All my statements above are about population averages. Some ignorant people (I certainly don't mean you) don't understand that population averages apply to populations, and not to individuals. For example, women are shorter than men, on average, but there are millions of women that are taller than me. Native Americans tend to have a lot of trouble with alcohol (for very simple genetic reasons). On the other hand, many don't. Africans have invested a lot of evolutionary effort into malaria resistence. Sometimes they get it anyway. Europeans have invested in lactose tolerance. My dad can't drink milk. Unsuprisingly brain genes (check out Lahn's papers on ASPM and microcephalin in Mol. Gen.) differ between population groups as well. That doesn't say much about any given individual. It does say a lot about groups.