New research challenges the notion that punishment is motivated by revenge.
Instead, researchers from University College London and Harvard University say we punish cheats only when they end up better off than us.
Published in the journal Biology Letters, the research shows that victims of cheating compare their own payoffs with those of partners when making decisions about punishment.
“Punishment is a costly behavior which is often aimed at individuals that cheat during social interactions,” said Dr. Nichola Raihani, from University College London and lead author of the study.
“Imagine a thief steals $10 from you. Would you punish him because he cost you $10, or would you only punish if the thief ended up $10 richer than you?”
Although punishers make an initial investment to harm cheats, the investment may be repaid if the cheat behaves more cooperatively in the future, she noted.
To find out more about the underlying motivations of human punishment, the research team devised an experiment to see whether it is triggered by a desire to reciprocate losses or by an aversion to unequal outcomes.
Subjects were assigned one of two roles, and then allocated money according to one of three different treatments.
The team found that humans are sensitive to inequity but not to losses when deciding whether to punish a cheating partner.
“Several previous studies have shown that punishment is motivated by negative emotions. However we wanted to know what precisely makes people want to punish cheats,” said Raihani. “Is punishment motivated purely by a desire for revenge, or do individuals judge whether cheats end up better off than them before deciding whether to punish?”
Clarifying the motives that trigger punishment may yield insights into the ultimate function of punitive behavior in humans, the researchers said, noting it may be that punishment is aimed at promoting fair behavior rather than simply deterring people from cheating.
Such insights may tell us where punishment is most likely to be implemented and where it is most likely to be effective, the researchers conclude.
Source: University College London