The OP is very interesting. Regarding the IQ of the different races, I think that IQ tests are strongly biased. For example, Bushmen have an average IQ of 54, whereas persons afflicted by Down Syndrome have an average IQ of 50. However, a person with Down Syndrome needs the supervision of an adult to carry on with his life. While, on the other hand, Bushmen, with almost the same average IQ, can survive on their own in one of the most adverse climates in the world. Do you see how stupid and biased IQ tests are? The brain of the Bushmen is adapted to their environment, not to the complex verbal and mathematical activities required to function in Western civilizations.