The history of the race and intelligence controversy concerns the historical development of a debate, concerning 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 average scores of different population groups, but there has been no agreement about whether this is mainly due to environmental and cultural factors, or mainly due to some genetic factor, or even if the dichotomy between environmental and genetic factors is the most effectual approach to the debate.
In the late 19th and early 20th century, group differences in intelligence were assumed to be due to race; apart from intelligence tests, research relied on measurements such as brain size or reaction times. By the mid-1930s 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 had 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. One contemporary response was a report from the American Psychological Association that found no conclusive explanation for the observed differences between average IQ scores of racial groups.
History
Early history
Lithograph of a North American skull from Samuel Morton's Crania Americana, 1839. Morton believed that intelligence was correlated with brain size and varied between racial groups
Francis Galton, the English eugenicist who wrote extensively on the relation between intelligence and social class
In the 18th century, European philosophers and scientists such as Voltaire, David Hume, Immanuel Kant, and Carl Linnaeus, proposed the existence of different mental abilities among the races.
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 these differences explained the different intelligences, was
much advocated and studied.
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 argued that intelligence was normally distributed
in all racial and ethnic groups, and that the means of the distributions
varied between the groups. In Galton's estimation ancient Attic Greeks
had been the people with the highest average intelligence, followed by
contemporary Englishmen, with black Africans at a lower level, and
Australian Aborigines lower still. He did not specifically study Jews, but remarked that "they appear to be rich in families of high intellectual breeds".
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 demonstrating increased reaction
times among White Americans when compared with those of Native Americans
and African Americans, with Native Americans having the shortest
reaction time. He hypothesized that the long 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 science was used to bolster beliefs in the superiority of a particular race.
In 1912 the Columbia psychology graduate Frank Bruner reviewed
the scientific literature on auditory perception in black and white
subjects in
Psychological Bulletin,
characterizing, "the mental qualities of the Negro 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."
Alfred Binet (1857-1911), inventor of the first intelligence test
Lewis Terman, psychologist and developer of the Stanford-Binet intelligence test
The psychologist Henry H. Goddard had suggested with Terman that "feeble-mindedness" was hereditary
In 1916 George O. Ferguson conducted research in his Columbia Ph.D. thesis on "The psychology of the Negro", finding them poor in abstract thought, but good in physical responses, recommending how this should be reflected in education. In the same year Lewis Terman, in the manual accompanying the Stanford-Binet Intelligence Test, referred to the higher frequency of "morons"
among non-white American racial groups stating that further research
into race difference on intelligence should be conducted and that the
"enormously significant racial differences in general intelligence"
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
USA, however, independently and prior to the IQ tests, there had been
political pressure for such eugenic
policies, to be enforced by sterilization; in due course IQ tests were
later used as justification for sterilizing the mentally retarded.
It was also argued that the IQ tests should be used to control
immigration to the USA. Already in 1917 Goddard reported on the low IQ
scores of new arrivals at Ellis Island;
and Yerkes argued from his army test scores that there were
consistently lower IQ levels among those from Eastern and Southern
Europe, which could lead to a decline in the national intelligence. In
1923, in his book A study of American intelligence, Carl Brigham
wrote that on the basis of the 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 scholar's 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."
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 factors that accounted for differences.
Nevertheless, he conceded 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 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 rationalized 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 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."
Franz Boas, regarded as the father of anthropology in the US, had a lasting influence on the work of Otto Klineberg and his generation
He considered blacks to be naturally inferior, on account of "their 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 from 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
William
Shockley, the Nobel laureate in physics, suggested that the decline in
the average IQ in the US could be solved by eugenics
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.
Wickliffe Draper, founder of the Pioneer Fund
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
onward, following the 1954 Supreme Court decision
on segregation in schools, it supported psychologists and other
scientists in favor 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 equalitarian 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 equalitarianism although the extent and method of their help
is difficult to assess. Equalitarianism 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.
Arthur Jensen,
professor of educational psychology at UC Berkeley who wrote the 1969
article on intelligence that became one of the most controversial
articles in the history of psychology
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?"
