I prefer the counter-argument.
'But just because humans have more mutations in their intelligence genes doesn't mean we are becoming less brainy as a species, said psychologist Thomas Hills of the University of Warwick, who was not involved in the study. Instead, removing the pressure for everyone to be a superb hunter or gatherer may have allowed us to evolve a more diverse population with different types of smarts, he said.
"You don't get Stephen Hawking 200,000 years ago. He just doesn't exist," Hills told LiveScience. "But now we have people of his intellectual capacity doing things and making insights that we would never have achieved in our environment of evolutionary adaptation."'