Chimps selfish when it comes to food
Some things cannot be explained by evolution. Chimps and bonobos don't share an innate sense of fairness with their closest human kin.
Keith Jensen, professor at Queen Mary's School of Biological and Chemical Sciences, was among scientists who put the apes through a series of games.
The games were set up in a variety of different ways, involving equal portions of grapes or unequal ones.
One against the other, they had to choose whether to steal or leave the other's grapes, the journal Biology Letters reports.
Jensen explained: "In each scenario one ape had to choose whether to steal the grapes or leave a portion of grapes for the other. We found that consistently they would steal the food without taking into account whether their action would have an effect on their partner."
"Neither the chimpanzees nor bonobos seemed to care whether food was stolen or not, or whether the outcomes were fair or not, as long as they got something," said Jensen.
"...our results indicate that our sense of fairness is a derived trait and may be unique to the human race," added Jensen.