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In
October 1967 Arthur Jensen gave an invited address with the same title
as his article at the annual meeting of the California Advisory Council
of Educational Research in San Diego
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 USA was
inadequate to answer the increasing needs of an industrialized 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 summarized 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
comments, Jensen's leading question,"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," repeating Shockley's phrase "genetic
enslavement", proved later to be one of the most inflammatory statements
in the article.
Raymond Cattell, one of Jensen's main supporters who referred to his opponents as "ignoracists"
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.
Hans Eysenck, professor of psychology at the Institute of Psychiatry and Jensen's mentor
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."
Although the main intention of the hereditarians had been to
challenge the anti-hereditarian establishment, they were unprepared for
the level of reaction and censure in the scientific world. Militant student groups
at Berkeley and Harvard conducted campaigns of harassment on Jensen and
Herrnstein with charges of racism, despite Herrnstein's refusal to
endorse Jensen's views on race and intelligence.
Two weeks after the appearance of Jensen's article, the Berkeley chapter
of the student organization 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 Edward Wilson, the founding father of sociobiology, the discipline that explains human behavior through genetics. 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 a high level of 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
determined 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, some of them
self-admittedly motivated by a Marxist ideology, 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 colour 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?"
Cyril Burt, the English educationalist whose disputed twin studies had been used as data by Jensen in some of his early articles and books
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 USA 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.
Trofim Lysenko who, as director of Soviet research in biology under Joseph Stalin, blocked research into genetics for ideological reasons
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 racial differences in intelligence, stating in 1973 "that
something between one-half and three-fourths of the average IQ
differences between American Negroes and whites is attributable to
genetic factors." He even speculated that the underlying mechanism was a
"biochemical connection between skin pigmentation and intelligence"
linked to their joint development in the ectoderm
of the embryo. Although Jensen avoided any personal involvement with
segregationists in the US, he did not distance himself from the
approaches of journals of the far right in Europe, many of whom viewed
his research as justifying their political ends. In an interview with Nation Europa,
he said that some human races differed from one another even more than
some animal species, claiming that a measurement of "genetic distance"
between blacks and whites showed that they had diverged over 46,000
years ago. He also granted interviews to Alain de Benoist's French journal Nouvelle École and Jürgen Rieger's German journal Neue Anthropologie
of which he later became a regular contributor and editor, apparently
unaware of its political orientation owing to his poor knowledge of
German.
The debate was further exacerbated by issues of racial bias that
had already intensified through the 1960s because of civil rights
concerns and changes in the social climate. In 1968 the Association of Black Psychologists
(ABP) had demanded a moratorium on IQ tests for children from minority
groups.
After a committee set up by the American Psychological Association drew
up guidelines for assessing minority groups, failing to confirm the
claims of racial bias, Jackson (1975) wrote the following as part of a response on behalf of the ABP:
Psychological testing historically has been a quasi-scientific tool in the perpetuation of racism on all levels of scientific objectivity, it [testing] has provided a cesspool of intrinsically and inferentially fallacious data which inflates the egos of whites by demeaning Black people and threatens to potentiate Black genocide.
Other professional academic bodies reacted to the dispute differently. The Society for the Psychological Study of Social Issues, a division of the American Psychological Society,
issued a public statement in 1969 criticizing Jensen's research,
declaring that, "To construct questions about complex behavior in terms
of heredity versus environment is to oversimplify the essence and nature of human development and behavior." The American Anthropological Association
convened a panel discussion in 1969 at its annual general meeting,
shortly after the appearance of Jensen's paper, where several
participants labelled his research as "racist".
Subsequently, the association issued an official clarification, stating
that, "The shabby misuse of IQ testing in the support of past American
racist policies has created understandable anxiety over current research
on the inheritance of human intelligence. But the resulting personal
attacks on a few scientists with unpopular views has had a chilling
effect on the entire field of behavioral genetics and clouds public
discussion of its implications." In 1975 the Genetics Society of America
made a similarly cautious statement: "The application of the techniques
of quantitative genetics to the analysis of human behavior is fraught
with human complications and potential biases, but well-designed
research on the genetic and environmental components of human
psychological traits may yield valid and socially useful results and
should not be discouraged."
