I wouldn't be surprised if skin colour made a difference to IQ. But I wouldn't be surprised for social and political reasons, not genetic ones.

It's actually not possible to make a genetic argument, because genetically there are no non-trivial markers that robustly correlate with "black" or "white."

http://web.mit.edu/racescience/in_media/what_dna_says_about_...

Suggesting otherwise is simple ignorant bigotry.