There is one argument against the claim that the distribution of intelligence is different by race or gender that I have very rarely seen and have not discussed here ?" the claim that since there is no advantage to being stupid there is no reason why evolution would produce any stupid people. The obvious problem with it is that, race and gender aside, stupid people exist. But that raises the question of this post. Being smart is a good thing, it is possible to be smart ?" some people are ?" so why isn't everybody? I see three possible sorts of explanation.