How can you say "that's an unfair accusation." and then in the next line say "The other side just answer by accusing the others of being "racist"."
I agree that there is no consensus, and no evidence that clearly helps determine the truth here. That is why I said it was an "unanswered question" in GGP.
However, we do have some ability to reason about this. Clearly genetics can play a role in intelligence. We don't know if it does between humans, but we do know that it could. Humans are very abnormally (as successful species go) genetically similar, probably because of various population bottlenecks.
So, it could go either way. It is quite obvious to me that there is a very complex interaction between genetics and environment. Some populations benefit from breast feeding, other populations do not. This is genetic. There are clearly some hereditary differences which have a measurable consequence in brain development. To what extent do these explain that one random person might be an idiot, while another might be a genius? I honestly don't know, but we shouldn't shut down debate.