Of course, when discussing "nature" in this context, it is always between two humans. Why, how's the nature/nurture debate between humans and skunk cabbage going? Of course, nature is highly determinant there. When you compare a very stupid human, and a very intelligent human, you are in an absolute sense comparing two extraordinary creatures whose extraordinariness is wholly genetic. Their itty-bitty differences (auto mechanic vs. auto engineer) are how we measure ourselves in a power-spectrum and skew our perceptions.

It doesn't matter: Private sector eugenics is already emerging and will settle all bets.