Basic human sex differences parallel those observed in chimpanzees, such as higher energy and aggression in males.

“Uh, so when I spent time with the chimps, I was really blown away by the ways that the sex difference in the sex differences in the chimps paralleled human sex differences. Of course, not exactly the same, but the very basic things that you just described um, even just in terms of energy and aggression are present in the chimps in terms of being higher in the males and lower in the females.”