ANDREW M . COLMAN ' Scientific ' Racism and the Evidence on Race and Intelligencea

In his recent book, Race, Intelligence and Education,b H. J. Eysenck has written: 'I would be prepared to assert that experts (real experts, that is) would agree with at least 90 per cent of what I am going to say-probably the true figure would be a good deal higher, but there is no point in exaggerating' (p. 15). The major thesis which his book sought to establish was 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 we observe in our culture, and much of the difference observed between certain racial groups' (p. 130). This latter assertion is demonstrably false, as will become apparent, since 'all the evidence to date' does not speak with one voice. The thesis contains two latent propositions: (a) that intellectual differences among people in our culture are overwhelmingly determined by genetic factors, and (b) that the 15-point mean I.Q. gap between black and white Americans is largely determined by genetic factors. This paper centres on the second proposition, which (as will be demonstrated) is logically and empirically independent of the first, although the vital distinction has recently been blurred by A. R. Jensen (1969)C and subsequently by Eysenck in the quotation above, and throughout his book, which draws heavily on Jensen's controversial paper. Eysenck's claims concerning the consensus of the 'experts' have been widely interpreted as implying that there is general agreement with him on the crucial second proposition concerning race and intelligence. It is normally difficult to challenge claims of this sort (Jensen has frequently made similar assertions) beyond voicing an equally unsubstantiated demur. Fortunately, however, evidence is available in this case in Pettigrew's (1964) review of the literature. Pettigrew reported that he was able to find