|
As everyone else says, nature is huge. Subtle difference in brain chemistry can make a big difference even among close relatives, and those can be affected both by genetics and by the fetal environment. They can _also_ be affected by experiences in the world: I've read that the brain of an early-adolescent boy who is bullied a lot will develop differently than it might if he was in a safer situation, and those changes will affect his behavior just as much as the unpleasant memories.
So, it's nature and nuture and nature-as-modified-by-nuture.
|