How do chimpanzees recognize each other?

Humans recognize others by their faces. And yes, chimpanzees can do that. But they also recognize each other by looking at their anogenital areas, their butts. Rear ends serve a big purpose in the chimp world. Bottoms and faces are both symmetrical, and interpreting what a behind is saying is crucial to chimpanzees’ reproductive success, just as interpreting facial messaging is important to human mating. Recognizing and reading other chimps’ backsides also helps prevent inbreeding.