@8bagels - the plural of anecdote is not “data.”
And this:
Is not a refutation.
Seriously. There is a TON of research on “intelligence” and its genetic components, and the knee-jerk answers some of you seem so eager to propound are not supported by the research. Get a JSTOR or Lexis-Nexis account and do some searching. It’s a huge and varied field, and I assure you any “easy” answer is false.