Often mistaken for chimpanzees, bonobos are slightly smaller, with longer black hair atop their heads and pink lips. Unlike male-dominated chimp culture, it's the female bonobos that rule their communities. In these matriarchal societies, alliances are strong and females gang up together on males who step out of line.
There is another difference: while bonobos live in relatively peaceful communities, chimpanzees sometimes engage in a kind of primitive warfare. These instances were famously first documented the 1970's between two neighboring groups at Gombe by primatologist Jane Goodall. Gangs of roving chimps beat, tortured, and killed their rivals to acquire new territory. Since then, other scientists in the field have recorded equally horrible and gruesome accounts of conflict. Sometimes there is even infanticide and cannibalism.
Though bonobos can get feisty at times, on the whole their culture is markedly different. When conflicts arise, tensions are more often eased through sex than aggression. It may sound like a kind of hippie-utopia, but there's more going on than free love. And this is the reason that scientists are keenly interested in learning more about this unusual ape.
In their controlled experiments, Hare and Woods have noted marked differences in the way chimpanzees and bonobos react to strangers of their own species. A chimp treats the other as an outsider or rival. If food is available, he will hoard it for himself. However, under the same circumstances at Lola ya Bonobo Sanctuary in the Democratic Republic of Congo, a bonobo will treat the stranger as if he is already part of the same group. If his new companion is locked out of his enclosure containing food, the bonobo finds a way to open the door in order to share his meal. And in case you're wondering, there might be some sex involved between them as well.
So what do such experiments and accounts of war and peace among other primates have to do with our own species? A look back at human history demonstrates that we are unquestionably capable of acting at both ends of the spectrum. Sometimes we do absolutely terrible, evil things to each other. We commit murder and genocide in the name of race, religion and prejudice of all sorts. We engage in war over boundary and resource disputes. In other words, there is an aggressive side to humanity that is often also visible in chimpanzee populations.
Yet we also clearly have the capacity to do a tremendous amount of good. We provide food and medicine to strangers in need through international aid organizations. We donate organs to unknown recipients. We sponsor children in the developing world so that they can go to school. These generous traits are reflected, to some degree, in the less aggressive bonobos.
By understanding all we can about the behavior and biochemistry of both species, evolutionary biologists such as Hare and Woods suspect that we may learn more about what pushes humans toward either extreme. And if we're lucky, that knowledge could be the key to a more peaceful existence for all of us.
Guest blogger Sheril Kirshenbaum writes frequently on the relationship between science and culture. She is also director of The Energy Poll at The University of Texas at Austin. You can keep up with what she's thinking on Twitter and on the Web.