1980–2000
Jim Flynn, the New Zealand political scientist who has studied changes in IQ scores
In the 1980s, the political scientist Jim Flynn
compared the results of groups who took both older and newer versions
of specific IQ tests. His research led him to the discovery of what is
now called the Flynn effect:
a substantial increase in average IQ scores over the years across all
groups tested. His discovery was confirmed later by many other studies.
While trying to understand these remarkable test score increases, Flynn
had postulated in 1987 that "IQ tests do not measure intelligence but rather a correlate with a weak causal link to intelligence".
By 2009, however, Flynn felt that the IQ test score changes are real.
He suggests that our fast-changing world has faced successive
generations with new cognitive challenges that have considerably
stimulated intellectual ability. "Our brains as presently constructed
probably have much excess capacity ready to be used if needed. That was
certainly the case in 1900."
Flynn notes that "Our ancestors in 1900 were not mentally retarded.
Their intelligence was anchored in everyday reality. We differ from them
in that we can use abstractions and logic and the hypothetical to
attack the formal problems that arise when science liberates thought
from concrete situations. Since 1950, we have become more ingenious in
going beyond previously learned rules to solve problems on the spot."
Richard Lynn, the English psychologist who has written extensively on global group differences in intelligence
From the 1980s onwards, the Pioneer Fund continued to fund
hereditarian research on race and intelligence, in particular the two
English-born psychologists Richard Lynn of the University of Ulster and J. Philippe Rushton of the University of Western Ontario,
its president since 2002. Rushton returned to the cranial measurements
of the 19th century, using brain size as an extra factor determining
intelligence; in collaboration with Jensen, he most recently developed
updated arguments for the genetic explanation of race differences in
intelligence.
Lynn, longtime editor of and contributor to Mankind Quarterly
and a prolific writer of books, has concentrated his research in race
and intelligence on gathering and tabulating data about race differences
in intelligence across the world. He has also made suggestions about
its political implications, including the revival of older theories of
eugenics, which he describes as "the truth that dares not speak its
name".
Snyderman & Rothman (1987)
announced the results of a survey conducted in 1984 on a sample of over
a thousand psychologists, sociologists and educationalists in a
multiple choice questionnaire, and expanded in 1988 into the book The IQ Controversy, the Media, and Public Policy.
The book claimed to document a liberal bias in the media coverage of
scientific findings regarding IQ. The survey included the question,
"Which of the following best characterizes your opinion of the
heritability of black-white differences in IQ?" 661 researchers returned
the questionnaire, and of these, 14% declined to answer the question,
24% voted that there was insufficient evidence to give an answer, 1%
voted that the gap was purely "due entirely to genetic variation", 15%
voted that it "due entirely due to environmental variation" and 45%
voted that it was a "product of genetic and environmental variation".
Jencks & Phillips (1998)
have pointed out that those who replied "both" did not have the
opportunity to specify whether genetics played a large role. There has
been no agreement amongst psychometricians on the significance of this particular answer. Scientists supporting the hereditarian point of view have seen it as a vindication of their position.
In 1989 J. Philippe Rushton was placed under police investigation by the Attorney General of Ontario, after complaints that he had promoted racism in one of his publications on race differences. In the same year, Linda Gottfredson of the University of Delaware
had an extended battle with her university over the legitimacy of
grants from the Pioneer Fund, eventually settled in her favor.
Both later responded with an updated version of Henry E.
Garrett's "equalitarian dogma", labeling the claim that all races were
equal in cognitive ability as an "egalitarian fiction" and a "scientific
hoax". Gottfredson (1994)
spoke of a "great fraud", a "collective falsehood" and a "scientific
lie", citing the findings of Snyderman and Rothman as justification. Rushton (1996)
wrote that there was a "taboo on race" in scientific research that had
"no parallel... not the Inquisition, not Stalin, not Hitler." In his 1998 book "The g Factor: The Science of Mental Ability", Jensen reiterated his earlier claims of Neo-Lysenkoism,
writing that "The concept of human races [as] a fiction" has various
"different sources, none of them scientific," one of them being
"Neo-Marxist philosophy," which "excludes consideration of genetic or
biological factors ... from any part in explaining behavioral
differences amongst humans." In the same year the evolutionary psychologist Kevin B. MacDonald
went much further, reviving Garrett's claim of the "Boas cult" as a
Jewish conspiracy, after which "research on racial differences ceased,
and the profession completely excluded eugenicists like Madison Grant and Charles Davenport."
