Sex at Dawn

Nicolaes Tulp, a well-known Dutch anatomist immortalized in Rembrandt’s painting The Anatomy Lesson, produced the earliest accurate description of a nonhuman ape’s anatomy in 1641. The body Tulp dissected so closely resembled a human’s that he commented that “it would be hard to find one egg more like another.” Although Tulp called his specimen an Indian Satyr, and noted that local people called it an orangutan, contemporary primatologists who have studied Tulp’s notes believe it was a bonobo.

Like us, chimps and bonobos are African great apes. Like all apes, they have no tail. They spend a good part of their lives on the ground and are both highly intelligent, intensely social creatures. For bonobos, a turbocharged sexuality utterly divorced from reproduction is a central feature of social interaction and group cohesion. Anthropologist Marvin Harris argues that bonobos get a “reproductive payoff that compensates them for their wasteful approach to hitting the ovulatory target”The payoff is “a more intense form of social cooperation between males and females” leading to “a more intensely cooperative social group, a more secure milieu for rearing infants, and hence a higher degree of reproductive success for sexier males and females.”³ The bonobo’s promiscuity, in other words, confers significant evolutionary benefits on the apes.

The only monogamous ape, the gibbon, lives in Southeast Asia in small family units consisting of a male/female couple and their young—isolated in a territory of thirty to fifty square kilometers. They never leave the trees, have little to no interaction with other gibbon groups, not much advanced intelligence to speak of, and infrequent, reproduction-only copulation.

Monogamy is not found in any social, group-living primate except—if the standard narrative is to be believed—us.

Anthropologist Donald Symons is as amazed as we are at frequent attempts to argue that monogamous gibbons could serve as viable models for human sexuality, writing, “Talk of why (or whether) humans pair bond like gibbons strikes me as belonging to the same realm of discourse as talk of why the sea is boiling hot and whether pigs have wings.”⁴

Primates and Human Nature

If Thomas Hobbes had been offered the opportunity to design an animal that embodied his darkest convictions about human nature, he might have come up with something like a chimpanzee. This ape appears to confirm every dire Hobbesian assumption about the inherent nastiness of pre-state existence. Chimps are reported to be power-mad, jealous, quick to violence, devious, and aggressive. Murder, organized warfare between groups, rape, and infanticide are prominent in accounts of their behavior.

Once these chilling observations were published in the 1960s,

theorists quickly proposed the “killer ape” theory of human

origins. Primatologists Richard Wrangham and Dale Peterson

summarize this demonic theory in stark terms, finding in

chimpanzee behavior evidence of ancient human blood-lust,

writing, “Chimpanzee-like violence preceded and paved the

way for human war, making modern humans the dazed

survivors of a continuous, 5-million-year habit of lethal 5

aggression.

Before the chimp came to be regarded as the best living model of ancestral human behavior, a much more distant relative, the savanna baboon, held that position. These ground-dwelling primates are adapted to the sort of ecological niche our ancestors likely occupied once they descended from the trees. The baboon model was abandoned when it became clear that they lack some fundamental human characteristics: cooperative hunting, tool use, organized warfare, and power struggles involving complex coalition-building. Meanwhile, Jane Goodall and others were observing these qualities in chimpanzee behavior. Neuroscientist Robert Sapolsky—an expert on baboon behavior—notes that “chimps are what baboons would love to be like if they had a shred of self-discipline.”⁶

Perhaps it is not surprising, then, that so many scientists have assumed that chimpanzees are what humans would be like with just a bit less self-discipline. The importance of the chimpanzee in late twentieth-century models of human nature cannot be overstated. The maps we devise (or inherit from previous explorers) predetermine where we explore and what we’ll find there. The cunning brutality displayed by chimpanzees, combined with the shameful cruelty that characterizes so much of human history, appears to confirm Hobbesian notions of human nature if left unrestrained by some greater force.

Table 1: Social Organization Among Apes

Egalitarian and peaceful, bonobo communities are maintained primarily through social bonding B_onob_obetween females, although females bond with males as well. Male status derives from the mother. Bonds between son and mother are lifelong. Multimale-multifemale mating.