The history of the race and intelligence controversy concerns the historical development of a debate about possible explanations of group differences encountered in the study of race and intelligence. Since the beginning of IQ testing around the time of World War I, there have been observed differences between the average scores of different population groups, and there have been debates over whether this is mainly due to environmental and cultural factors, or mainly due to some as yet undiscovered genetic factor, or whether such a dichotomy between environmental and genetic factors is the appropriate framing of the debate. Today, the scientific consensus is that genetics does not explain differences in IQ test performance between racial groups. Pseudoscientific claims of inherent differences in intelligence between races have played a central role in the history of scientific racism. In the late 19th and early 20th century, group differences in intelligence were often assumed to be racial in nature. Apart from intelligence tests, research relied on measurements such as brain size or reaction times. By the mid-1940s most psychologists had adopted the view that environmental and cultural factors predominated. In the mid-1960s, physicist William Shockley sparked controversy by claiming there might be genetic reasons that black people in the United States tended to score lower on IQ tests than white people. In 1969 the educational psychologist Arthur Jensen published a long article with the suggestion that compensatory education could have failed to that date because of genetic group differences. A similar debate among academics followed the publication in 1994 of The Bell Curve by Richard Herrnstein and Charles Murray. Their book prompted a renewal of debate on the issue and the publication of several interdisciplinary books on the issue. A 1995 report from the American Psychological Association responded to the controversy, finding no conclusive explanation for the observed differences between average IQ scores of racial groups. More recent work by James Flynn, William Dickens and Richard Nisbett has highlighted the narrowing gap between racial groups in IQ test performance, along with other corroborating evidence that environmental rather than genetic factors are the cause of these differences.
History
Early history
In the 18th century, debates surrounding the institution of slavery in the Americas hinged on the question of whether innate differences in intellectual capacity existed between races, in particular between black people and white people. Some European philosophers and scientists, such as Voltaire, David Hume, Immanuel Kant, and Carl Linnaeus, either argued or simply presupposed that white people were intellectually superior. Others, such as Henri Gregoire and Constantin de Chasseboeuf, argued that ancient Egypt had been a black civilization, and that it was therefore black people who had "discovered the elements of science and art, at a time when all other men were barbarous." During the French Revolution, Jean-Baptiste Belley, an elected member of the National Convention and the Council of Five Hundred who had been born in Senegal, became a leading proponent of the idea of racial intellectual equality. In 1785, Thomas Jefferson wrote of his "suspicion" that black people were "inferior to... whites in endowments both of body and mind." However, in 1791, after corresponding with the free African-American polymath Benjamin Banneker, Jefferson wrote that he hoped to see such "instances of moral eminence so multiplied as to prove that the want of talents observed in them is merely the effect of their degraded condition, and not proceeding from any difference in the structure of the parts on which intellect depends."
During the 19th and early 20th centuries, the idea that there are differences in the brain structures and brain sizes of different races, and that this implied differences in intelligence, was a popular topic, inspiring numerous typological studies. Samuel Morton's Crania Americana, published in 1839, was one such study, arguing that intelligence was correlated with brain size and that both of these metrics varied between racial groups.
Through the publication of his book Hereditary Genius in 1869, polymath Francis Galton spurred interest in the study of mental abilities, particularly as they relate to heredity and eugenics. Lacking the means to directly measure intellectual ability, Galton attempted to estimate the intelligence of various racial and ethnic groups. He based his estimations on observations from his and others' travels, the number and quality of intellectual achievements of different groups, and on the percentage of "eminent men" in each of these groups. Galton hypothesized that intelligence was normally distributed in all racial and ethnic groups, and that the means of these distributions varied between the groups. In Galton's estimation, ancient Attic Greeks had been the people with the highest incidence of genius intelligence, followed by contemporary Englishmen, with black Africans at a lower level, and Australian Aboriginals lower still. He did not specifically study Jews, but remarked that "they appear to be rich in families of high intellectual breeds".
