Bonobo

Some researchers have suggested that one difference between humans and chimpanzees is that only humans voluntarily share their food with others. Hare and Kwetuenda (2010) experimentally investigated voluntary food sharing in unrelated Bonobos. In their experiments one individual (the "subject") was given the choice of either monopolizing food or actively sharing it with another individual (the "recipient") by releasing the other individual from an adjoining room. This experimental design eliminated relatedness and harassment as motivating factors for sharing. The researchers found that subjects showed a significant preference to open the potential recipient’s door rather than another door to an empty room. Subjects released recipients to co-feed for the majority of the total feeding time during each trial. Compared to control trials in which subjects were presented with one empty room and another room with additional food but no other Bonobo, subjects opened the door to a room with a potential food recipient more quickly than they opened the door to a room with additional food. In a limited set of additional control trials, two test subjects more often released a recipient into a room with food rather than into an empty room, suggesting the possibility of striking altruism. Results from this set of experiments suggest that our own species’ propensity for voluntary food sharing may not be unique among the apes. (Hare and Kwetuenda 2010)