In The Bell Curve, Herrnstein and Murray found that the average IQ for African Americans (85) is lower than for Hispanic (89), White (103), East Asian (106), and Jewish Americans (113). In The Global Bell Curve, Lynn shows in detail that similar racial IQ/socio-economic hierarchies are indeed present within Africa, Australia, Brazil, Britain, Canada, the Caribbean, Latin America, the Netherlands, and New Zealand.
Throughout the world, Europeans and East Asians (Chinese, Japanese and Koreans) average the highest IQs and socio-economic positions. The lowest averages are found among the Aborigines in Australia and in Africans and their descendants. Intermediate positions are occupied by the Amerindians, the South Asians from the Indian sub-continent, the Maori in New Zealand, and by the mixed race peoples in South Africa, Latin America, and the Caribbean.
The same pattern is found on many other social and life history indicators, such as educational levels, earnings, health, accidents, crime, marriage, fertility, and mortality.
Lynn's new book provides fascinating historical vignettes of all the migrations and mixing of peoples. It also provides clear tables of data, which allow the reader to check the facts for themselves.
For example, in Brazil, it is the Japanese who are the highest-achieving group. They were brought in as indentured labourers to work the plantations after slavery was abolished in 1888. Yet, today, the Japanese outscore Whites on IQ tests, earn more, and are over-represented in university places. Although they are less than one percent of the total population, they comprise 17 percent of the students at the elite University of Sao Paulo.
In Caribbean countries such as Cuba, Trinidad, and Guyana, it was the Chinese and South Asians who were brought in after the end of slavery. Subsequently, they too began to do well, with the Chinese excelling and the South Asians placing intermediate to Whites and Blacks.
Twenty-two studies find Afro-Caribbeans have a median IQ of 86, which is similar to the African American mean of 85. Twelve studies find the South Asians have a median IQ of 92.
In Africa and Australia too, South Asians average intermediate to Whites and Blacks in IQ scores, educational achievement, and economic success.
At the other end of the IQ distribution, seven studies of Jews in Britain yield a median IQ of 110. In educational achievement, East Asians in Britain also outperform the indigenous Whites.
Similarly in Australia, East Asians (mostly Chinese and Vietnamese) average higher than Whites in IQ, educational achievement, and earnings. Lynn describes pockets of ethnic Chinese elsewhere in the world such as in Mexico, Argentina, and especially Hawaii, where they also do well.
These results are remarkably consistent over time, place, and situation, irrespective of the original status of the people, or the language, history, and political organization of the country concerned.
Racial stratification of what social scientists now call ”socio-economic positions” have been extensively documented by sociologists, economists and anthropologists for around half a century.
But Lynn points out that none of these have noted the associated IQ differences. The commonest explanations:
For example, political discrimination theory does not explain the high socio-economic status of Whites and East Asians throughout Latin America and the Caribbean, where they are often tiny minorities. It is also 50 years or more since the end of colonialism—the political force which was once held to be the decisive discriminating factor.
Similarly, the successes of the Chinese in Southeast Asia can only be superficially explained by their possession of Confucian values, or the successes of the Jews to the motivating effects of their minority status, or the problems of African Americans and Australian Aborigines to their being involuntary minorities.
It is particularly difficult for social scientists to explain how some peoples who have arrived in new countries as impoverished immigrants have nevertheless risen quite rapidly in the socioeconomic hierarchies and within two or three generations joined the elite. How to explain the rapid socioeconomic achievements of the Chinese, Japanese, and Koreans in the US, Canada and Latin America, in Hawaii, in Europe, and in Southeast Asia? How to explain the rapid successes of the Jews in the US, Canada, and Britain?
Furthermore, cultural values theories are often vague, impressionistic and anecdotal. And Human Capital theories fail to explain why some racial groups acquire more education than others.
Separately, in How to explain high Jewish achievement: The role of intelligence and values, an article published in Personality and Individual Differences, by Lynn and Satoshi Kanazawa (PDF), we showed that only IQ had predictive value when pitted against values theories.
Of course, if average IQ differences are the crucial determinant of racial socio-economic hierarchies, this raises the question of what causes them.
In principle, they could be wholly environmentally determined. However, Lynn argues that their consistency across time and circumstance points to genetic factors. And he reviews other data in support including hybridization studies and finds that “mixed-race” populations fall between parental populations. This is true for Aborigines in Australia, Amerindians in Mexico, and Blacks in North America and South Africa. (See also my Personality and Individual Differences article on racial admixture in South Arica Testing the genetic hypothesis of group mean IQ differences in South Africa: Racial admixture and cross-situational consistency, 2008, PDF).
To achieve credibility, a theory must explain the totality of the phenomena. Only one theory does: hereditary differences in average IQ.
Philippe Rushton is a professor of psychology at the University of Western Ontario and the author of Race, Evolution, and Behavior: A Life History Perspective. This article adapted from a book review[Pay archive] that appeared in the July 2008 issue of the Elsevier Science journal Personality and Individual Differences.
(The Global Bell Curve: Race, IQ, and Inequality Worldwide is also available direct from the publisher.)