WikiFindings

The ‘cooperative phenotype’: people that pay a cost to themselves to help a stranger, are likely to do so again and in different circumstances.

Background

We are extraordinarily cooperative, and understanding when and why we cooperate is fundamental to glimpse into what made us such a successful species. Researchers use game theory to study preferences that arise when contrasting personal and cooperative interests are at play. Commonly used games are, for example: the ‘dictator game’ - in which one player is given a sum of money and is asked to choose if and how much to share with the second player; or the ‘ultimatum game’ - similar to the dictator game, but player two can decide to forego the donation, if considered too small. The latter is an example of an economic game with a ‘punishment’ option. Studies using game theory rely on the assumption that behaviour in economic games is representative of behaviours in other contexts. Nevertheless, this assumption remains widely untested, as does the reliability of economic games as useful models of real-world cooperation.

Findings

This study compares results in six economic games (three with a punishment option), self-report measures of pro-sociality values and behaviours, and actual behavior in real-world settings. The idea is that we can talk of a ‘cooperative phenotype’ if individual’s choices in different cooperative contexts are correlated. Results show that players consistently choose to cooperate in the cooperative economic games, and that choices in these games are correlated with measures of pro-sociality values, as well as with behaviours in the real world. Instead, the correlation does not extend to the games with a punishment component, suggesting that the ‘cooperative phenotype’ does not cover these behaviours. Finally, all these results were replicated after several months, showing stability of choices over time.

Implications

Therefore, we can use a psychologically relevant definition of cooperative personalities – personalities characterized by individuals that are willing to pay a cost to help others. In fact, there is a strong correlation between cooperative behaviours among different contexts and in time, giving great support to the ‘cooperative phenotype’ idea, and showing that economic games are a reliable tool to study cooperation. The lack of correlation between cooperation and punishment games also highlights that punishment may not be driven by cooperative purposes. This is an important finding, as many models of evolutionary theory have assumed that cooperation and punishment are linked. These modes should be updated in the light of this new information.