Monkeys avoid selfish others: study

Researchers investigated how capuchin monkeys in captivity reacted to different third-party social interactions.

In one study, capuchins watched two actors engage in reciprocity exchanges, in which one actor handed over several balls to another, who then either reciprocated or selfishly kept all the balls.

The second study involved a similar setup, but this time one actor helped or refused to help another actor who was struggling to open a container, LiveScience reported.

After each scene, the monkeys chose a treat from one of the actors - they consistently avoided treats from actors who refused to reciprocate or help.

Capuchins in the wild may keep tabs on group members to figure out whom to avoid interacting with on a specific day, researchers said.

James Anderson, a primatologist at the University of Stirling in Scotland and lead author of the new studies tested capuchins' reactions to scenes of reciprocity.

Two actors began with two containers each, one of which contained three balls. One actor held out an empty container to the second actor, who then placed her balls into the container.

Next, the second actor similarly requested balls from the first actor. In half of the trials, the first actor refused to reciprocate and kept all six balls to herself.

The primates showed no preference when both actors reciprocated, but they consistently avoided taking treats from non-reciprocators, the researchers found in the study, detailed in the journal Cognition.

In a companion study, published

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