>>13
The problem with intelligence testing is that it's essentially impossible to remove social interactions and say that there is a basic biological difference between groups.
It's more plausible to say that black U.S. Americans and African natives under-perform in areas of intelligence because of economic disparity brought on by the artifacts of colonialism and modern-day capitalism engines (i.e. propping up dictators who prove rare-metal exports.)
Areas looking into the human genetic variation find that the
whole of humanity has an incredible unvarying set of characteristics- as a whole we have less variation as a species than a few dozen in-group chimp.
And, there are greater individual differences within racial groups than between racial groups (however you decide to draw the lines.)