Why Are Bonobo Apes Having Sex All the Time?

Frequent genito-genital rubbing. Incessant intercourse, enacted in a surprising number of ways with impressive acrobatics and adroit body control. Complete integration of erotic activity into everyday life. Ah, to be a bonobo.

Bonobos, a species of great apes also known as Pan paniscus, have a reputation for being rather libertine. Not unrelated, lethal violence is effectively unheard of among these hominids. There's no clear-cut, confirmed case of a bonobo killing another bonobo in the wild.

Unfortunately, humans and chimpanzees have a far bloodier track record than our erotically inclined brethren.

It’s an all-day, everyday orgy

As Frans de Waal points out in his new book, "Different: Gender Through the Eyes of a Primatologist," we share at least 96 percent of our DNA with bonobos and chimps—though the exact number is still contested—and we share our socioemotional makeup with them, too.

"Chimpanzee society is aggressive, territorial and run by males," writes de Waal, a biologist who lives in Georgia. "Bonobos are peaceful, sex-loving and female-dominated. How much more unalike can two apes get?"

Homo sapiens genetically split off from shared hominid ancestors about 6 million years ago, he noted, while bonobos and chimps diverged about 4 million years after that, making humans comparably close to—but, of course, appreciably different from—both species.

Bonobos, located in the Democratic Republic of Congo as well as several sanctuaries and zoos across the world, have learned how to do a number of tasks many people might assume are uniquely human.

'In bonobos, it's public. It's promiscuous.'

Kanzi, age 41, a legendary bonobo perhaps capable of comprehending spoken English and communicating with people via lexigram, has repeatedly disabused humans of anthropocentric hubris. In 2010, he showed off his language skills on "Oprah" and, true to his bonobo nature, reportedly made a pass at show correspondent Lisa Ling. These days, he puts paint to canvas to create artwork at the Ape Initiative in Des Moines, Iowa, where one of his works recently sold for $500.

If bonobos can learn from human behavior, perhaps we can take a page from the bonobo playbook. According to de Waal, the bonobos have a vast sexual repertoire and "mate in every conceivable posture, including some that we're incapable of, such as hanging upside down by their feet."

Susan Block, Ph.D., reigning "Sexologist of the Year," courtesy of the 2021 Glenny Awards created by "Sex in the Pews" podcast host Glenn Klein, clearly thinks humans can learn from bonobos. In her book, "The Bonobo Way: The Evolution of Peace Through Pleasure," the Los Angeles-based Block writes that a bonobo-inspired approach to life "offers an alternative great ape paradigm for human behavior, especially (but not exclusively) sexual behavior."

She encourages individuals to take on what she calls the "bonobo liberation challenge" to break through inhibitions, turn shame into an aphrodisiac and unleash one's "inner bonobo" to co-produce carnal and primal primate knowledge.

But what's the basis of that knowledge among bonobos and to what degree can their way of life inspire us?

The art of GG rubbing

"In bonobos, it's public. It's promiscuous," said Martin Surbeck, Ph.D., an assistant professor in the department of human evolutionary biology at Harvard University, describing the bonobos' attitudes toward sex.

As with humans, sexual relations among bonobos are more nuanced than raunchy mental images of omnipresent great ape orgies. Female bonobos, for example, please each other often with a same-sex practice that appears to serve several functions.

"It's called genito-genital rubbing, or GG rubbing, and they embrace and rub their genital swellings together," said Kirsty Graham, Ph.D., of Scotland, who has studied bonobos for about a decade, focusing on how they communicate using gestures.

Graham added that female chimps don't engage in GG rubbing quite the way female bonobos do—and certainly not with the same frequency.

"There's often this view that bonobos are having way more sex than any of the other great apes, but I think that's a reflection of how often the females GG rub," Graham said.

All nonhuman great ape females experience genital swelling, but with bonobos, there's some partial swelling pretty much all the time, though full distension occurs based on monthly cycles.

"When female bonobos have their maximum monthly swelling, they GG rub the most and other females will seek them out and GG rub with them," she added.

