Monkeys, chimps and other primates go ballistic when they receive unequal pay, much in the way that humans fume under similar circumstances, according to a new study that also helps to explain the reaction.
The angry response to perceived unfairness evolved in order to support long-term cooperation, according to the research, published in the journal Science.
The research explains a popular video that went viral. The video shows what happens when a brown capuchin monkey figures out that he’s being ripped off.
Even Sarah Brosnan of Georgia State’s department of Psychology and Philosophy, who led the new study, still gets a kick out of this classic experiment.
“The video is definitely the best,” she told Discovery News. “The presence of this response across so many species likely indicates that we — and these other species — evolved to respond this way because it was so beneficial in the context of cooperation.”
She continued, “We are certainly not the only species that responds to inequity now, and it seems very likely that our ancestors did as well, especially as we know that they cooperated on a large scale.”
The video was shot in 2003, and since then, Brosnan, colleague Frans de Waal and others have determined that nine primate species, including humans, have an aversion to inequity. They reviewed the research for the latest study, as well as experiments conducted by other teams.
It’s likely that there is a genetic component to the behavior, as well as a learned one. What is clear is that humans aren’t the only ones who sometimes feel slighted, and this can be very emotional.
“We don’t know how other species feel about inequity because we can’t ask them,” Brosnan said. “That being said, it is likely that their responses are underpinned by an emotional reaction to the inequity of a situation, much as ours are. One difference in IA (inequity aversion) in humans as compared to other species is that for us, fairness has become a social ideal, which is unique to humans.”