In 1994 the debate on race and intelligence was reignited by the publication of the book
The Bell Curve: Intelligence and Class Structure in American Life by Richard Herrnstein and Charles Murray. The book was received positively by the media, with prominent coverage in Newsweek, Time, the New York Times and the Wall Street Journal.
Although only two chapters of the book were devoted to race differences
in intelligence, treated from the same hereditarian standpoint as
Jensen's 1969 paper, it nevertheless caused a similar furore in the
academic community to Jensen's article. Many critics, including Stephen
J. Gould and Leon Kamin, asserted that the book contained unwarranted
simplifications and flaws in its analysis; in particular there were
criticisms of its reliance on Lynn's estimates of average IQ scores in South Africa,
where data had been used selectively, and on Rushton's work on brain
size and intelligence, which was controversial and disputed. These
criticisms were subsequently presented in books, most notably The Bell Curve Debate (1995), Inequality by Design: Cracking the Bell Curve Myth (1996) and an expanded edition of Gould's The Mismeasure of Man (1996).
In 1994 a group of 52 scientists, including Rushton, Lynn, Jensen and Eysenck, were cosignatories of an op-ed article in the Wall Street Journal written by Linda Gottfredson entitled "Mainstream Science on Intelligence". The article, supporting the conclusions of The Bell Curve, was later republished in an expanded version in the journal Intelligence. The editorial included the statements:
Genetics plays a bigger role than environment in creating IQ differences among individuals ... The bell curve for whites is centered roughly around IQ 100; the bell curve for American blacks roughly around 85 ... black 17-year olds perform, on the average, more like white 13-year olds in reading, math and science, with Hispanics in between.
Another early criticism was that Herrnstein and Murray did not submit their work to academic peer review before publication. There were also three books written from the hereditarian point of view: Why race matters: race differences and what they mean (1997) by Michael Levin; The g Factor: The Science of Mental Ability (1998) by Jensen; and Intelligence; a new look by Hans Eysenck. Various other books of collected contributions appeared at the same time, including The black-white test gap (1998) edited by Christopher Jencks and Meredith Phillips, Intelligence, heredity and environment (1997) edited by Robert Sternberg and Elena Grigorenko. A section in IQ and human intelligence (1998) by Nicholas Mackintosh discussed ethnic groups and Race and intelligence: separating science from myth (2002) edited by Jefferson Fish presented further commentary on The Bell Curve by anthropologists, psychologists, sociologists, historians, biologists and statisticians.
In 1999 the same journal Intelligence reprinted as an invited editorial a long article by the attorney Harry F. Weyher Jr.
defending the integrity of the Pioneer Fund, of which he was then
president and of which several editors, including Gottfredson, Jensen,
Lynn and Rushton, were grantees. In 1994 the Pioneer-financed journal Mankind Quarterly, of which Roger Pearson was the manager and pseudonymous contributor, had been described by Charles Lane in a review of The Bell Curve in the New York Review of Books
as "a notorious journal of 'racial history' founded, and funded, by men
who believe in the genetic superiority of the white race"; he had
called the fund and its journal "scientific racism's keepers of the
flame." Gottfredson had previously defended the fund in 1989-1990,
asserting that Mankind Quarterly was a "multicultural journal" dedicated
to "diversity ... as an object of dispassionate study" and that Pearson
did not approve of membership of the American Nazi Party. Pearson (1991) had himself defended the fund in his book Race, Intelligence and Bias in Academe.
In response to the debate on The Bell Curve, the American Psychological Association set up a ten-person taskforce, chaired by Ulrich Neisser, to report on the book and its findings. In its report, "Intelligence: Knowns and Unknowns", published in February 1996, the committee made the following comments on race differences in intelligence:
African American IQ scores have long averaged about 15 points below those of Whites, with correspondingly lower scores on academic achievement tests. In recent years the achievement-test gap has narrowed appreciably. It is possible that the IQ-score differential is narrowing as well, but this has not been clearly established. The cause of that differential is not known; it is apparently not due to any simple form of bias in the content or administration of the tests themselves. The Flynn effect shows that environmental factors can produce differences of at least this magnitude, but that effect is mysterious in its own right. Several culturally-based explanations of the Black/White IQ differential have been proposed; some are plausible, but so far none has been conclusively supported. There is even less empirical support for a genetic interpretation. In short, no adequate explanation of the differential between the IQ means of Blacks and Whites is presently available.