'Rather than sex serving primarily reproductive purposes, it seems to facilitate tolerance, which can encourage sharing of food and help with tension regulation.'

"It seems to be particularly prominent during times of higher tensions," Surbeck said.

According to Surbeck, GG rubbing often occurs when female bonobos approach feeding trees and there's potential for conflict, which is also when male-female copulation often occurs, probably for similar reasons. GG rubbing also happens when a female bonobo becomes irritated and urgently seeks out another, ostensibly for release. Rather than sex serving primarily reproductive purposes, it seems to facilitate tolerance, which can encourage sharing of food and help with tension regulation.

'They frantically rub their clitorises together'

"What we see in these same-sex, social-sexual behavior is [there] seems to be an increase in oxytocin that physiologically seems to facilitate bonding and also tolerance between certain individuals, which allows for more cooperation and other things," Surbeck added.

In "Different," de Waal writes that anybody who observes "two female bonobos in the midst of intense GG rubbing will agree that it looks extremely enjoyable. The females bare their teeth in a grin and utter piercing squeals as they frantically rub their clitorises together while staring into each other's faces."

Graham said researchers have posited a number of hypotheses about why bonobos GG rub—because they discovered a tree with delicious fruit, after a fight or when they encounter other groups of bonobos—with a focus on social bonding and stress relief. Those explanations aren't wrong per se, but she noted it's interesting that so much literature treats GG rubbing as "this mysterious social behavior that just happens to be with the genitals" and as some "puzzle of like, 'Why would these females be rubbing their genitals together,' and none of them include 'because it feels good.'"

In his new book, De Waal explains that a female bonobo carries "a soccer-ball-size pink signal on her behind that tells every male in the neighborhood that she's ready for action. The males are extremely interested in those behinds."

Unlike the female chimpanzee, who advertises only when she's ovulating, the genitals of female bonobos swell at other times, too, such as when they're pregnant and lactating. Surbeck said male bonobos reduce aggression against females when the genitals of females are supremely swollen.

"Maybe these changes in sexuality that we see in bonobos—this prolonged period of sexual attractiveness—is linked to gain in leverage and gain in power of individual females," he suggested.

The power of female coalitions

If a female bonobo and a male bonobo are both placed in a zoo together on their own, the male—with his larger size, superior strength and canine teeth (which females lack)—typically dominates.

"The male is definitely better equipped for fighting than the female," de Waal explained in an interview with Giddy. "But as soon as you add a second female, that ends because the two females will immediately band together and they will keep that male under control. And, of course, in a normal group, you have more than two females."

A clique often surrounds the alpha female, he added. Together, they monopolize control and allocation of food and determine travel direction, important factors in the forest.

"The females have a big effect on the hierarchy among the males," de Waal said. "The males are very dependent on their mothers."

Well into adulthood, male bonobos continue to rely on their moms, who provide protection and can confer status. A high-ranking female is more likely to have higher-ranking sons, according to de Waal, and when their mothers die, males can lose their status.

"The females have an enormous say in the bonobo society, and the females are very aware of their collective power," he added. "That's also a reason why the females always stick together."

East African female chimps don't form coalitions like bonobos do, Graham said. Coalition formation among male bonobos is similarly rare compared to alliances among male chimps.

Chimpanzees are prone to lethal violence, but unlike bonobos, chimp cooperation remains the default trait. Surbeck said strong cooperation within a group of male chimps is also used against out-groups of other males they encounter.

Some humans—men, in the main—might scoff at sexual and gender relations among bonobos, given the collective power of the "Bonobo Sisterhood," as it's sometimes called, though the coalitions comprise mostly unrelated females.

"I'm not sure what to do with that because the bonobo male, first of all, has an enormous amount of sex with a lot of females, so that seems like a good thing, you would think," de Waal said. "And second, the hierarchy—also in humans, I would say—is mostly within gender. So the males worry about their position with other males. 'Am I at the top or am I at the bottom?' That matters to them. But the dominance over females or the dominance by females, that's a sort of secondary issue."

