For the study, researchers Victoria Horner and Frans de Waal conducted a test that focused on offering seven adult female chimpanzees a choice between two similar actions: one that rewarded both the participant and a partner, and another that rewarded only the participant . In each trial, the subject who chose, always with a partner in sight, chose between different colored cards. One token could be exchanged for food offered to both members (prosocial), and another token of another color offered food only to the one who chose (selfish). All seven chimpanzees showed a preference for the prosocial option .
The study also shows that the subjects were altruistic especially with those who waited patiently and carefully reminded them that they were there. Chimpanzees who chose the tokens were less likely to reward those who made a fuss, begged, or spat water on them, thus showing that their altruism is spontaneous and not subject to intimidation .
Now, the researchers plan to determine whether the altruistic tendency of chimpanzees is related to social interactions within the group, such as the exchange of food or social support.
