He found that the larger the primate’s neocortex, the larger the communities it formed. It takes a lot of brain to process all of the relationships in a complex society, you see. When primates find themselves in groups larger than what their brains can handle, the system breaks down. Factions form. Wars break out. Now, and do pay attention, because this is crucial—you can actually look at a primate brain and, knowing nothing else about what species it came from, you can predict how big their tribes are.”
