Origins of Race Differences
Racial differences exist at a more profound level than is normally considered. Why do Europeans average so consistently between Africans and Asians in crime, family system, coïtusual behavior, testosterone level, intelligence, and brain size? It is almost certain that genetics and evolution have a role to play. Transracial adoption studies indicate genetic influence. Studies of Korean and Vietnamese children adopted into white American and white Belgian homes showed that, although as babies many had been hospitalized for malnutrition, they grew to excel in academic ability with IQs ten points higher than their adoptive national norms. By contrast, Sandra Scarr and her colleagues at Minnesota found that at age 17, black and mixed-race children adopted into white middle-class families performed at a lower level than the white siblings with whom they were raised. Adopted white children had an average IQ of 106, an average aptitude based on national norms at the 59th percentile, and a class rank at the 54th percentile; mixed-race children had an average IQ of 99, an aptitude at the 53rd percentile, and a class rank at the 40th percentile; and black children had an average IQ of 89, an aptitude at the 42nd percentile, and a class rank at the 36th percentile.
No known environmental variable can explain the inverse relation across the three races between gamete production (two-egg twinning) and brain size. The only known explanation for this trade-off is life-history theory. A life-history is a genetically organized suite of characters that evolved in a coordinated manner so as to allocate energy to survival, growth, and reproduction. There is, in short, a trade-off between parental effort, including paternal investment, and mating effort, a distinction Patricia Draper referred to as one between "cads" and "dads."
Evolutionary hypotheses have been made for why Asians have the largest brains and the most parenting investment strategy. The currently accepted view of human origins, the "African Eve" theory, posits a beginning in Africa some 200,000 years ago, an exodus through the Middle East with an African/non-African split about 110,000 years ago, and a Caucasoid/Mongoloid split about 40,000 years ago. Evolutionary selection pressures are different in the hot savanna where Africans evolved than in the cold arctic where Asians evolved.
The evidence shows that the further 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. The evolutionary sequence fits with and helps to explain how and why the variables cluster. As the original African populations evolved into Caucasoids and Mongoloids, they did so in the direction of larger brains and lower levels of coïtus hormone, with concomitant reductions in aggression and coïtusual potency and increases in forward planning and family stability.
Despite the vast body of evidence now accumulating for important genetic and behavioral differences among the three great macro-races, there is much reluctance to accept that the differences in crime are deeply rooted. Perhaps one must sympathize with fears aroused by race research. But all theories of human nature can be used to generate abusive policies. And a rejection of the genetic basis for racial variation in behavior is not only poor scholarship, it may be injurious to unique individuals and to complexly structured societies. Moreover, it should be emphasized that probably no more than about 50 percent of the variance among races is genetic, with the remaining 50 percent due to the environment. Even genetic effects are necessarily mediated by neuroendocrine and psychosocial mechanisms, thus allowing opportunity for benign intervention and the alleviation of suffering.