The reaction to Jensen’s article was immediate and violent. From 1969 through the mid-1970s, dozens of books and hundreds of articles appeared denouncing the use of IQ tests and arguing that mental abilities are determined by environment, with the genes playing a minor role and race none at all. Jensen’s name became synonymous with a constellation of hateful ways of thinking. “It perhaps is impossible to exaggerate the importance of the Jensen disgrace,” wrote Jerry Hirsch, a psychologist specializing in the genetics of animal behavior who was among Jensen’s more vehement critics. “It has permeated both science and the universities and hoodwinked large segments of government and society. Like Vietnam and Watergate, it is a contemporary symptom of serious affliction.”22 The title of Hirsch’s article was “The Bankruptcy of ‘Science’ Without Scholarship.” During the first few years after the Harvard Educational Review article was published, Jensen could appear in no public forum in the United States without triggering something perilously close to a riot.
The uproar was exacerbated by William Shockley, who had won the Nobel Prize in physics for his contributions to the invention of the transistor but had turned his attention to human variation toward the end of his career. As eccentric as he was brilliant, he often recalled the eugenicists of the early decades of the century. He proposed, as a “thought exercise,” a scheme for paying people with low IQs to be sterilized.23 He supported (and contributed to) a sperm bank for geniuses. He seemed to relish expressing sensitive scientific findings in a way that would outrage or disturb as many people as possible. Jensen and Shockley, utterly unlike as they were in most respects, soon came to be classed together as a pair of racist intellectual cranks.
Then one of us, Richard Herrnstein, an experimental psychologist at Harvard, strayed into forbidden territory with an article in the September 1971 Atlantic Monthly.24 Herrnstein barely mentioned race, but he did talk about heritability of IQ. His proposition, put in the form of a syllogism, was that because IQ is substantially heritable, because economic success in life depends in part on the talents measured by IQ tests, and because social standing depends in part on economic success, it follows that social standing is bound to be based to some extent on inherited differences. By 1971, this had become a controversial thing to say. In media accounts of intelligence, the names Jensen, Shockley, and Herrnstein became roughly interchangeable.
That same year, 1971, the U.S. Supreme Court outlawed the use of standardized ability tests by employers unless they had a “manifest relationship” to the specific job in question because, the Supreme Court held, standardized tests acted as “built-in headwinds” for minority groups, even in the absence of discriminatory intent.25 A year later, the National Education Association called upon the nation’s schools to impose a moratorium on all standardized intelligence testing, hypothesizing that “a third or more of American citizens are intellectually folded, mutilated or spindled before they have a chance to get through elementary school because of linguistically or culturally biased standardized tests.”26 A movement that had begun in the 1960s gained momentum in the early 1970s, as major school systems throughout the country, including those of Chicago, New York, and Los Angeles, limited or banned the use of group-administered standardized tests in public schools. A number of colleges announced that they would no longer require the Scholastic Aptitude Test as part of the admissions process. The legal movement against tests reached its apogee in 1978 in the case of Larry P. Judge Robert Peckham of the U.S. District Court in San Francisco ruled that it was unconstitutional to use IQ tests for placement of children in classes for the educably mentally retarded if the use of those tests resulted in placement of “grossly disproportionate” numbers of black children.27
Meanwhile, the intellectual debate had taken a new and personalized turn. Those who claimed that intelligence was substantially inherited were not just wrong, the critics now discovered, they were charlatans as well. Leon Kamin, a psychologist then at Princeton, opened this phase of the debate with a 1974 book, The Science and Politics of IQ. “Patriotism, we have been told, is the last refuge of scoundrels,” Kamin wrote in the opening pages. “Psychologists and biologists might consider the possibility that heritability is the first.”28 Kamin went on to charge that mental testing and belief in the heritability of IQ in particular had been fostered by people with right-wing political views and racist social views. They had engaged in pseudoscience, he wrote, suppressing the data they did not like and exaggerating the data that agreed with their preconceptions. Examined carefully, the case for the heritability of IQ was nil, concluded Kamin.
In 1976, a British journalist, Oliver Gillie, published an article in the London Sunday Times that seemed to confirm Kamin’s thesis with a sensational revelation: The recently deceased Cyril Burt, Britain’s most eminent psychometrician, author of the largest and most famous study of the intelligence of identical twins who grew up apart, was charged with fraud.29 He had made up data, fudged his results, and invented coauthors, the Sunday Times declared. The subsequent scandal was as big as the Piltdown Man hoax. Cyril Burt had not been just another researcher but one of the giants of twentieth-century psychology. Nor could his colleagues find a ready defense (the defense came later, as described in the box). They protested that the revelations did not compromise the great bulk of the work that bore on the issue of heritability, but their defenses sounded feeble in the light of the suspicions that had preceded Burt’s exposure.
For the public observing the uproar in the academy from the sidelines, the capstone of the assault on the integrity of the discipline occurred in 1981 when Harvard paleobiologist Stephen Jay Gould, author of several popular books on biology, published The Mismeasure of Man.32 Gould examined the history of intelligence testing, found that it was peopled by charlatans, racists, and self-deluded fools, and concluded that “determinist arguments for ranking people according to a single scale of intelligence, no matter how numerically sophisticated, have recorded little more than social prejudice.”33 The Mismeasure of Man became a best-seller and won the National Book Critics Circle Award.