Meanwhile, the American abolitionist and escaped slave Frederick Douglass had gained fame for his oratory and incisive writings, despite having learned to read as a child largely through surreptitious observation. Accordingly, he had been described by abolitionists as a living counter-example to slaveholders' arguments that people of African descent lacked the intellectual capacity to function as independent American citizens. His eloquence was so notable that some found it hard to believe he had once been a slave. In the later years of his life, one newspaper described him as "a bright example of the capability of the colored race, even under the blighting influence of slavery, from which he emerged and became one of the distinguished citizens of the country." Other abolitionists of the 19th century continued to advance the theme of ancient Egypt as a black civilization as an argument against racism. On this basis, scholar and diplomat Alexander Hill Everett argued in his 1927 book America: "With regard to the intellectual capabilities of the African race, it may be observed that Africa was once the nursery of science and literature, and it was from thence that they were disseminated among the Greeks and Romans." Similarly, the philosopher John Stuart Mill posited in his 1849 essay "On the Negro Question" that "it was from Negroes, therefore, that the Greeks learnt their first lessons in civilization." In 1895, R. Meade Bache of the University of Pennsylvania published an article in Psychological Review claiming that reaction time increases with evolution. Bache supported this claim with data showing slower reaction times among White Americans when compared with those of Native Americans and African Americans, with Native Americans having the quickest reaction time. He hypothesized that the slow reaction time of White Americans was to be explained by their possessing more contemplative brains which did not function well on tasks requiring automatic responses. This was one of the first examples of modern scientific racism, in which a veneer of science was used to bolster belief in the superiority of a particular race.
1900–1920 In 1903, the pioneering African-American sociologist W. E. B. Du Bois published his landmark collection of essays The Souls of Black Folk in defense of the inherent mental capacity and equal humanity of black people. According to Manning Marable, this book "helped to create the intellectual argument for the black freedom struggle in the twentieth century. 'Souls' justified the pursuit of higher education for Negroes and thus contributed to the rise of the black middle class." In contrast to other civil rights leaders like Booker T. Washington, who advocated for incremental progress and vocational education as a way for black Americans to demonstrate the virtues of "industry, thrift, intelligence and property" to the white majority, Du Bois advocated for black schools to focus more on liberal arts and academic curriculum (including the classics, arts, and humanities), because liberal arts were required to develop a leadership elite. Du Bois argued that black populations just as much as white ones naturally give rise to what he termed a "talented tenth" of intellectually gifted individuals.
At the same time, the discourse of scientific racism was accelerating. In 1910 the sociologist Howard W. Odum published his book Mental and Social Traits of the Negro, which described African-American students as "lacking in filial affection, strong migratory instincts, and tendencies; little sense of veneration, integrity or honor; shiftless, indolent, untidy, improvident, extravagant, lazy, lacking in persistence and initiative and unwilling to work continuously at details. Indeed, experience with the Negro in classrooms indicates that it is impossible to get the child to do anything with continued accuracy, and similarly in industrial pursuits, the Negro shows a woeful lack of power of sustained activity and constructive conduct." As the historian of psychology Ludy T. Benjamin explains, "with such prejudicial beliefs masquerading as facts," it was at this time that educational segregation on the basis of race was imposed in some states. The first practical intelligence test was developed between 1905 and 1908 by Alfred Binet in France for school placement of children. Binet warned that results from his test should not be assumed to measure innate intelligence or used to label individuals permanently. In 1916 Binet's test was translated into English and revised by Lewis Terman (who introduced IQ scoring for the test results) and published under the name Stanford–Binet Intelligence Scales. Terman wrote that Mexican-Americans, African-Americans, and Native Americans have a mental "dullness [that] seems to be racial, or at least inherent in the family stocks from which they come." He also argued for a higher frequency of so-called "morons" among non-white American racial groups, and concluded that there were "enormously significant racial differences in general intelligence" which could not be remedied by education.
