Sublime

If you spend time with the primates closest to human beings, you’ll see female chimps having intercourse dozens of times per day, with most or all of the willing males, and rampant bonobo group sex that leaves everyone relaxed and maintains intricate social networks.

If we compare gibbons, which are monogamous, with baboons, which are not, we see that baboons have marked sexual size dimorphism and enlarged canines. Polygyny—which is associated with strategies two and three from the previous chapter—leads inexorably both to male-male violence and to the morphology that enables that violence.