claimed; but he was Spearman’s successor, both literally and figuratively, and he became the leading British factorist of his generation.

  Burt’s genuine achievements in factor analysis were substantial. His complex and densely reasoned book on the subject (1940) was the crowning achievement of Spearman’s school. Burt wrote that it “may prove to be a more lasting contribution to psychology than anything else I have yet written” (letter to his sister quoted in Hearnshaw, 1979, p. 154). Burt also pioneered (though he did not invent) two important extensions of Spearman’s approach—an inverted technique (discussed on pp. 322–323) that Burt called “correlation between persons” (now known to aficionados as “Q-mode factor analysis”), and an expansion of Spearman’s two-factor theory to add “group factors” at a level between g and s.

  Burt toed Spearman’s line in his first paper of 1909. Spearman had insisted that each test recorded only two properties of mind—a general factor common to all tests and a specific factor peculiar to that test alone. He denied that clusters of tests showed any significant tendency to form �
�group factors” between his two levels—that is, he found no evidence for the “faculties” of an older psychology, no clusters representing verbal, spatial, or arithmetic ability, for example. In his 1909 paper, Burt did note a “discernible, but small” tendency for grouping in allied tests. But he proclaimed it weak enough to ignore (“vanishingly minute” in his words), and argued that his results “confirm and extend” Spearman’s theory.

  But Burt, unlike Spearman, was a practitioner of testing (responsible for all of London’s schools). Further studies in factor analysis continued to distinguish group factors, though they were always subsidiary to g. As a practical matter for guidance of pupils, Burt realized that he could not ignore the group factors. With a purely Spearmanian approach, what could a pupil be told except that he was generally smart or dumb? Pupils had to be guided toward professions by identifying strengths and weaknesses in more specific areas.

  By the time Burt did his major work in factor analysis, Spearman’s cumbersome method of tetrad differences had been replaced by the principal components approach outlined on pp. 275–280. Burt identified group factors by studying the projection of individual tests upon the second and subsequent principal components. Consider Fig. 6.6: In a matrix of positive correlation coefficients, vectors representing individual tests are all clustered together. The first principal component, Spearman’s g runs through the middle of the cluster and resolves more information than any other axis could. Burt recognized that no consistent patterns would be found on subsequent axes if Spearman’s two-factor theory held—for the vectors would not form subclusters if their only common variance had already been accounted for by g. But if the vectors form subclusters representing more specialized abilities, then the first principal component must run between the sub-clusters if it is to be the best average fit to all vectors. Since the second principal component is perpendicular to the first, some subclusters must project positively upon it and others negatively (as Fig. 6.6 shows with its negative projections for verbal tests and positive projections for arithmetic tests). Burt called these axes bipolar factors, because they included clusters of positive and negative projections. He identified as group factors the clusters of positive and negative projections themselves.