Chimpanzees and bonobos are humans' closest biological relatives, sharing roughly 98 percent of our genome, so it makes sense that we'd share a few behavioral traits. Chimps' power struggles may be louder and rowdier than Senate hearings and town-hall meetings, but not by much.

 

And while there aren't formal elections in chimp society, no alpha male can rule for long without support from a key voting bloc: females. "The male has to be accepted by the females before he can gain his status," according to the Institute for the Study of Human-Animal Relationships. "Females can be very choosy, and if the females do not approve of the alpha male they will not let him mate with them." After that happens, he may soon be overthrown by a rival male.