ISIS on the offensive in Iraq

[Husar]

IIRC around 30-50% of your intelligence are decided in very early childhood when most of the basic links between brain cells are formed.
That has nothing to do with genetics, it's mostly about stimuli and those are probably more related to culture and other circumstances that children grow up in, certainly how much the parents explain to their children, show them the world and allow them to experiment and learn.

One doesn't just get born with a set of brain connections that make one stupid or clever, that's not how a brain works.