Sex at Dawn

Innately selfish or not, the effects of food provisioning and habitat depletion on both wild chimpanzees and human foragers suggest that Dawkins and others who argue that humans are innately aggressive, selfish beasts should be careful about citing these chimp data in support of their case. Human groups tend to respond to food surplus and storage with behavior like that observed in chimps: heightened hierarchical social organization, intergroup violence, territorial perimeter defense, and Machiavellian alliances. In other words, humans—like chimps—tend to fight when there’s something worth fighting over. But for most of prehistory, there was no food surplus to win or lose and no home base to defend.

In Search of Primate Continuity

Two elements women share with bonobos are that their ovulation is hidden from immediate detection and that they have sex throughout their cycle. But here the similarities end. Where are our genital swellings, and where is the sex at the drop of a hat?

FRANS DE WAAL¹²

Sex was an expression of friendship: in Africa it was like holding hands.... It was friendly and fun. There was no coercion. It was offered willingly.

PAUL THEROUX¹³

Whatever one concludes about chimp violence and its relevance to human nature, our other closest primate cousin, the bonobo, offers a fascinating counter-model. Just as the chimpanzee seems to embody the Hobbesian vision of human origins, the bonobo reflects the Rousseauian view. Although best known today as the proponent of the Noble Savage, Rousseau’s autobiography details a fascination with sexuality that suggests that he would have considered bonobos kindred souls had he known of them. De Waal sums up the difference between these two apes’ behavior by saying that “the chimpanzee resolves sexual issues with power; the bonobo resolves power issues with sex.”

Though bonobos surpass even chimps in the frequency of their sexual behavior, females of both species engage in multiple mating sessions in quick succession with different males. Among chimpanzees, ovulating females mate, on average, from six to eight times per day, and they are often eager to respond to the mating invitations of any and all males in the group. Describing the behavior of female chimps she monitored, primatologist Anne Pusey notes, “Each, after mating within her natal community, visited the other community while sexually receptive . They eagerly approached and mated with males from the new community.”¹⁴

This extra-group sexual behavior is common among chimpanzees, suggesting that intergroup relations are not as violent as some claim. For example, a recent study of DNA samples taken from hair follicles collected from chimpanzee nests at the Tai study area in Ivory Coast showed that more than half the young (seven of thirteen) had been fathered by males from outside the female’s home group. Were these chimps living in a perpetual war zone, it’s unlikely these females would have been free to slip away easily enough to account for over half their pregnancies. Ovulating female chimps (despite the heightened male monitoring predicted by the standard model) eluded their male protectors/captors long enough to wander over to the other groups, mate with unfamiliar males, and then saunter back to their home group. This sort of behavior is unlikely in a state of perpetual high alert.

Whatever the truth regarding relations between unprovisioned groups of chimpanzees in the wild, unconscious bias rings out in passages like this one: “In war as in romance, bonobos and chimpanzees appear to be strikingly different. When two bonobo communities meet at a range boundary at Wamba ... not only is there no lethal aggression as sometimes occurs in chimps, there may be socializing and even sex between females and the enemy community’s males.”¹⁵

Enemy? When two groups of intelligent primates get together to socialize and have sex with each other, who would think of these groups as enemies or such a meeting as war? Note the similar assumptions in this account: “Chimpanzees give a special call that alerts others at a distance to the presence of food. As such, this is food sharing of sorts, but it need not be interpreted as charitable. A caller faced with more than enough food will lose nothing by sharing it and may benefit later when another chimpanzee reciprocates [emphasis added].”¹⁶