Small Brain and Racism

I just read in the NYT an interview with an English zoologist.  He says something I've understood reading Richard Dawkins book, "The Ancestor's Tale." It is not true that evolution has an end product, and it is us.

The good brain, is the fit brain.

Now the racism part.

Imagine you move in a place where human beings had little competition and they have little brains. Will you teach complex behavior?

America is smaller than Eurasia. Are  Americans less capable of competing in mathematics, with say, Ashkenazim Jews?

I don't know if I want to go that path, given that I have Amerindian students.