It is contrary to current perceived wisdom to say that a person is incapable of this or that or more likely to be capable of this or that simply by reason of their racial origin. I wonder what Hans thinks of Jews, Poles, Gypsies, the Irish, Asians and Orientals. I am fairly shocked by his bare-faced assertion that Africans are somehow inferior, and I thought I remembered that Eysenk and more recent scientists who had proposed that some races were more or less intelligent than others had been refuted (in the true sense of the word)
Nonetheless it is a fact that the Inuit are more likely to be short, and Nilotics (but not Bushmen) to be tall. It isn't so long ago that in the USA Jews were widely thought to be inherently better dancers and sportsmen than non-Jews. Assumptions that I made in the 60s and 70s that differences in behaviour between men and women were due solely to nurture and not to nature are not so widely accepted today.