Punishment does not earn rewards or cooperation, study finds

Individuals who engage in costly punishment do not benefit from their behavior, according to a new study published this week in the journal Nature by researchers at Harvard University and the Stockholm School of Economics.

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 fundamental tension between the interests of the individual and the group, and is the classic paradigm for cooperation. The study found that the use of punitive behavior correlates strongly with reduced individual payoff, and bestows no benefit on the group as a whole.

"Put simply, winners don’t punish," says co-author David G. Rand of Harvard's Program for Evolutionary Dynamics and Department of Systems Biology. "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."

"Costly punishment," the type of punitive behavior 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 researchers have suggested that costly punishment can compel cooperation in one-time interactions where individuals need not worry about reputation or retaliation -- a scenario Nowak and his colleagues found unrealistic, since, as they write, "most of our interactions are repeated and reputation is always at stake."

"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. "We make the setting more realistic by having subjects play repeated games and introducing costly punishment as one of several options."

Dreber, Rand, Nowak, and Drew Fudenberg of Harvard's Department of Economics recruited 104 Boston-area college students to participate in a computer-based Prisoner's Dilemma game that was extended to include costly punishment alongside the usual options of cooperation and defection. Pairs of students played the game repeatedly so the interaction between costly punishment and reciprocity could be assessed.

The result: There is a strong negative correlation between individual payoff and the use of costly punishment. The five top-ranked players never used costly punishment, while players who earned the lowest payoffs tended to punish most often. Winners used a tit-for-tat like strategy while losers used costly punishment. Furthermore, costly punishment did not increase the average payoff of the group.

The study shows that punishment is not an effective force for promoting cooperation. The unfortunate tendency of humans to engage in acts of costly punishment must have evolved for other reasons such as establishing dominance hierarchy and defending ownership, but not to promote cooperation. In cooperation games, costly punishment is a detrimental and self-destructive behavior.

"Punishment may be a tool for forcing another person to do what you want," Dreber says. "It might have been for those kinds of dominance situations that the use of punishment has evolved."

"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," concludes Nowak.

Source: Harvard University

Related stories:

Cooperation, punishment and revenge
Research from The University of Nottingham has shed new light on the way in which people co-operate for the common good — and what happens when they don’t.
Brain's 'social enforcer' centers identified
Researchers have identified brain structures that process the threat of punishment for violating social norms. They said that their findings suggest a neural basis for treating children, adolescents, and even immature adults differently in the criminal justice system, since the neural circuitry for processing the threat of such punishment is not as developed in younger individuals as it is in adults. The researchers also said that their identification of the brain’s “social norm compliance” structures also opens the way to exploring whether psychopaths have deficiencies in these structures’ circuitry.
ACT Warns of Legal Risk with Latest GPL Draft
Patent-related proposed amendments to the license could possibly do more harm than good by "selectively overreaching" for third-party patent rights, an ACT lawyer says.
When reputation matters, punishment may be reduced to the extreme cases
Scientists at the Max Planck Institute of Limnology and the University of Erfurt have discovered that even in the presence of effective reputation mechanisms, people do not entirely cease punishing those that put self-interest ahead of the collective interest. When given a choice, subjects even prefer a society with the option of both maintaining their own reputation and punishing "free riders". Acts of punishment are rare but imposed in a targeted manner.
Punishment linked to profits, says study
Punishment may not be all that bad when it comes to making profits, says a German study.
In spite of ourselves
Humans have a strong desire to help each other, but is spite also part of the human condition?
In a study published in the Proceedings of the Royal Academy, Keith Jensen and colleagues from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany looks at altruism and spite in our close cousin; the chimpanzee.
New approach needed to help street-based sex workers
Integrated multi-agency work will be needed to address the poor physical and mental health experienced by street-based sex workers (SSWs), according to recent research including a new study by .
Study examines the psychology behind students who don't cheat
While many studies have examined cheating among college students, new research looks at the issue from a different perspective – identifying students who are least likely to cheat.

News discussion:

Medicine & Health news