Arthur Jensen - Criticism

Criticism

Melvin Konner wrote in the notes to his book The Tangled Wing: Biological Constraints on the Human Spirit:

Statements made by Arthur Jensen, William Shockley, and other investigators in the late 1960s and early 1970s about race and IQ or social class and IQ rapidly passed into currency in policy discussions. Many of these statements were proved wrong, but they had already influenced some policymakers, and that influence is very difficult to recant.

Many studies that purport to be both science-based and attempt to influence public policy have been accused of scientific racism. Konner wrote:

What of the latest currents of thought? Are they likely to lead to, or at least encourage, further distortions of social policy? The indications are not all encouraging. Richard Herrnstein and Charles Murray published a book in 1994 clearly directed at policy, just as Jensen and others had in the 1960s and 1970s. The Bell Curve: Intelligence and Class Structure in American Life (New York: Free Press 1994) teamed a psychologist with a conservative policy advocate to try to prove that both the class structure and the racial divide in the United States result from genetically determined differences in intelligence and ability. Their general assertions about genes and IQ were not very controversial, but their speculations on race were something else again.

By 1994, the time of The Bell Curve's publishing, Jensen had received $1.1 million from the Pioneer Fund, an organization frequently described as racist and "white supremacist" in nature. The fund contributed a total of $3.5 million to researchers cited in The Bell Curve's most controversial chapter "that suggests some races are naturally smarter than others" with Jensen's works being cited twenty-three times in the book's bibliography.

Lisa Suzuki and Joshua Aronson of New York University claimed in 2005 that Jensen has largely ignored evidence that fails to support his position that IQ test score gaps represent a genetic racial hierarchy unwaveringly for over 30 years.

Paleontologist and evolutionary biologist Stephen Jay Gould, attacked Jensen's work in his 1981 book The Mismeasure of Man. Gould writes that Jensen misapplies the concept of "heritability", which is defined as a measure of the variation of a trait due to inheritance within a population (Gould 1981: 127; 156-157). According to Gould, Jensen uses heritability to measure differences between populations. Gould also disagrees with Jensen's belief that IQ tests measure a real variable, g, or "the general factor common to a large number of cognitive abilities" which can be measured along a unilinear scale.

This is a claim most closely identified with Charles Spearman. According to Gould, Jensen misunderstood the research of L. L. Thurstone to ultimately support this claim; Gould, however, argues that Thurstone's factor analysis of intelligence revealed g to be an illusion (1981: 159; 13-314). Gould criticizes Jensen's sources including his use of Catharine Cox's 1926 Genetic Studies of Genius, which examines historiometrically the IQs of historic intellectuals after their deaths (Gould 1981: 153-154).

In 1980 Jensen published a detailed book in defense of the tests used to measure mental abilities, entitled Bias in Mental Testing. Reviewing this book, psychologist Kenneth Kaye endorsed Jensen's distinction between bias and discrimination. The purpose of tests is to discriminate (that is, reveal actual differences) on the basis of ability; bias constitutes error. Jensen defined any test as biased for a particular group if that group differs significantly from the majority group in the slopes, intercepts, or standard error of the estimates of their regression lines. Most studies found no difference in the regression lines between black and white groups, but those differences that had been found to be biased had overpredicted rather than underpredicted the minority group's performance (for example, grades in Officer Candidate courses). Jensen's conclusion:

Until we find out what the relevant psychological predictors are for which racial classification per se is merely a 'stand-in' variable, we have no choice but to include race (or other group membership) as a predictive variable along with the test scores or other predictive measures. On the other hand, if the overprediction of the minority group's criterion performance is not too extreme, it may seem reasonable to many to leave it uncorrected, thereby giving the benefit of the slight predictive bias to the presumably disadvantaged group.

Pointing out that "many of Jensen's opponents allowed their scientific conclusions to be far more biased by their political views than he did, Kaye quoted 18th-century David Hume: "There is no Method of Reasoning more Common, and yet none more blameable, than in philosophical Debates, to endeavor the Refutation of any Hypothesis, by a Pretext of its dangerous Consequences to Religion and Morality."

In a 1982 review of The Mismeasure of Man, Jensen gives point-by-point rebuttals to much of Gould's critique, including Gould's treatment of heritability, the "reification" of g, and the use of Thurstone's analysis. Gould responded to Jensen's rebuttals in a revised edition of the book, published in 1996.