this is a bullshit, reductionist argument that fails to take into consideration that the set of traits tested for in IQ and other intelligence tests are often of no use in a completely different environment. The artificial context created by the tests themselves are not easily mapped onto (or replicated in) real world situations
I disagree. But whatever it is they are gauging, and whichever imperfections they are encumbered with, they are still important in so far as a great many people clearly find them a useful indicator of mental dexterity.
Here is the report I shall be referring to henceforth. It is a compilation of recent years’ most important scientific findings on the subject; it also forms the basis for the
Slate series. A lot of text, but this is as good a summary as you are likely to get of the
hereditarians’ position on the subject.
On Race
Some have argued that the cause of Black–White differences in IQ is a pseudo question because “race” and “IQ” are arbitrary social constructions (Tate & Audette, 2001). However, we believe these constructs are meaningful because the empirical findings documented in this article have been confirmed across cultures and methodologies for decades. The fuzziness of racial definitions does not negate their utility. To define terms, based on genetic analysis, roughly speaking, Blacks (Africans, Negroids) are those who have most of their ancestors from sub-Saharan Africa; Whites (Europeans, Caucasoids) have most of their ancestors from Europe; and East Asians (Orientals, Mongoloids) have most of their ancestors from Pacific Rim countries (Cavalli-Sforza, 2000; Cavalli-Sforza, Menozzi, & Piazza, 1994; Nei & Roychoudhury, 1993; Risch, Burchard, Ziv, & Tang, 2002). Although he eschewed the term race, Cavalli-Sforza’s (2000, p. 70) maximum likelihood tree made on the basis of molecular genetic markers substantially supports the traditional racial groups classification. Of course, in referring to population or racial group differences we are discussing averages. Individuals are individuals, and the three groups overlap substantially on almost all traits and measures. [...] (p. 237 f)
[...] The currently most commonly accepted view of human origins, the “Out-of-Africa” theory, posits that Homo sapiens arose in Africa about 150,000 years ago, expanded northward beyond Africa about 100,000 years ago, with a European–East Asian split about 41,000 years ago (Cavalli-Sforza et al., 1994; Stringer & McKie, 1996). In Cavalli-Sforza’s (2000) maximum likelihood tree devised on the basis of molecular genetic markers, the most distant group was the Africans, with Europeans and Asians being closer. Cavalli-Sforza observed, “All world trees place the earliest split between Africans and non-Africans, which is expected given that all humans originated in Africa” (p. 72). This is also the conclusion of other reviewers (e.g., Risch et al., 2002).
Evolutionary selection pressures were different in the hot savanna where Africans lived than in the cold northern regions Europeans experienced, or the even colder Arctic regions of East Asians. These ecological differences affected not only morphology but also behavior. It has been proposed that the farther north the populations migrated out of Africa, the more they encountered the cognitively demanding problems of gathering and storing food, gaining shelter, making clothes, and raising children successfully during prolonged winters (Rushton, 2000). As these populations evolved into present-day Europeans and East Asians, the ecological pressures selected for larger brains, slower rates of maturation, and lower levels of testosterone—with concomitant reductions in sexual potency, aggressiveness, and impulsivity; increases in family stability, advanced planning, self-control, rule following, and longevity; and the other characteristics listed in Table 3. The fact that the three-way pattern in IQ, brain size, and other traits is not unique to the United States but occurs internationally is consistent with a single, general (genetic–evolutionary) theory, whereas culture-only theory must invoke a number of highly localized, specific explanations.
As Homo sapiens migrated further away from Africa, the random genetic mutations that occur at a constant rate in all living species accumulated, along with the adaptive changes. The resulting differences in allele frequencies are sufficient for numerous and extensive genetic investigations to yield essentially the same picture and identify the same major racial groupings as did the morphological markers of classical anthropology. The greatest genetic divergence within the human species is between Africans (who have had the most time for random mutations to accumulate) and non-Africans (Cavalli-Sforza 2000; Cavalli-Sforza et al., 1994; Nei & Roychoudhury, 1993). Jensen (1998b, pp. 517–520) carried out a principal-components analysis of data on genetic markers from Nei and Roychoudhury (1993) and found the familiar clustering of races: (a) East Asians, (b) Europeans and East Indians, (c) South Asians and Pacific Islanders, (d) Africans, (e) North and South Amerindians and Eskimos, and (f) Aboriginal Australians and Papuan New Guineans. Howells’s (1993) analysis of betweengroups variation in craniometric data also revealed a similar population tree. The genetic hypothesis is consistent with the latest findings on human origins and genetic variation, whereas culture-only theory is indifferent to them (Crow, 2002). (p. 265 f)