Evolution may have less to do with rising above one’s peers than learning to get along with more of them. Bigger groups of primates survived better, but required an increase in their ability to remember everyone. Complicated brains make for more complex societies. The more advanced the primate, the bigger its social groups. “It’s not a qualitative difference but a quantitative one,” he says, and it’s part of what makes humans human.  

A quarterback, point guard, or midfielder, no matter their skills, is only as valuable as their ability to coordinate with the other players; A great athlete is one who can predict the movements of the most players at the same time. primates were held back less by their size or skills than by their social intelligence. Developing bigger brains allowed human beings to maintain a whopping 150 stable relationships at a time.