Alliances help female bonobos counteract male aggression and curb violence, Surbeck said. But as with other primates, relations between the sexes aren't always smooth sailing, even with all that genital contact.

"These coalitions can be very nasty for males," he said. Females might collectively mete out discipline indiscriminately and gang up on the guys for no reason, leading to intense attacks and injury.

Block said female bonobos might jump on a male who steps out of line.

"They're not nonviolent," she said. "It's not like they're hippy peaceniks. They punch and bite and hurt each other. They just don't kill each other, and that also shows me how smart they are, because they seem to hold back. [The female bonobos] make sure the males are happy. Very often, if a male attacks a female, the females will beat him up and then give him a blowjob or something, or pet him or give him a hug."

Fornication is frequent and quick—just a few seconds—but the potential for ostensibly arbitrary punishment from an alliance of upset females is ever-present.

"It seems to be a Damocles sword that hangs above these males [with] these female coalitions," Surbeck explained.

Bonoboville as a fount of social-sexual inspiration

Can what Block calls "Bonoboville"—referring to the Pan paniscus consociation and bonobo-inspired community she's cultivated—offer inspiration for humanity as a whole?

Different groups of bonobos display tolerant interactions with each other, according to Surbeck, who's the principal investigator for Harvard's Pan Lab, which brings together primatologists in the study of the behavioral ecology of bonobos and chimps to help understand human behavior. Researchers hope to establish a bonobo model for human evolution, according to the lab's website.

"The bonobos there would just offer us a model to understand what facilitates tolerance between groups, what the circumstances are that have to be changed," Surbeck said.

In addition to the hormone oxytocin, Surbeck's lab has tested for bonobo male testosterone. In other species, the hormone is associated with mating contests and correlated with increased aggression through sexual competition, but bonobos don't experience elevated testosterone in response to those same relations. This suggests aggression doesn't play a crucial role in getting access to females, according to Surbeck. He said the prolonged bonobo ovulation period and the predilection among those females for more or less allowing all males to mate probably works in tandem with the power of female bonobo solidarity to prevent the infanticide seen in other primates.

Bonobos appear to intuitively grasp the importance of sex, baking it into their everyday experience, ensuring virtually all who desire to do so can regularly partake in erotic pleasure, thereby satisfying individual needs while simultaneously bolstering social cohesion. Perhaps it would behoove us as a species to work on building communities committed to ensuring all human beings receive the chance to enjoy what our closest living relatives guarantee each other.

For her part, Graham would like for people who hear about bonobos to appreciate what a lot of queer people, in particular, glean from learning about other species.

"We're not weird. We're not unusual. We exist," she said. "Sexual behavior is diverse across species and across [human relations]. And that's pretty beautiful."

Bonobos appear to intuitively grasp the importance of sex...thereby satisfying individual needs while simultaneously bolstering social cohesion.

De Waal underscored the commonplace practice of bonobo masturbation, especially the female bonobo's propensity for self-stimulation.

"The clitoris is often forgotten in the whole story," he added. "We all focused on the male and the penis and so on. But female bonobos have a very prominent clitoris, which they stimulate quite a bit."

Just as primatology for too long failed to appreciate female genitalia, de Waal acknowledged the human clitoris and female orgasm have historically been neglected and dismissed. He also stressed the vibrant sexuality of female bonobos.

"They have enormous amounts of sex, enough to include every male in the neighborhood and adjacent territories," de Waal writes in his book. "Female bonobos pursue sex so actively and ardently that they almost turn coercive. Of all the primates I know, they are sexually the most forward."

"It would be exhausting in some ways, I would think. But for the bonobos, it's built into their life," de Waal said. "They meet each other, they have a quick sexual contact and then they sit down and groom each other."

People might not want to emulate their culture of near-continuous, curt copulations. Yet, as de Waal pointed out, there's a Puritan obsession leading to excessive control of sexual expression in British-American culture.

"We could loosen up a bit, you know?" he suggested. "Most people are very uptight about these things."