<P> 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 . </P> <P> 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?" </P> <P> 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 . </P> <P> 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 ." </P>

Who said that intelligence is the ability to one surrounding