The Burt Affair
It would be more than a decade before the Burt affair was subjected to detailed reexamination. In 1989 and 1991, two accounts of the Burt allegations, by psychologist Robert Joynson and sociologist Ronald Fletcher, written independently, concluded that the attacks against Burt had been motivated by a mixture of professional and ideological antagonism and that no credible case of data falsification or fictitious research or researchers had ever been presented.30 Both authors also concluded that some of Burt’s leading critics were aware that their accusations were inaccurate even at the time they made them. An ironic afterword centers on Burt’s claim that the correlation between the IQs of identical twins reared apart is +.77. A correlation this large almost irrefutably supports a large genetic influence on IQ. Since the attacks on Burt began, it had been savagely derided as fraudulent, the product of Burt’s fiddling with the data to make his case. In 1990, the Minnesota twin study, accepted by most scholars as a model of its kind, produced its most detailed estimates of the correlation of IQ between identical twins reared apart. The procedure that most closely paralleled Burt’s yielded a correlation of +.78.31
Gould and his allies had won the visible battle. By the early 1980s, a new received wisdom about intelligence had been formed that went roughly as follows:
Intelligence is a bankrupt concept. Whatever it might mean—and nobody really knows even how to define it—intelligence is so ephemeral that no one can measure it accurately. IQ tests are, of course, culturally biased, and so are all the other “aptitude” tests, such as the SAT. To the extent that tests such as IQ and SAT measure anything, it certainly is not an innate “intelligence.” IQ scores are not constant; they often change significantly over an individual’s life span. The scores of entire populations can be expected to change over time—look at the Jews, who early in the twentieth century scored below average on IQ scores and now score well above
the average. Furthermore, the tests are nearly useless as tools, as confirmed by the well-documented fact that such tests do not predict anything except success in school. Earnings, occupation, productivity—all the important measures of success—are unrelated to the test scores. All that tests really accomplish is to label youngsters, stigmatizing the ones who do not do well and creating a self fulfilling prophecy that injures the socioeconomically disadvantaged in general and blacks in particular.
INTELLIGENCE REDUX
As far as public discussion is concerned, this collection of beliefs, with some variations, remains the state of wisdom about cognitive abilities and IQ tests. It bears almost no relation to the current state of knowledge among scholars in the field, however, and therein lies a tale. The dialogue about testing has been conducted at two levels during the last two decades—the visible one played out in the press and the subterranean one played out in the technical journals and books.
The case of Arthur Jensen is illustrative. To the public, he surfaced briefly, published an article that was discredited, and fell back into obscurity. Within the world of psychometrics, however, he continued to be one of the profession’s most prolific scholars, respected for his meticulous research by colleagues of every theoretical stripe. Jensen had not recanted. He continued to build on the same empirical findings that had gotten him into such trouble in the 1960s, but primarily in technical publications, where no one outside the profession had to notice. The same thing was happening throughout psychometrics. In the 1970s, scholars observed that colleagues who tried to say publicly that IQ tests had merit, or that intelligence was substantially inherited, or even that intelligence existed as a definable and measurable human quality, paid too high a price. Their careers, family lives, relationships with colleagues, and even physical safety could be jeopardized by speaking out. Why speak out when there was no compelling reason to do so? Research on cognitive abilities continued to flourish, but only in the sanctuary of the ivory tower.
In this cloistered environment, the continuing debate about intelligence was conducted much as debates are conducted within any other academic discipline. The public controversy had surfaced some genuine issues, and the competing parties set about trying to resolve them. Controversial hypotheses were put to the test. Sometimes they were confirmed, sometimes rejected. Often they led to new questions, which were then explored. Substantial progress was made. Many of the issues that created such a public furor in the 1970s were resolved, and the study of cognitive abilities went on to explore new areas.
This is not to say that controversy has ended, only that the controversy within the professional intelligence testing community is much different from that outside it. The issues that seem most salient in articles in the popular press (Isn’t intelligence determined mostly by environment? Aren’t the tests useless because they’re biased?) are not major topics of debate within the profession. On many of the publicly discussed questions, a scholarly consensus has been reached.34 Rather, the contending parties within the professional community divide along other lines. By the early 1990s, they could be roughly divided into three factions for our purposes: the classicists, the revisionists, and the radicals.
The Classicists: Intelligence as a Structure
The classicists work within the tradition begun by Spearman, seeking to identify the components of intelligence much as physicists seek to identify the structure of the atom. As of the 1990s, the classicists are for practical purposes unanimous in accepting that g sits at the center of the structure in a dominating position—not just as an artifact of statistical manipulation but as an expression of a core human mental ability much like the ability Spearman identified at the turn of the century. In their view, g is one of the most thoroughly demonstrated entities in the behavioral sciences and one of the most powerful for understanding socially significant human variation.
