It looks like humans aren’t the only ones that judge, as researchers have just found that monkeys also evaluate others.
In a recent study, researchers found capuchin monkeys can determine when a human is acting selfish, and if they are, they have a tendency to avoid them.
The study included humans acting selfish and humans acting helpful while the monkeys watched.
Afterward, the monkeys were less likely to accept food from the selfish actors.
“We found the monkeys accepted food less frequently from the human performers who persistently rejected the other person’s request for help. This research is significant as it provides evidence that social evaluation based on third-party interactions - the way we respond to others - is not unique to humans,” Dr. Jim Anderson said.
They are publishing their findings in online journal Nature Communications this week.
At an early age, human beings start evaluating each other by eavesdropping or hearing about their reputations.
But there has been, until now, little research on the development of social evaluations in other species.
“The situations acted out in front of the monkeys were of no direct relevance to the animals. However, they judged the interactions of the humans and their disposition,” Anderson said.
“This research complements another paper, recently published in journal ‘Cognition,’ showing that capuchin monkeys also negatively evaluated humans who refused to fully reciprocate in an exchange of objects with another person.”
“In other words, the monkeys tended to avoid people who behaved selfishly in interactions with others.”
“Humans routinely socially evaluate others not only following direct interactions with them but also based on others’ interactions with third parties. Evaluation of potential helpfulness based on third-party interactions may thus not be unique to humans.”
Capuchin monkeys are known for being highly intelligent. In recent years, they have been trained as aides for the paraplegic, and some people also own them as pets.