For a long time now, chimpanzees have been getting a bad rap. On the one hand we recognize that DNA-wise they are our closest match in the animal world, but our treatment of them has left a lot to be desired. At one time we had them on the stage as youngsters having a tea party while being dressed up as human kids. We have even worked at teaching them to understand what we’re saying with well known characters like Washo.
More recently we have TV documentaries showing them as non-cuddly, sometimes predatory thug-like characters who could be modeling themselves on Puzo’s Godfather character.
At the same time, we recognize that humans have a strong prosocial or altruistic streak and we give generously (perhaps) to others who have suffered in a natural disaster. We’re less eager if it’s our fellow citizens in terms of regularizing that altruism via our government, especially if we are having our own regular tea parties, but we agree that monkeys, such as macaques, behave with a marked degree of altruism.
The received wisdom is that chimpanzees don’t. A recent paper in the Proceedings of the National Academy of Science by Horner et al from Emory U has at last shed doubt on that notion (1). They indicate that the previous testing methods are probably the reason that great notion was flawed.
The recent study was done with 7 female chimpanzees and they had to choose a token for treats. The choice was between two tokens of different color. One color provided one helping of treats, while the other color provided two helpings so that the other chimp in the room could indulge too.
The chimp girls showed a propensity for going for the two-helping token so they could share with their cell-mate. Interestingly though, if they were bunking with a greedy, whiney cell-mate, they went for the single treat token and had to be pleaded with and pestered to go for double treats.
So maybe, just maybe, that 2% DNA difference is smaller than we thought.
