I question the genetic component to all of the differences. The brain molds itself to experiences, so if you grow up in a world of books you'll learn to think, or in a forset you'll learn to hunt and gather. genetics might give you a 1-2% head start, but as far as success, I don't think that's enough to really make a difference. Most jobs even in the industrial world are pretty much idiot proof. You don't need to re-invent the wheel.
Culture on the other hand -- gods yes. If you think crime is good and school is bad, you won't go anywhere.