Bonobos play in their enclosure at Planckendael zoo in Mechelen, Belgium.Francois Lenoir / Reuters

If you’ve read National Geographic or seen a documentary about chimps, you’ve heard that we can learn a great deal about ourselves from our very close primate relatives Pan troglodytes.

Observing a troop in Gombe, Tanzania, Jane Goodall discovered that chimps have personalities, intimate relationships, and agendas. Her work and that of scientists who followed in her footsteps also taught us that chimps are a male-dominant species, prone to not-infrequent violence, with males harassing and sexually coercing lower-ranking female troop members. Aggression, many primatologists, academics, and  nonexperts extrapolate from our body of knowledge about chimps, is in our “nature,” as is the dynamic of males attempting to control and dominate females with physical attacks, forced copulation, and even infanticide. Harvard primatologist Richard Wrangham, a chimp guy, famously asserted in Demonic Males that we humans are living out “a continuous, five-million-year habit of lethal aggression,” driven by a male will to dominate strangers and females. We can expect male dominance and male sexual coercion of females, we’ve been taught, because we’re “wired” that way.

But our wiring looks less nasty, brutish, and bro-y if we throw over chimps in favor of another close primate relative, the bonobo.

On a sunny March day in 2016, I stood at the bonobo enclosure of the San Diego Zoo, observing several Pan paniscus performing what struck me as an upside-down, inside-out passion play about gender, power, and aggression.

Amy Parish—a primatologist and self-described Darwinian feminist who has been studying the species for some 30 years—was looking through the enormous windows with me and explaining the finer points of being bonobo. “Everyone knows them as the free-love, sexy apes,” she observed as the troop of nine crossed the verdant enclosure, bisected by a small “stream.” Two younger bonobos climbed up and hung from the bamboo-and-rope sway structures; others flopped onto a rock outcropping to sun themselves. A male groomed a nearly bald female.

At first glance, bonobos look a lot like chimps, just taller and slimmer, with smaller heads and ears. But unlike chimps, whose modus operandi is to duke it out under stress, bonobos “consort” when they come upon food, or when they encounter a new troop of bonobos, or whenever they feel the need to dispel tension and cement social bonds.

And how. In the wild and in captivity, bonobos appear to have sex all the time, with just about anyone. Their sexcapades are not just casual and seemingly indiscriminate; they are remarkably creative. The anthropologist Meredith Small describes watching bonobo sex as “like watching humans at their most extreme and perverse.”

Notably, bonobo females approached by a female and a male simultaneously for sex (it happens) tend to choose girl-on-girl action. Lying one on top of the other or side to side, they press and grind their vulvas together, often shrieking. Their clitorises—richly innervated, larger than a human female’s, and more externalized—probably explain why female bonobos so eagerly practice genito-genital, or G-to-G, contact. It feels good, possibly even better than intercourse with a male.

Female pleasure is central to bonobo society. Early in her career, Parish noticed that female bonobos get groomed a lot more than males do, and that the females eat first. Based on these two indicators of dominance, she began to suspect that bonobos were very different from chimps, long considered the best template for understanding the evolutionary origins of human sexual and social behavior. “Male bonobos are not aggressive toward females, and we don’t see infanticide, or females being sexually coerced,” Parish told me.

Female bonobos are, however, known to attack males, swatting, gouging, smacking, and biting those that cross or merely annoy them. Parish described a male bonobo in Frankfurt with only eight digits intact, and another male that had had its penis nearly severed. Intrigued, Parish looked at zoo veterinary records and discovered that more than 95 percent of serious injuries were inflicted on males by females. Bonobos, Parish realized, are a female-dominant species.

As we stood there watching the bonobos lounge peacefully that sunny day, Parish also told me about an even more sinister side to male-female bonobo relations. Females often initiate sex with males, and the males are often receptive. But sometimes an unenthusiastic male may try to shake off a female, to little avail. A female may “solicit” such a male again and again, putting her arms around him repeatedly as he attempts to slip away, refusing to be refused. Eventually, they have sex.

“The situation of male-female sex sometimes looks coercive to me,” Parish observed as I hung on to her words, stunned to hear what she was telling me: Female bonobos force males to have sex with them against their will. This is not difficult to do, she pointed out, since the males frequently have erections from the anxiety of being dominated and coerced. During the sex, she elaborated, males may give distress vocalizations and attempt to escape.

The head primate zookeeper confirmed that he and others had observed the same. Female bonobo sexual assertiveness, he explained, “is in your face. You can’t ignore it.”

What gives female bonobos all this power? To eat first, be groomed, coerce males, and rule the roost in general? Parish believes that it’s the lesbian sex. G-to-G rubbing feels so good it bonds female bonobos, allowing them to create formidable coalitions. This in turn gives them the upper hand in matters across the board. In fact, an adult male bonobo is likely to run to Mom when in a dire situation—because among bonobos, it’s females who are alphas and whose support is critical.

Bonobos live in what we might think of as a matriarchal hookup culture, one that not only poses no danger to females, but also knits them into authoritative posses. Does that mean female-on-male sexual control is “inherent” to human nature? Of course not. But it does suggest that male-on-female sexual control isn’t inevitable or natural either. Chimps provide one model; bonobos, which some researchers believe are even more closely related to us than chimps, provide another. Think of that the next time you hear sexual coercion dismissed as a deeply programmed, essentially human behavior. Or see a male primate snarl aggressively on TV, in a rage because he’s been called to answer accusations that he sexually coerced a female.

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