In 1916 a team of psychologists, led by Robert Yerkes and including Terman and Henry H. Goddard, adapted the Stanford-Binet tests as multiple-choice group tests for use by the US army. In 1919, Yerkes devised a version of this test for civilians, the National Intelligence Test, which was used in all levels of education and in business. Like Terman, Goddard had argued in his book, Feeble-mindedness: Its Causes and Consequences (1914), that "feeble-mindedness" was hereditary; and in 1920 Yerkes in his book with Yoakum on the Army Mental Tests described how they "were originally intended, and are now definitely known, to measure native intellectual ability". Both Goddard and Terman argued that the feeble-minded should not be allowed to reproduce. In the US, however, independently and prior to the IQ tests, there had been political pressure for such eugenic policies to be enforced by sterilization; consequently, IQ tests became used as justification for sterilizing intellectually disabled people. Early IQ tests were also used to argue for limits to immigration to the US. Already in 1917, Goddard reported on the low IQ scores of new arrivals at Ellis Island. Yerkes argued on the basis of his army test scores that there were consistently lower IQ levels among those from Southern and Eastern Europe, which he suggested could lead to a decline in the average IQ of Americans if immigration from these regions were not limited.
1920–1960 In the 1920s, psychologists started questioning underlying assumptions of racial differences in intelligence; although not discounting them, the possibility was considered that they were on a smaller scale than previously supposed and also due to factors other than heredity. In 1924, Floyd Allport wrote in his book Social Psychology that the French sociologist Gustave Le Bon was incorrect in asserting "a gap between inferior and superior species", and pointed to "social inheritance" and "environmental factors" as accounting for differences. Nevertheless, he suggested that: "the intelligence of the white race is of a more versatile and complex order than that of the black race. It is probably superior to that of the red or yellow races." In 1923, in his book A study of American intelligence, Carl Brigham wrote that on the basis of the Yerkes army tests: "The decline in intelligence is due to two factors, the change in races migrating to this country, and to the additional factor of sending lower and lower representatives of each race." He concluded that: "The steps that should be taken to preserve or increase our present mental capacity must, of course, be dictated by science and not by political expediency. Immigration should not only be restrictive, but highly selective." The Immigration Act of 1924 put these recommendations into practice, introducing quotas based on the 1890 census, prior to the waves of immigration from Poland and Italy. While Gould and Kamin argued that the psychometric claims of Nordic superiority had a profound influence on the institutionalization of the 1924 immigration law, other scholars have argued that "the eventual passage of the 'racist' immigration law of 1924 was not crucially affected by the contributions of Yerkes or other psychologists".
In 1929, Robert Woodworth, in his textbook Psychology: A Study of Mental Life, made no claims about innate differences in intelligence between races, pointing instead to environmental and cultural factors. He considered it advisable to "suspend judgment and keep our eyes open from year to year for fresh and more conclusive evidence that will probably be discovered". In the 1930s, the English psychologist Raymond Cattell wrote three tracts, Psychology and Social Progress (1933), The Fight for Our National Intelligence (1937) and Psychology and the Religious Quest (1938). The second was published by the Eugenics Society, of which he had been a research fellow; it predicted the disastrous consequences of not stopping the decline in the average intelligence in Britain by one point per decade. In 1933, Cattell wrote that, of all the European races, the "Nordic race was the most evolved in intelligence and stability of temperament". He argued for "no mixture of bloods between racial groups" because "the resulting re-shuffling of impulses and psychic units throws together in each individual a number of forces which may be incompatible". He rationalised the "hatred and abhorrence ... for the Jewish practice of living in other nations instead of forming an independent self-sustained group of their own", referring to them as "intruders" with a "crafty spirit of calculation". He recommended a rigid division of races, referring to those suggesting that individuals be judged on