Just look at all the amazing innovations modern technology has given us: at-home HIV tests, motion-activated screwdrivers and self-inflating tires. It’s easy to look down on our prehistoric ancestors for their primitive, electric screwdriver-less way of life. But one scientist says we shouldn’t be so quick to judge.
In a two-part paper published in the journal Trends in Genetics, Stanford University researcher Gerald Crabtree suggests that evolution is, in fact, making us dumber — and that human intelligence may have actually peaked before our hunter-gatherer predecessors left Africa.
The reason? Life on the veldt was tough, and prehistoric humans’ genes were constantly subjected to selective pressure in an environment where the species’ survival depended on it. For humans, that meant getting smarter. ”The development of our intellectual abilities and the optimization of thousands of intelligence genes probably occurred in relatively non-verbal, dispersed groups of peoples before our ancestors emerged from Africa,” Crabtree said in a news release.