Human

Humans May Have Evolved Sense of 'Fairness' to Encourage Cooperation (VIDEO)

Catherine Griffin
First Posted: Sep 19, 2014 06:38 AM EDT

Did humans evolve fairness to support cooperation? That may just be the case. Scientists have found that humans may have evolved the concept of "fairness" in order to support partnerships in groups and better their chances at survival.

 "This sense of fairness is the basis of lots of things in human society, from wage discrimination to international politics," said Sarah Brosnan, one of the researchers, in a news release. "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 response to inequality were common in other cooperative species."

Fairness is a social ideal that can't be measured. That's why the researchers turned to primates in order to examine behavioral responses to equal versus unequal reward division. In this case, the researchers gave a superior reward to one capuchin monkey in the presence of another capuchin monkey after they both performed the same task. They found that the one that received the lesser reward became agitated.

Yet responding to getting less than a partner is not the only aspect of fairness. For a true sense of fairness, it matters if you get more; for example, humans will give up a benefit in order to reach equal outcomes and stabilize long-term cooperative relationships. So far, though, this behavior has only been found in humans and apes.

"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," said Brosnan. "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."

The findings are published in the journals Science and Nature.

Want to learn more? Check out the video below, courtesy of YouTube.

See Now: NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone

More on SCIENCEwr