The classicists took a long time to reach this level of consensus. The ink on Spearman’s first article on the topic in 1904 was barely dry before others were arguing that intellectual ability could not be adequately captured by g or by any other unitary quantity—and understandably so, for common sense rebels against the idea that something so important about people as their intellects can be captured even roughly by variations in a single quantity. Many of the famous names in the history of psychometrics challenged the reality of g, starting with Galton’s most eminent early disciple, Karl Pearson, and continuing with many other creative and influential psychometricians.
In diverse ways, they sought the grail of a set of primary and mutually independent mental abilities. For Spearman, there was just one such primary ability, g. For Raymond Cattell, there are two kinds of g, crystallized and fluid, with crystallized g being general intelligence transformed into the skills of one’s own culture, and fluid g being the all-purpose intellectual capacity from which the crystallized skills are formed. In Louis Thurstone’s theory of intelligence, there are a half-dozen or so primary mental abilities, such as verbal, quantitative, spatial, and the like. In Philip Vernon’s theory, intellectual capacities are arranged in a hierarchy with g at its apex; in Joy Guilford’s, the structure of intellect is refined into 120 or more intellectual components. The theoretical alternatives to unitary, general intelligence have come in many sizes, shapes, and degrees of plausibility.
Many of these efforts proved to have lasting value. For example, Cattell’s distinction between fluid and crystallized intelligence remains a useful conceptual contrast, just as other work has done much to clarify what lies in the domain of specific abilities that g cannot account for. But no one has been able to devise a set of tests that do not reveal a large general factor of intellectual ability—in other words, something very like Spearman’s g. Furthermore, the classicists point out, the best standardized tests, such as a modern IQ test, do a reasonably good job of measuring g. When properly administered, the tests are not measurably biased against socioeconomic, ethnic, or racial subgroups. They predict a wide variety of socially important outcomes.
This is not the same as saying that the classicists are satisfied with their understanding of intelligence, g is a statistical entity, and current research is probing the underlying neurologic basis for it. Arthur Jensen, the archetypal classicist, has been active in this effort for the last decade, returning to Galton’s intuition that performance on elementary cognitive tasks, such as reaction time in recognizing simple patterns of lights and shapes, provides an entry point into understanding the physiology of g.
The Revisionists: Intelligence as Information Processing
A theory of intelligence need not be structural. The emphasis may be on process rather than on structure. In other words, it may try to figure out what a person is doing when exercising his or her intelligence, rather than what elements of intelligence are put together. The great Swiss psychologist, Jean Piaget, started his career in Alfred Binet’s laboratory trying to adapt Cyril Burt’s intelligence tests for Parisian children. Piaget discovered quickly that he was less interested in how well the children did than in what errors they made.35 Errors revealed what the underlying processes of thought must have been, Piaget believed. It was the processes of intelligence that fascinated him during his long and illustrious career, which led in time to his theory of the stages of cognitive development.
Starting in the 1960s, research on human cognition became the preoccupation of experimental psychologists, displacing the animal learning experiments of the earlier period. It was inevitable that the new experimentalists would turn to the study of human intelligence in natural settings. John B. Carroll and Earl B. Hunt led the way from the cognition laboratory to the study of human intelligence in everyday life. Today Yale psychologist Robert Sternberg is among the leaders of this development.
The revisionists share much with the classicists. They accept that a general mental ability much like Spearman’s g has to be incorporated into any theory of the structure of intelligence, although they would not agree that it ac
counts for as much of the intellectual variation among people as many classicists claim. They use many of the same statistical tools as the classicists and are prepared to subject their work to the same standards of rigor. Where they differ with the classicists, however, is their attitude toward intellectual structure and the tests used to measure it.
Yes, the revisionists argue, human intelligence has a structure, but is it worth investing all that effort in discovering what it is? The preoccupation with structure has engendered preoccupation with summary scores, the revisionists say. That, after all, is what an IQ score represents: a composite of scores that individually measure quite distinct intellectual processes. “Of course,” Sternberg writes, “a tester can always average over multiple scores. But are such averages revealing, or do they camouflage more than they reveal? If a person is a wonderful visualizer but can barely compose a sentence, and another person can write glowing prose but cannot begin to visualize the simplest spatial images, what do you really learn about these two people if they are reported to have the same IQ?”36
By focusing on processes, the revisionists argue, they are working richer veins than are those who search for static structure. What really counts about intelligence are the ways in which people process the information they receive. What problem-solving mechanisms do they employ? How do they trade off speed and accuracy? How do they combine different problem-solving resources into a strategy? Sternberg has fashioned his own thinking on this topic into what he calls a “triarchy of intelligence,” or “three aspects of human information processing,”37
The first part of Sternberg’s triarchy attempts to describe the internal architecture of intellectual functioning, the means by which humans translate sensory inputs into mental representations, allocate mental resources, infer conclusions from raw material, and acquire skills. This architectural component of Sternberg’s theory bears a family resemblance to the classicists’ view of the dimensions of intelligence, but it emphasizes process over structure.
The Bell Curve: Intelligence and Class Structure in American Life Page 4
