Press release: Arguing for cohesion: Study traces the course of vendettas

Nr. 169/2012 - 21.09.2012

Göttingen researchers investigate mechanisms of punishment and retribution

(pug) Long-lasting vendettas among neighbours or families generally follow similar patterns: along the bibli-cal lines of ‘an eye for an eye, a tooth for a tooth’, the quarrelling parties try to hurt one another to get their own back for perceived wrong. In this process, what it was that originally triggered the dispute is often forgotten. Researchers at the University of Göttingen and the Max Planck Institute for Evolutionary Biology in Plön have now delivered experimental evidence of this behaviour. Participants in the study had the possibility of punishing their co-players in a game of cooperation. If the latter considered themselves to have been treated unfairly, they got their revenge at the next opportunity with ‘retaliatory punishment’. These results have appeared in the journal PLOS ONE.

Cohesion and cooperation are necessary if a community is to function. In evolutionary biology, the possibility of punishing members of a community is regarded as an important mechanism for supporting cooperative behaviour. But if the punished party takes revenge, the real purpose of the punishment is lost. In this case, the mechanism is disadvantageous to the community because it is associated with expenditure of effort on the part of all those involved. If there follows a chain of reciprocal punishments this is referred to as a feud or vendetta – a well-known example in literature is the long-standing dispute between the families Montague and Capulet in William Shakespeare’s Romeo and Juliet. Up to now, however, scientific investigations have focussed primarily on the consequences of a single act of punishment and less on the consequences of multiple punishments and counter-punishments.

In the study carried out by the Göttingen behavioural biologists, the approximately 140 participants had a set budget at their disposal. The money remaining at the end of the study was paid out to the participants in cash. If they wished to punish another participant, they were required to pay a certain sum while at the same time the punished party had to pay a higher amount. The act of punishing therefore constituted a burden to all participants and led to them suffering a financial setback, above all in comparison with those participants who chose not to punish. Nevertheless, the researchers were able to demonstrate that even under experi-mental conditions, people let themselves in for punishment vendettas. “If the punished participant felt unfairly treated, he got his own back with an equally high punishment in the next round of the game, even though the disadvantages were known to him”, explains the study’s director Dr. Katrin Fehl of the Courant Research Centre ‘Evolution of Social Behaviour’ at the University of Göttingen.

In the course of the study, some participants also developed a strategy for retribution that avoided the risk of a longer-term feud: although they could only guess at the planned number of rounds to be played, they postponed their revenge for as long as possible so that the ending of the game would prevent any possible further retaliation. What is more, the group of participants resolving independently to bring a feud to an end during the game consisted, surprisingly, to an equal extent of players who had previously acted coopera-tively and uncooperatively. “This shows that under certain circumstances, even destructive vendetta punish-ment can have positive effects on cooperation within a community”, says Dr. Fehl.

Original publication: Katrin Fehl et al. I Dare You to Punish Me – Vendettas in Games of Cooperation. PLOS ONE 2012. Doi: http://dx.plos.org/10.1371/journal.pone.0045093.

Note to editors:
Images on this topic have been made available for download at www.uni-goettingen.de.

Contact address:
Dr. Katrin Fehl
Georg-August-Universität Göttingen
Courant Research Centre Evolution of Social Behaviour
Kellnerweg 6, 37077 Göttingen, Germany
Tel.: +49 (0)551 39-14682
Email: katrin.fehl@bio.uni-goettingen.de
Internet: www.uni-goettingen.de/de/265268.html