The largest difference is between blacks and Asians, or possibly if the white/Asian gap is not accepted, between blacks and whites and Asians. Lynn and Vanhanen estimate the average of IQ of blacks in sub-Saharan Africa at 70. Startlingly low many will think. I have more to say on this subject in section 26.
Estimates of black IQs elsewhere are problematic because so much of the evidence comes from the USA where there is a substantial white admixture within the black population. The consensus amongst academics is that the American black population has an average IQ of 85. Interestingly, this is similar to the average IQ found amongst the mixed race population of SA which was traditionally known as coloured. This is strong circumstantial evidence for a large genetic component to IQ.
Logic would suggest that if genetics is the prime mover in determining IQ, the part of the black American population without any white admixture would have an average IQ similar to that of the sub-Saharan black population. I have not been able to locate any study which attempts to sort the IQs of the “black” US population by racial composition, but Lynn and Vanhanen’s calculated IQs for countries outside Africa which have overwhelmingly black populations and whose blacks have little white admixture support such a view, for instance, Jamaica with an average national IQ of 72. (IQ and the Wealth of Nations p76).
The difference between whites and Asians is much less stark, if it exists at all. The majority of studies support such a difference, although a few such as that of Harold Stevenson suggest otherwise. Stephenson “administered a battery of mental tests to elementary school children in Japan, Taiwan and Minnesota…Stevenson and his colleagues carefully matched children in socioeconomic and demographic variables. No significant difference in overall IQ was found and Stevenson and his colleagues concluded ‘This study offers no support for the argument that there are differences in the general cognitive functioning of Chinese, Japanese and American children.” (The Bell Curve p274)
The authors of the Bell Curve, Murray and Herrstein reviewed the literature thoroughly and concluded: “In our judgement, the balance of the evidence supports the proposition that the overall Asian mean is higher than the white mean. If we had to put a number on it, three IQ points currently most resembles a consensus, tentative though it still is (The Bell Curve P276).
Lynn and Vahanan (pp 74-77 IQ and the Wealth of Nations) give average IQs of China 100, Japan 106, North Korea 104, South Korea 106.
However, IQs are not of a piece. For example, men and women score similarly but women have a narrower distribution than men, that is, fewer representatives at the extremes of the distribution. Similarly, there are differences in IQ configurations for blacks, whites and Asians.
Blacks score more strongly on verbal questions than the visiospatial; whites are best balanced between verbal and visiospatial, while Asians show slightly less strongly on verbal questions and significantly more strongly on the visospatial than whites, viz:
“East Asians living overseas score about the same or slightly lower than whites on verbal IQ and substantially higher on visiospatial IQ. Even in the rare studies that have found overall Japanese or Chinese IQs no higher than white IQs (e.g., the Stevenson study of Japanese, Taiwanese and Minnesotans mentioned previously) the discrepancy between verbal and visospatial IQ persists. For Japanese living in Asia, a 1987 review of the literature demonstrated without much question that the verbal-visiospatial difference persists even in examinations thoroughly adapted to the Japanese language and, indeed, in tests developed by the Japanese themselves.” (The Bell Curve p300).
That is the broad picture. It is important to realise that there are significant variations amongst the broad racial groups. In “IQ and Global Inequality” the “East Asian countries (China, Japan, South Korea, Taiwan, Hong Kong and Singapore) all have IQs in the range of 105 to 108. The 29 European countries all have IQs in the range of 92 to 102. The 19 countries of sub-Saharan Africa all have IQs in the range of 59 to 73. Much of the rest of the world has IQs in the 80-90 range.
The position of many of the world’s states is complicated by the existence of very racially mixed populations. For example, India’s calculated national IQ is 81, which is below that of US blacks. But despite such a paltry national average India manifestly has a very large component in their population of the intellectually capable, a fact attested by their growing international importance in the area of intellectual property. A low or mediocre overall national IQ does not necessarily equal no chance of social and economic advancement. What seems to be important for movement to a more sophisticated society is that there is a sufficient weight of IQ related ability rather than that all members of the society must be part of a higher IQ group (although if the number of low IQ individuals is larger than it would be in a homogeneously higher IQ population it will impose costs on a society). What that sufficient weight is problematical, but clearly there must be sufficient people throughout the IQ distribution to do the more demanding IQ tasks, whether they be jobs needing an IQ of 100 or jobs needing an IQ of 150. The necessary number of people with IQs of 140+, is probably quite small. There is almost certainly a growing need for people with IQs in the range 110-140 because of the demands made by modern technology.