Jensen commented:
As I read the APA statement, [...] I didn't feel it was contradicting my position, but rather merely sidestepping it. It seems more evasive of my position than contradictory. The committee did acknowledge the factual status of what I have termed the Spearman Effect, the reality of g, the inadequacy of test bias and socioeconomic status as causal explanations, and many other conclusions that don't differ at all from my own position. [...] Considering that the report was commissioned by the APA, I was surprised it went as far as it did. Viewed in that light, I am not especially displeased by it.
Rushton found himself at the centre of another controversy in 1999
when unsolicited copies of a special abridged version of his 1995 book Race, Evolution and Behavior,
aimed at a general readership, were mass mailed to psychologists,
sociologists and anthropologists in North American universities. As a
result, Transaction Publishers
withdrew from publishing the pamphlet, financed by the Pioneer Fund,
and issued an apology in the January 2000 edition of the journal Society.
In the pamphlet Rushton recounted how black Africans had been seen by
outside observers through the centuries as naked, insanitary,
impoverished and unintelligent. In modern times he remarked that their
average IQ of 70 "is the lowest ever recorded", due to smaller average
brain size. He explained these differences in terms of evolutionary
history: those that had migrated to colder climates in the north to
evolve into whites and Asians had adapted genetically to have more
self-control, lower levels of sex hormones, greater intelligence, more
complex social structures, and more stable families. He concluded that
whites and Asians are more disposed to "invest time and energy in their
children rather than the pursuit of sexual thrills. They are 'dads'
rather than 'cads.'" J. Philippe Rushton did not distance himself from
groups on the far right in the US. He was a regular contributor to the
newsletters of American Renaissance and spoke at many of their biennial conferences, in 2006 sharing the platform with Nick Griffin, leader of the British National Party.
2000–present
In 2002, Richard Lynn and Tatu Vanhanen, published IQ and the Wealth of Nations.
Vanhanen claimed "Whereas the average IQ of Finns is 97, in Africa it
is between 60 and 70. Differences in intelligence are the most
significant factor in explaining poverty." A complaint by Finland's
"Ombudsman for Minorities", Mikko Puumalainen, resulted in Vanhanen
being considered to be investigated for incitement of "racial hatred" by
the Finnish National Bureau of Investigations. In 2004, the police stated they found no reason to suspect he incited racial hatred and decided not to launch an investigation.
Several negative reviews of the book have been published in the
scholarly literature. Susan Barnett and Wendy Williams wrote that "we
see an edifice built on layer upon layer of arbitrary assumptions and
selective data manipulation.
The data on which the entire book is based are of questionable validity
and are used in ways that cannot be justified." They also wrote that
cross country comparisons are "virtually meaningless."
Richardson (2004) argued, citing the Flynn effect
as the best evidence, that Lynn has the causal connection backwards and
suggested that "the average IQ of a population is simply an index of
the size of its middle class, both of which are results of industrial
development". The review concludes that "This is not so much science,
then, as a social crusade."
A review by Michael Palairet criticized the book's methodology,
particularly the imprecise estimates of GDP and the fact that IQ data
were only available for 81 of the 185 countries studied. However, the
review concluded that the book was "a powerful challenge to economic
historians and development economists who prefer not to use IQ as an
analytical input", but that it's likely those scholars will deliberately
ignore this work instead of improving it.
