[Paradox]

Its probably a bit of both. Genetics is a much stronger factor than most people would like to think, but regardless of that, nutrition and intellectual environment play a huge role as well.

I know its uncomfortable to think about, but the genetic/physical link to intelligence is real, and it is Strong. It bothers people on both sides of the political isle, for different reasons.

[Reeses]

nutrition and intellectual environment play a huge role as well

How many parents know that on average children raised in a big city grow up smaller and have more health problems than those that grow up in the countryside? That's been known for some time but the truth is suppressed due to country children more likely to turn into Republican voters, even if they later move to a big city. While the Democrat bell curve is wider, the average Republican is both taller and smarter than the average Democrat. You'll never hear that truth from the urban media.