I’ll be honest, I don’t think all of us have moved past our middle school days when any mention of sexuality in a professional (classroom) setting ignited an upsurge of snickers and giggles. Well, hold your laughter, because the bonobo’s wouldn’t see what’s so funny. The Bonobo, or Pan paniscus, is one of our two closest relatives. Many people don’t know that we are just as phylogenetically close to the bonobo as we are to the chimpanzee (and both are closer in relation to each other than to humans). New information regarding the bonobo – specifically their social and sexual behavior – has emerged recently which forces us to look at human behavior and human evolution in a new light.
Bonobos have a very curious and unique mechanism to navigate social organizations and dominance relationships. In their article The Other “Closest Living Relative,” Parish and de Waal investigate how sexual behavior helps to reinforce bonobo social structure. Observations have shown that dominance in bonobo populations, as compared to chimpanzee populations, is much more vague and less defined. It appears as though there is a certain degree of female dominance over males, or as some like to define it “strategic male deference” (Parish and de Waal, 99). Females are in control of their social and reproduction in bonobo societies, and participate in more female – female association than the chimpanzees. Females will often engage in sexual encounters, specifically genital to genital rubbing, for a variety of reasons regarding this unique social structure.
Sexual encounters between females helps to maintain strong alliances between one another and reinforce dominance in a non-violent manner, which thus helps keep tabs, so to speak, on male behavior (Strier, 188). This practice of genital rubbing has a variety of other functions, such as facilitating female immigration into new communities, mediating competition for food, and the reconciliation after occasional acts of aggression. Strier does make a note that aggressive acts between bonobos is actually quite rare, considering the rate of violence in chimpanzees. Bonobos, in contrast to other species, specifically the chimpanzee, engage in all sorts of sexual behavior, not just heterosexual. There were many explicit photos of such processes, which I decided to spare you. So instead, here is a picture of a cute baby bonobo:
Investigation into other forms of social and sexual organization reveal many possible areas of contrast and comparison. There is much less competition between bonobos than with chimpanzees, especially in males. I wasn’t quite sure, from what I could glean from the article, whether this competition was strictly sexual or related to food selection as well. I did think it was interesting that testes size of bonobos was comparable to bonobos; we generally see increased testes sizes in populations with high sexual competition. Bonobos are also highly social compared to other forms of social organizations. Female bonobos while not in estrus remain highly social while female chimpanzees tend to isolate themselves to other females and clinging infants. Chimpanzees, according to Parish and de Waal, are evidently much more likely to avoid one another than encounter each other.
The conclusions that can be made from observing bonobo behavior regarding possible female dominance or “strategic male deference” have massive implications regarding bonobo / chimpanzee / human evolution. As I already mentioned, chimps and bonobos share a last common ancestor with each other, and they both share a last common ancestor with humans. That being said, we can expect that bonobo behavior would be just as good of a predictor of human behavior as chimpanzee behavior. Hominid evolution, according to Parish and de Waal, has been dominated by the idea that humans evolved from creatures like Savannah baboons, and was driven forward by male competition and dominance. Closer inspection of bonobo behavior strongly challenges this notion, and forces us to reconsider the behavior that lead us to become our beloved Homo sapiens. One of my favorite parts of the article, as I tend to consider myself a mild feminist, was the list of themes of sexual and social behavior that we must apply to our understanding of human evolution. That list included but is not limited to: female bonds, possible female dominance, female mating strategies, sharing of vegetation for food, flexible social patterns, and non-violent males (Parish and de Waal, 99).
These very same themes that I have just mentioned above must now be applied to how we study human sexual behavior. We have come to live in a society that seems to – for some reason – value male dominance, especially in sexual and economic relationships. In looking at the bonobos, it seems to stand that our typical male ancestor might not have been inherently violent and dominant. I particularly enjoyed the idea that female oriented and female respecting societies are not as far away as the lemurs, but are much closer than we initially expected.
Rock on female bonobos.