To the best of my knowledge, there exists absolutely no scientific evidence today in favor of any statistically significant genetic difference in mental abilities across races. Yet, I do not think we understand genetics well enough to absolutely rule out such a possibility. So I do not rule out the possibility that African Americans, are, on average, genetically predisposed to be less intelligent. In fact, I do not rule out this possibility for any race — Whites, South Asians, Mongoloids, Eskimos.
My position on the matter is identical to Eugene Volokh’s. “Whether there are genetic differences among racial and ethnic groups in intelligence is a question of scientific fact. Either there are, or there aren’t (or, more precisely, either there are such differences under some plausible definitions of the relevant groups and of intelligence, or there aren’t). The question is not the moral question about what we should do about those differences, if they exist. It’s not a question about what we would like the facts to be. The facts are what they are, whether we like them or not.”
The same is true for other group classifications, such as gender. In fact, according to noted Harvard psychologist Steven Pinker and many other experts, there is fairly good evidence of differences in mental abilities between males and females. For certain mental tasks it appears that males, on average, are genetically better equipped; for certain others, females are.
What is important is this: Even if some differences in mental ability exists across groups, given the extremely large variation between individuals in any group, these differences are irrelevant from a moral or legal standpoint. It is not racist or sexist to suggest or believe that differences exist on average; it is racist and sexist to suggest we should treat people differently purely because they belong to a certain group.
What is even more important is this: The culture of pervasive political correctness today that makes is impossible to ask such questions without facing a huge backlash and social ostracization is stifling to intellectual curiousity, degrading to our intelligence and speaks only ill of our open-mindedness; in short like everything else associated with political correctness it is evil.