How is this for provocative… the location of the human clitoris may be explained by lesbian sex in bonobos, a smaller form of chimpanzees and the animal species genetically closest to humans.

Bonobos are fully bisexual in a matriarchal society, and about half of their sex is same-sex. Also, they have a lot of sex, averaging once every two hours, and twice that often if the relationship is new. Female bonobos are particularly sexual with each other. One female will wrap her arms and legs around another, face to face, staring into each others eyes as they rub their genitals together, screaming and grimacing until they climax. Females also have sex by rubbing their butts together or mounting the other from behind. Males have many ways to interact as well including fondling each other, performing oral sex, and engaging in the descriptively named “penis fencing” which lead to ejaculation.

Interestingly, numerous studies show that bonobos maintain a peaceful society by using sex as an alternative to conflict in their social relations. When researchers put a new and intriguing object into a cage with two female bonobos, they will often have sex with each other before they approach the gift, presumably for stress release.

Meanwhile, in humans, one of the puzzles of human physiology is why the female’s main sensory spot is located separately from the place of direct sexual contact. In males the pleasure center is at the end of the penis, which is why men can happily stick it into just about anything. This motivates men to have sex with women–he derives pleasure from putting his cock into a vagina. But the female is not similarly wired for direct pleasure in intercourse. The orgasmic functions are particularly complex, largely because of the clitoris’s location. But why?

One answer is that the male is already motivated for sex and the resulting procreation, leaving the female body free to evolve for other purposes. The famous primatologist Frans de Waal wrote in 1995, “The frontal orientation of the bonobo vulva and clitoris strongly suggest that the female genitalia be adapted for this [frontal] position.” In her book Evolution’s Rainbow, Stanford biologist Joan Roughgarden notes that,

From the standpoint of female reproduction, little is gained by placing the clitoral neurons near the vagina to further same-sex mating when males are well motivated for intercourse anyway. Instead, the pleasure neurons are shifted to a location that promotes same-sex mating and may yield more effective same-sex bonds, increasing overall Darwinian fitness at no reproductive cost.

Roughgarden also notes that Bonobos are one of the few mammals that have heterosexual sex face-to-face. So from the location of the Bonobo female clitoris, we derive that Bonobos evolved bodies that promote same-sex bonding resulting in face-to-face heterosexual sex.

The mind reels. Could it be that human females evolved a frontal clitoral pleasure center because female-female sexual bonding was so vital to our development? Do human males favor the missionary position because of the ways lesbian bonding affected female bodies? And most importantly to men who want to please their partners, is the clitoris separated from the vagina for reasons that have nothing to do with men? This explains a lot of male frustration in chasing elusive female orgasms, as men are fighting a battle nature rigged for the other team. We can conclude that if men get pleasure wherever they put their penis, and women are designed to find pleasure each other, we end up with a same-sex twist on a classical formulation: men sow their seed, and women bond…with each other.

Overwhelming as it seems, every human female body may be a testament to the power and importance of same-sex bonding in women.