In a meta-analysis of studies of IQ estimates in Sub-Saharan Africa, Wicherts, Dolan & van der Maas (2009,
p. 10) concluded that Lynn and Vanhanen had relied on unsystematic
methodology by failing to publish their criteria for including or
excluding studies. They found that Lynn and Vanhanen's exclusion of
studies had depressed their IQ estimate for sub-Saharan Africa, and that
including studies excluded in IQ and Global Inequality
resulted in average IQ of 82 for sub-Saharan Africa, lower than the
average in Western countries, but higher than Lynn and Vanhanen's
estimate of 67. Wicherts at al. conclude that this difference is likely
due to sub-Saharan Africa having limited access to modern advances in
education, nutrition and health care. A 2010 systematic review by the same research team, along with Jerry S. Carlson,
found that compared to American norms, the average IQ of sub-Saharan
Africans was about 80. The same review concluded that the Flynn effect
had not yet taken hold in sub-Saharan Africa.
A 2007 meta-analysis by Rindermann found many of the same
groupings and correlations found by Lynn and Vanhanen, with the lowest
scores in sub-Saharan Africa, and a correlation of .60 between cognitive
skill and GDP per capita. Hunt (2010,
pp. 437–439) considers Rindermann's analysis to be much more reliable
than Lynn and Vanhanen's. By measuring the relationship between
educational data and social well-being over time, this study also
performed a causal analysis, finding that nations investing in education
leads to increased well-being later on. Kamin (2006) has also criticized Lynn and Vanhanen's work on the IQs of sub-Saharan Africans.
Wicherts, Borsboom & Dolan (2010) argue that studies
reporting support for evolutionary theories of intelligence based on
national IQ data suffer from multiple fatal methodological flaws. For
example, they state that such studies "...assume that the Flynn Effect
is either nonexistent or invariant with respect to different regions of
the world, that there have been no migrations and climatic changes over
the course of evolution, and that there have been no trends over the
last century in indicators of reproductive strategies (e.g., declines in
fertility and infant mortality)." They also showed that a strong degree
of confounding exists between national IQs and current national
development status.
Similarly, Pesta & Poznanski (2014) showed that the average
temperature of a given U.S. state is strongly associated with that
state's average IQ and other well-being variables, despite the fact that
evolution has not had enough time to operate on non-Native American
residents of the United States. They also noted that this association
persisted even after controlling for race, and concluded that "Evolution
is therefore not necessary for temperature and IQ/well-being to co-vary
meaningfully across geographic space."
In 2007 James D. Watson, Nobel laureate in biology, gave a controversial interview to the Sunday Times Magazine during a book tour in the United Kingdom.
Watson stated he was “inherently gloomy about the prospect of Africa”
because “all our social policies are based on the fact that their
intelligence is the same as ours – whereas all the testing says not
really.” He also wrote that “there is no firm reason to anticipate that
the intellectual capacities of peoples geographically separated in their
evolution should prove to have evolved identically. Our wanting to
reserve equal powers of reason as some universal heritage of humanity
will not be enough to make it so.” This resulted in the cancellation of a
Royal Society lecture, along with other public engagements, and his suspension from his administrative duties at Cold Spring Harbor Laboratory.
He subsequently cancelled the tour and resigned from his position at
CSHL, where he had served as either director, president or chancellor
since 1968. However, Watson was later appointed chancellor emeritus of
CSHL, and, as of 2009, he continued to advise and guide project work at
the laboratory.
In 2005 the journal Psychology, Public Policy and Law of the American Psychological Association (APA) published a review article by Rushton and Jensen, "Thirty Years of Research on Race Differences in Cognitive Ability". The article was followed by a series of responses, some in support, some critical. Richard Nisbett,
another psychologist who had also commented at the time, later included
an amplified version of his critique as part of the book Intelligence and How to Get It: Why Schools and Cultures Count (2009).
Rushton and Jensen in 2010 made a point-for-point reply to this and
again summarized the hereditarian position in "Race and IQ: A
theory-based review of the research in Richard Nisbett's Intelligence
and How to Get It".
In 2016, Rindermann, Becker & Coyle (2016) attempted to replicate the findings of Snyderman & Rothman (1987)
by surveying 71 psychology experts on the causes of international
differences in cognitive test scores. They found that the experts
surveyed ranked education as the most important factor of these
differences, with genetics in second place (accounting in average for
15% of the gap, with high variability in estimates among experts) and
health, wealth, geography, climate, and politics as the next most
important factors. About 90% of experts in the survey believed there was
a genetic component to international IQ gaps.