their merits, irrespective of racial background, as "race-slumpers". He wrote that in the past, "the backward branches of the tree of mankind" had been lopped off as "the American Indians, the Black Australians, the Mauris and the negroes had been driven by bloodshed from their lands", unaware of "the biological rationality of that destiny". He advocated what he saw as a more enlightened solution: by birth control, by sterilization, and by "life in adapted reserves and asylums", where the "races which have served their turn [should] be brought to euthanasia." He considered blacks to be naturally inferior, on account of their supposedly "small skull capacity". In 1937, he praised the Third Reich for their eugenic laws and for "being the first to adopt sterilization together with a policy of racial improvement". In 1938, after newspapers had reported on the segregation of Jews into ghettos and concentration camps, he commented that the rise of Germany "should be welcomed by the religious man as reassuring evidence that in spite of modern wealth and ease, we shall not be allowed ... to adopt foolish social practices in fatal detachment from the stream of evolution". In late 1937, Cattell moved to the US on the invitation of the psychologist Edward Thorndike of Columbia University, also involved in eugenics. He spent the rest of his life there as a research psychologist, devoting himself after retirement to devising and publicising a refined version of his ideology from the 1930s that he called beyondism. In 1935, Otto Klineberg wrote two books, Negro Intelligence and Selective Migration and Race Differences, dismissing claims that African Americans in the northern states were more intelligent than those in the south. He argued that there was no scientific proof of racial differences in intelligence and that this should not therefore be used as a justification for policies in education or employment. The hereditarian view began to change in the 1920s in reaction to excessive eugenicist claims regarding abilities and moral character, and also due to the development of convincing environmental arguments. In the 1940s many psychologists, particularly social psychologists, began to argue that environmental and cultural factors, as well as discrimination and prejudice, provided a more probable explanation of disparities in intelligence. According to Franz Samelson, this change in attitude had become widespread by then, with very few studies in race differences in intelligence, a change brought out by an increase in the number of psychologists not from a "lily-white ... Anglo-Saxon" background but from Jewish backgrounds. Other factors that influenced American psychologists were the economic changes brought about by the depression and the reluctance of psychologists to risk being associated with the Nazi claims of a master race. The 1950 race statement of UNESCO, prepared in consultation with scientists including Klineberg, created a further taboo against conducting scientific research on issues related to race. Adolf Hitler banned IQ testing for being "Jewish" as did Joseph Stalin for being "bourgeois".
1960–1980
In 1965 William Shockley, Nobel laureate in physics and professor at Stanford University, made a public statement at the Nobel conference on "Genetics and the Future of Man" about the problems of "genetic deterioration" in humans caused by "evolution in reverse". He claimed social support systems designed to help the disadvantaged had a regressive effect. Shockley subsequently claimed the most competent American population group were the descendants of original European settlers, because of the extreme selective pressures imposed by the harsh conditions of early colonialism. Speaking of the "genetic enslavement" of African Americans, owing to an abnormally high birth rate, Shockley discouraged improved education as a remedy, suggesting instead sterilization and birth control. In the following ten years he continued to argue in favor of this position, claiming it was not based on prejudice but "on sound statistics". Shockley's outspoken public statements and lobbying brought him into contact with those running the Pioneer Fund who subsequently, through the intermediary Carleton Putnam, provided financial support for his extensive lobbying activities in this area, reported widely in the press. With the psychologist and segregationist R. Travis Osborne as adviser, he formed the Foundation for Research and Education on Eugenics and Dysgenics (FREED). Although its stated purpose was "solely for scientific and educational purposes related to human population and quality problems", FREED mostly acted as a lobbying agency for spreading Shockley's ideas on eugenics.
