I think nutrition has a lot to do with with. Go to many impoverished nations and their 15 year olds are the size of our 8 year olds.
I've also read studies that suggest the added protein in our diets from when our ancestors discovered how to hunt, led to greater brain growth and cognitive development in humans. Our intelligence increased marginally in a short period of time.
__________________
"A pessimist thinks things can't get any worse. An optimist knows they can."
|