People who take the law into your own hands and engage in costly punishment are doomed to fail, for a new study has found that nice folks do finish first.
Researchers at the Harvard University and the Stockholm School of Economics, discovered that leaders who resort to costly punishment do not benefit from their behaviour.
The group, led by Martin A. Nowak of Harvard's Program for Evolutionary Dynamics, Department of Mathematics, and Department of Organismic and Evolutionary Biology, examined cooperation among subjects playing a modified version of the Prisoner's Dilemma.
This game captures the deep-seated tension between the interests of the individual and the group, and is the classic idea for cooperation.
The researchers showed that the use of punitive behaviour correlates strongly with reduced individual payoff, and bestows no benefit on the group as a whole.
"Put simply, winners don't punish. Punishment can lead to a downward spiral of retaliation, with destructive outcomes for everybody involved. The people with the highest total payoffs do not use costly punishment," Nature quoted co-author David G. Rand of Harvard's Program for Evolutionary Dynamics and Department of Systems Biology, as saying.
"Costly punishment," the type of punitive behaviour studied by Nowak and his colleagues, refers to situations where a punisher is willing to incur a cost in order to penalize someone else.
Other research has suggested that punishment can elicit cooperation in one-time situations where participants aren't worried about damaged reputations or retaliation, the study said. That notion is unrealistic because reputations are "always at stake,'' and most interactions are repeated, Nowak and his colleagues found.
"There's been a lot of previous work on the use of punishment in cooperation games, but the focus has not been on situations where individuals use punishment in the context of ongoing interactions," says co-author Anna Dreber of the Stockholm School of Economics and the Program for Evolutionary Dynamics at Harvard.
Working with the Harvard Business School, Prof Nowak asked 104 college students to take part in a variant of a classic game, called the Prisoner's Dilemma. In this game people have a choice between cooperation and defection. Cooperation means paying 1 dollar for the other person to receive 3 dollars.
Defection means taking away 1 dollar from the other person. In the extended version of the game there is a third option - costly punishment, which means paying 1 dollar for the other person to lose 4 dollars.
The study found that those who punished lost out overall, and that punishment bestows no benefit on the group as a whole.
The five top-ranked players never used costly punishment. More successful players would use tit for tat, while players who earned the lowest payoffs punished most often.
The new study, according the scientists, shows that punishment is not an effective way to promote cooperation, the glue that holds society together, but probably evolved for other reasons such as establishing dominance and defend ownership.
"Punishment may be a tool for forcing another person to do what you want. It might have been for those kinds of dominance situations that the use of punishment has evolved," Dreber said.
"Our finding has a very positive message: in an extremely competitive setting, the winners are those who resist the temptation to escalate conflicts, while the losers punish and perish," added Nowak.
The study is published in the journal Nature.