The Pioneer Fund had been set up by Wickliffe Draper in 1937 with one of its two charitable purposes being to provide aid for "study and research into the problems of heredity and eugenics in the human race" and "into the problems of race betterment with special reference to the people of the United States". From the late fifties onwards, following the 1954 Supreme Court decision on segregation in schools, it supported psychologists and other scientists in favour of segregation. All of these ultimately held academic positions in the Southern states, notably Henry E. Garrett (head of psychology at Columbia University until 1955), Wesley Critz George, Frank C.J. McGurk, R. Travis Osborne and Audrey Shuey, who in 1958 wrote The Testing of Negro Intelligence, demonstrating "the presence of native differences between Negroes and whites as determined by intelligence tests". In 1959 Garrett helped to found the International Association for the Advancement of Ethnology and Eugenics, an organisation promoting segregation. In 1961 he blamed the shift away from hereditarianism, which he described as the "scientific hoax of the century", on the school of thought –the "Boas cult" – promoted by his former colleagues at Columbia, notably Franz Boas and Otto Klineberg, and more generally "Jewish organizations", most of whom "belligerently support the egalitarian dogma which they accept as having been 'scientifically' proved". He also pointed to Marxist origins in this shift, writing in a pamphlet, Desegregation: Fact and hokum, that: "It is certain that the Communists have aided in the acceptance and spread of egalitarianism although the extent and method of their help is difficult to assess. Egalitarianism is good Marxist doctrine, not likely to change with gyrations in the Kremlin line." In 1951 Garrett had even gone as far as reporting Klineberg to the FBI for advocating "many Communistic theories", including the idea that "there are no differences in the races of mankind". One of Shockley's lobbying campaigns involved the educational psychologist, Arthur Jensen, of the University of California, Berkeley (UC Berkeley). Although earlier in his career Jensen had favored environmental rather than genetic factors as the explanation of race differences in intelligence, he had changed his mind during 1966-1967 when he was at the Center for Advanced Study in the Behavioral Sciences at Stanford. Here Jensen met Shockley and through him received support for his research from the Pioneer Fund. Although Shockley and Jensen's names were later to become linked in the media, Jensen does not mention Shockley as an important influence on his thought in his subsequent writings; rather he describes as decisive his work with Hans Eysenck. He also mentions his interest in the behaviorist theories of Clark L. Hull which he says he abandoned largely because he found them to be incompatible with experimental findings during his years at Berkeley.
In a 1968 article published in Disadvantaged Child, Jensen questioned the effectiveness of child development and antipoverty programs, writing: "As a social policy, avoidance of the issue could be harmful to everyone in the long run, especially to future generations of Negroes, who could suffer the most from well-meaning but misguided and ineffective attempts to improve their lot." In 1969 Jensen wrote a long article in the Harvard Educational Review, "How Much Can We Boost IQ and Scholastic Achievement?" In his article, 123 pages long, Jensen insisted on the accuracy and lack of bias in intelligence tests, stating that the absolute quantity g that they measured, the general intelligence factor, first introduced by the English psychologist Charles Spearman in 1904, "stood like a Rock of Gibraltar in psychometrics". He stressed the importance of biological considerations in intelligence, commenting that "the belief in the almost infinite plasticity of intellect, the ostrich-like denial of biological factors in individual differences, and the slighting of the role of genetics in the study of intelligence can only hinder investigation and understanding of the conditions, processes, and limits through which the social environment influences human behavior." He argued at length that, contrary to environmentalist orthodoxy, intelligence was partly dependent on the same genetic factors that influence other physical attributes. More controversially, he briefly speculated that the difference in performance at school between blacks and whites might have a partly genetic explanation, commenting that there were "various lines of evidence, no one of which is definitive alone, but which, viewed all together, make it a not unreasonable hypothesis that genetic factors are strongly implicated in the average Negro-white intelligence difference. The preponderance of the evidence is, in my opinion, less consistent with a strictly environmental hypothesis than with a genetic hypothesis, which, of course, does not exclude the