Comment This is Testable (Score 1) 637
This idea should be easy to test, statistically speaking. If he's right, then the populations with the worst mental degradation and more emotional instability should be found in those parts of the world where civilization first took root, while those populations who lived as hunter-gatherers until relatively recently (or even up to the present day!) should have a big intellectual advantage.
I am not aware of any such effect being measured and documented.