DURHAM, N.C. Sharing is a behavior on which day care workers and kindergarten teachers tend to offer young humans a lot of coaching. But for our ape cousins the bonobos, sharing just comes naturally.
In fact, according to a pair of papers in the latest Current Biology, it looks like bonobos never seem to learn how not to share. Chimpanzees, by contrast, are notorious for hogging food to themselves, by physical aggression if necessary. While chimps will share as youngsters, they grow out of it.
In several experiments to measure food-sharing and social inhibition among chimps and bonobos living in African sanctuaries, researchers from Duke and Harvard say these behavioral differences may be rooted in developmental patterns that portray something about the historical lifestyles of these two closely related apes.
When compared with chimps, bonobos seem to be living in "a sort of Peter Pan world," said Brian Hare, an assistant professor of evolutionary anthropology at Duke University, who participated in both studies. "They never grow up, and they share."
Hare and his mentor, Richard Wrangham, the Ruth Moore Professor of Anthropology at Harvard, think this kinder, gentler ape's behavior has been shaped by the relative abundance of their environment. Living south of the Congo River, where food is more plentiful, bonobos don't compete with gorillas for food as chimps have to, and they don't have to compete much with each other either.
In essence, they don't have to grow up, Hare said, and cognitive tests that the team performed on the captive animals seem to bear that out. Bonobos shared like juveniles even after they reached adulthood.
"It seems like some of these adult differences might actually derive from developmental differences," said Harvard graduate student Victoria Wobber, who is the lead author on one of the papers. "Evolution has been acting on the development of their cognition."
|Contact: Karl Leif Bates|