influence of environment or its interaction with genetic factors." He advocated the allocation of educational resources according to merit and insisted on the close correlation between intelligence and occupational status, arguing that "in a society that values and rewards individual talent and merit, genetic factors inevitably take on considerable importance." Concerned that the average IQ in the US was inadequate to answer the increasing needs of an industrialised society, he predicted that people with lower IQs would become unemployable while at the same time there would be an insufficient number with higher IQs to fill professional posts. He felt that eugenic reform would prevent this more effectively than compensatory education, surmising that "the technique for raising intelligence per se in the sense of g, probably lie more in the province of biological science than in psychology or education". He pointed out that intelligence and family size were inversely correlated, particularly amongst the black population, so that the current trend in average national intelligence was dysgenic rather than eugenic. As he wrote, "Is there a danger that current welfare policies, unaided by eugenic foresight, could lead to the genetic enslavement of a substantial segment of our population? The fuller consequences of our failure seriously to study these questions may well be judged by future generations as our society's greatest injustice to Negro Americans." He concluded by emphasizing the importance of child-centered education. Although a tradition had developed for the exclusive use of cognitive learning in schools, Jensen argued that it was not suited to "these children's genetic and cultural heritage": although capable of associative learning and memorization ("Level I" ability), they had difficulties with abstract conceptual reasoning ("Level II" ability). He felt that in these circumstances the success of education depended on exploiting "the actual potential learning that is latent in these children's patterns of abilities". He suggested that, in order to ensure equality of opportunity, "schools and society must provide a range and diversity of educational methods, programs and goals, and of occupational opportunities, just as wide as the range of human abilities." Later, writing about how the article came into being, Jensen said that the editors of the Review had specifically asked him to include his view on the heritability of race differences, which he had not previously published. He also maintains that only five percent of the article touched on the topic of race difference in IQ. Cronbach (1975) also gave a detailed account of how the student editors of Harvard Educational Review commissioned and negotiated the content of Jensen's article. Many academics have given commentaries on what they considered to be the main points of Jensen's article and the subsequent books in the early 1970s that expanded on its content. According to Jencks & Phillips (1998), in his article Jensen had argued "that educational programs for disadvantaged children initiated as the War on Poverty had failed, and the black-white race gap probably had a substantial genetic component." They summarised Jensen's argument as follows:
"Most of the variation in black-white scores is genetic" "No one has advanced a plausible environmental explanation for the black-white gap" "Therefore it is more reasonable to assume that part of the black-white gap is genetic in origin" According to Loehlin, Lindzey & Spuhler (1975), Jensen's article defended 3 claims:
IQ tests provide accurate measurements of a real human ability that is relevant in many aspects of life. Intelligence, as measured by IQ tests, is highly (about 80%) heritable and parents with low IQs are much more likely to have children with low IQs Educational programs have been unable to significantly change the intelligence of individuals or groups. According to Webster (1997), the article claimed "a correlation between intelligence, measured by IQ tests, and racial genes". He wrote that Jensen, based on empirical evidence, had concluded that "black intelligence was congenitally inferior to that of whites"; that "this partly explains unequal educational achievements"; and that, "because a certain level of underachievement was due to the inferior genetic attributes of blacks, compensatory and enrichment programs are bound to be ineffective in closing the racial gap in educational achievements." Several commentators mention Jensen's recommendations for schooling: according to Barry Nurcombe,
