No Fair! Primate Studies Probe Why We Hate Inequity
Think of a time when you were treated unfairly. Really cast your mind back to that time and how you felt. Maybe your teeth clenched. Maybe your cheeks burned. Makes you mad just thinking about it, doesn’t it?
Recently published research suggests that the strong objection we have to being treated unequally is very deeply seated in our evolution. Researchers found that an objection to getting less is an evolutionary response that protects members of cooperative species from others of their kind doing better at their expense.
Dr. Sarah Brosnan of Georgia State’s departments of Psychology and Philosophy, the Neuroscience Institute and the Language Research Center and colleague Dr. Frans de Waal of the Yerkes National Primate Research Center and the Psychology Department at Emory University published their first study of primate reaction to being treated unfairly, “Monkeys Reject Unequal Pay” in 2003, in which they found that capuchin monkeys have a freakout if they see other monkeys get a bigger reward for the same task.
Over the next 10 years the pair continued to study inequity responses in nine different primate species, finding that only routinely cooperative species, like humans, have a negative reaction to unequal treatment. They recently published a new paper on their long-term results.
“This sense of fairness is the basis of lots of things in human society, from wage discrimination to international politics,” Brosnan said. “What we’re interested in is why humans aren’t happy with what we have, even if it’s good enough, if someone else has more. What we hypothesize is that this matters because evolution is relative. If you are cooperating with someone who takes more of the benefits accrued, they will do better than you, at your expense. Therefore, we began to explore whether responses to inequity were common in other cooperative species.”
Of course, there’s a big gulf between recognizing that something is unfair to you, and that recognizing something you’re doing is unfair to others. Only humans and apes are evolved to be able to see this, the study found.
“Giving up an outcome that benefits you in order to gain long-term benefits from the relationship requires not only an ability to think about the future, but also the self-control to turn down a reward,” Brosnan said. “These both require a lot of cognitive control. Therefore, we hypothesize that lots of species respond negatively to getting less than a partner, which is the first step in the evolution of fairness, but only a few species are able to make the leap to this second step, which leads to a true sense of fairness.”
[Source: Georgia State University]