Cari Romm writes: In a lot of ways, we have more in common with chimpanzees than we do with bonobos. Both species of ape are considered humans’ genetically closest living relatives, but chimpanzees live in patriarchal societies, start wars with their neighbors, and, as a paper published today in Proceedings of the National Academy of Sciences put it, “do not take kindly to strangers.”

By contrast, bonobos, which form female-dominated societies, have no problem welcoming outsiders into the fold: They mate, share food, and readily form bonds with strangers. They’re also great at defusing conflicts before they escalate — when bonobos stumble upon a new feeding ground, for example, they tend to celebrate with group sex before eating, a habit researchers believe is meant to relieve tension that could otherwise translate into competition for food.

We do share some things with the warmer, fuzzier contingent of our ape family tree: In 2013, for example, researchers from Emory University found strong similarities between the emotional development of young bonobos to that of human children. But in the recent PNAS paper, a team of researchers from the Netherlands found one more difference: Where humans are primed to pay more attention to threats, bonobos are more captivated by examples of cooperation. [Continue reading…]