Jensen's own research suggests that IQ tests amalgamate two forms of thinking which are hierarchically related but which become differentially distributed in the population according to SES: level 1 and level 2, associative learning and abstract thinking (g), respectively. Blacks do as well as whites on tests of associative learning, but they fall behind on abstract thinking. The educational system should attend to this discrepancy and derive a more pluralistic approach. The current system puts minority groups at a marked disadvantage, since it overemphasizes g-type thinking. Jensen had already suggested in the article that initiatives like the Head Start Program were ineffective, writing in the opening sentence, "Compensatory education has been tried and it apparently has failed." Other experts in psychometrics, such as Flynn (1980) and Mackintosh (1998), have given accounts of Jensen's theory of Level I and Level II abilities, which originated in this and earlier articles. As the historian of psychology William H. Tucker commented, Jensen's question is leading: "Is there a danger that current welfare policies, unaided by eugenic foresight, could lead to the genetic enslavement of a substantial segment of our population? The fuller consequences of our failure seriously to study these questions may well be judged by future generations as our society's greatest injustice to Negro Americans". Tucker noted that it repeats Shockley's phrase "genetic enslavement", which proved later to be one of the most inflammatory statements in the article. Shockley conducted a widespread publicity campaign for Jensen's article, supported by the Pioneer Fund. Jensen's views became widely known in many spheres. As a result, there was renewed academic interest in the hereditarian viewpoint and in intelligence tests. Jensen's original article was widely circulated and often cited; the material was taught in university courses over a range of academic disciplines. In response to his critics, Jensen wrote a series of books on all aspects of psychometrics. There was also a widespread positive response from the popular press — with The New York Times Magazine dubbing the topic "Jensenism" — and amongst politicians and policy makers. In 1971 Richard Herrnstein wrote a long article on intelligence tests in The Atlantic for a general readership. Undecided on the issues of race and intelligence, he discussed instead score differences between social classes. Like Jensen he took a firmly hereditarian point of view. He also commented that the policy of equal opportunity would result in making social classes more rigid, separated by biological differences, resulting in a downward trend in average intelligence that would conflict with the growing needs of a technological society. Jensen and Herrnstein's articles were widely discussed. Hans Eysenck defended the hereditarian point of view and the use of intelligence tests in "Race, Intelligence and Education" (1971), a pamphlet presenting Jensenism to a popular audience, and "The Inequality of Man" (1973). He was severely critical of anti-hereditarians whose policies he blamed for many of the problems in society. In the first book he wrote that, "All the evidence to date suggests the strong and indeed overwhelming importance of genetic factors in producing the great variety of intellectual differences which [are] observed between certain racial groups", adding in the second, that "for anyone wishing to perpetuate class or caste differences, genetics is the real foe". "Race, Intelligence and Education" was immediately criticized in strong terms by IQ researcher Sandra Scarr as an "uncritical popularization of Jensen's ideas without the nuances and qualifiers that make much of Jensen's writing credible or at least responsible." Later scholars have identified errors and suspected data manipulation in Eysenck's work. An inquiry on behalf of King's College London found 26 of his papers to be "incompatible with modern clinical science". Rod Buchanan, a biographer of Eysenck, has argued that 87 publications by Eysenck should be retracted. Student groups and faculty at Berkeley and Harvard protested Jensen and Herrnstein with charges of racism. Two weeks after the appearance of Jensen's article, Students for a Democratic Society staged protests against Arthur Jensen on the campus of the University of California, Berkeley, chanting "Fight racism. Fire Jensen!" Jensen himself states that he even lost his employment at Berkeley because of the controversy. Similar campaigns were waged in London against Eysenck and in Boston against sociobiologist Edward Wilson. The attacks on Wilson were orchestrated by the Sociobiology Study Group, part of the left wing organization Science for the People, formed of 35 scientists and students, including the Harvard biologists Stephen J. Gould and Richard Lewontin, who both became prominent critics of hereditarian research in race and intelligence. In 1972 50 academics, including the psychologists Jensen, Eysenck, and Herrnstein as well as five Nobel laureates, signed a statement entitled "Resolution on Scientific Freedom Regarding Human Behavior and Heredity", criticizing the climate of "suppression, punishment and defamation of scientists who emphasized the role of heredity in human behavior". In October 1973 a half-page advertisement entitled "Resolution Against Racism" appeared in The