When reputation matters, you can benefit by cooperating

November 2010

Why do people give to charity or make other contributions to the public good? What are the advantages to individuals in performing charitable acts with no direct benefit to themselves or their kin?  These questions are still debated in the fields of behavioural science and evolutionary psychology. Dr Gilbert Roberts and Karolina Sylwester at the Institute of Neuroscience have addressed these questions using controlled game playing. They investigated the hypothesis that a person who cooperates with others – even without immediate benefit -- may benefit in the future by developing a reputation that makes him more likely to be chosen for a profitable cooperative partnership. This process is called competitive altruism or reputation-based partner choice.
 
Sylwester and Roberts, who report their results in Biology Letters, recruited individuals to take part in public goods games in groups of four. In these games, participants are given an amount of money and can decide whether to donate some of it to a central pot. Any contributions are doubled and split between the players. Although cooperation would benefit all, it is difficult to achieve because free-riding on others’ contributions pays even better. However, Sylwester and Roberts told participants that they would find out what the other players had donated to the central pot and would then be able to choose partners for a second cooperative game played in pairs.
 
The researchers found that those who gave more in the first stage were more often selected as desired partners and received more from those partners in the paired cooperative game. In this way, those who gave away most money in the early rounds actually finished with more money at the end. It appears that investing in a good reputation by helping others can be a strategic decision which pays off in the longer term. The research suggests that access to profitable partnerships may drive helping behaviour through the benefits of being seen to be cooperative.

Cooperators benefit through reputation-based partner choice in economic games. Sylwester K, Roberts G. Biology Letters 2010, 6(5), 659-662. (PubMed abstract: http://www.ncbi.nlm.nih.gov/pubmed/20410026)

published on: 17th November 2010