It’s a question that has puzzled thinkers for centuries: Are we humans alone in our pursuit of fairness and the frustration we feel when others get what we want?
In recent years, evolutionary psychologists have suggested that we’re not all that special. Animals, from corvids to capuchin monkeys, express what humans might recognize as jealousy when, for example, they are passed over for a sought-after snack. Many argue this is evidence we are not alone in our aversion toward unfairness.
But new research from the University of California, Berkeley, makes the case that humans might be unique after all.
Using data from 23 studies of what psychologists call “inequity aversion,” Berkeley researchers combed through results of more than 60,000 observations involving 18 animal species. In what they said was the “largest empirical investigation of non-human inequity aversion to date,” the team reconstructed data analyses and used a new metric that adds depth to the concept of fairness.
“We can’t make the claim that animals experience jealousy based on this data,” said Oded Ritov, a fourth-year Ph.D. candidate in UC Berkeley’s Department of Psychology. “If there is an effect, it’s very weak and might show up in very specific settings.