Race is a proxy for genetics. It is a good way of describing groups of people. I don't think there is anything about having black skin that makes one dumb. I do think that people who have black skin are less intelligent. That black skin is a purely cosmetic way of describing a population of people who are generally related does not dismiss its usefulness to divide the human race. Races are essentially a heuristic. In other words, one can be a race realist while still understanding that it is not all that useful in the field of biology.