New York Times. With over 1000 academic signatories, including Lewontin, it condemned "racist research", denouncing in particular Jensen, Shockley and Herrnstein. This was accompanied by commentaries, criticisms and denouncements from the academic community. Two issues of the Harvard Educational Review were devoted to critiques of Jensen's work by psychologists, biologists and educationalists. As documented by Wooldridge (1995), the main commentaries involved: population genetics (Richard Lewontin, Luigi Cavalli-Sforza, Walter Bodmer); the heritability of intelligence (Christopher Jencks, Mary Jo Bane, Leon Kamin, David Layzer); the possible inaccuracy of IQ tests as measures of intelligence (summarised in Jensen 1980, pp. 20–21); and sociological assumptions about the relationship between intelligence and income (Jencks and Bane). More specifically, the Harvard biologist Richard Lewontin commented on Jensen's use of population genetics, writing that, "The fundamental error of Jensen's argument is to confuse heritability of character within a population with heritability between two populations." Jensen denied making such a claim, saying that his argument was that high within-group heritability increased the probability of non-zero between-group heritability. The political scientists Christopher Jencks and Mary Jo Bane, also from Harvard, recalculated the heritability of intelligence as 45% instead of Jensen's estimate of 80%; and they calculated that only about 12% of variation in income was due to IQ, so that in their view the connections between IQ and occupation were less clear than Jensen had suggested. Ideological differences also emerged in the controversy. The circle of scientists around Lewontin and Gould rejected the research of Jensen and Herrnstein as "bad science". While not objecting to research into intelligence per se, they felt that this research was politically motivated and objected to the reification of intelligence: the treatment of the numerical quantity g as a physical attribute like skin color that could be meaningfully averaged over a population group. They claimed that this was contrary to the scientific method, which required explanations at a molecular level, rather than the analysis of a statistical artifact in terms of undiscovered processes in biology or genetics. In response to this criticism, Jensen later wrote: "... what Gould has mistaken for 'reification' is neither more nor less than the common practice in every science of hypothesizing explanatory models to account for the observed relationships within a given domain. Well known examples include the heliocentric theory of planetary motion, the Bohr atom, the electromagnetic field, the kinetic theory of gases, gravitation, quarks, Mendelian genes, mass, velocity, etc. None of these constructs exists as a palpable entity occupying physical space." He asked why psychology should be denied "the common right of every science to the use of hypothetical constructs or any theoretical speculation concerning causal explanations of its observable phenomena".
The academic debate also became entangled with the so-called "Burt Affair", because Jensen's article had partially relied on the 1966 twin studies of the British educational psychologist Sir Cyril Burt: shortly after Burt's death in 1971, there were allegations, prompted by research of Leon Kamin, that Burt had fabricated parts of his data, charges which have never been fully resolved. Franz Samelson documents how Jensen's views on Burt's work varied over the years: Jensen was Burt's main defender in the US during the 1970s. In 1983, following the publication in 1978 of Leslie Hearnshaw's official biography of Burt, Jensen changed his mind, "fully accept[ing] as valid ... Hearnshaw's biography" and stating that "of course [Burt] will never be exonerated for his empirical deceptions". However, in 1992, he wrote that "the essence of the Burt affair ... [was] a cabal of motivated opponents, avidly aided by the mass media, to bash [Burt's] reputation completely", a view repeated in an invited address on Burt before the American Psychological Association, when he called into question Hearnshaw's scholarship.
Similar charges of a politically motivated campaign to stifle scientific research on racial differences, later dubbed "Neo-Lysenkoism", were frequently repeated by Jensen and his supporters. Jensen (1972) bemoaned the fact that "a block has been raised because of the obvious implications for the understanding of racial differences in ability and achievement. Serious considerations of whether genetic as well as environmental factors are involved has been taboo in academic circles", adding that: "In the bizarre racist theories of the Nazis and the disastrous Lysenkoism of the Soviet Union under Stalin, we have seen clear examples of what happens when science is corrupted by subservience to political dogma." After the appearance of his 1969 article, Jensen was later more explicit about raci