It's both environmental and genetics.
Why haven't certain civilizations contributed anything useful? A lot of things have come from Greece, North Africa, Europe, India, China and even the polynesians. The west is easily on top these days and I don't think as a whole some people will be able to catch whitey; genes and environment being the factors.
What's come out of western africa?
Why are some people there like 2,000 years behind?
It ain't poltically correct, but it's the truth.
IMO, IQ is hard to measure for developing nations.. I mean someone who's not fed can't develop a fucking brain to do algebra and learn to read and write.
(In the time of the British Raj) Wasn't there some indian guy who got ahold of a british algebra book, but was totally uneducated in the laws of math prior, but wrote like complex equations and stuff after reading the book? This was back during the british raj, and I can't recall his name.. He was supposedly poor and had no educational background, yet he learned complex math on his own. He was mentioned in the movie Good Will Hunting, I think. Anyone hear of him? I'm mentioning him because that shows how genes can overcome certain enviornmental factors.