Positive Interactions Promote Cooperation

stick+and+carrotMartin Nowak is quite excited about his new paper in this week’s Science. He writes to us:

I think it has a simple and very interesting result: Reward is better than punishment in promoting public cooperation. (Surprisingly, this finding goes against the current dogma in the field.)

In this case, Nowak and his team had groups of volunteers play a public goods game in which players could decide how much money they wanted to contribute to a common pot and how much they wanted to keep for themselves (the pot would then be divided evenly among the players). Obviously, it’s best for the group if everyone donates the maximum, since it means more money for everyone, but self-interest tells us to donate nothing and freeload off the group. So the researchers added a catch to the classic problem: In some games, players could reward or punish another player for his contribution or lack thereof.
After many rounds of the game, it turns out reward and punishment are equally good at promoting cooperation within the group. But groups in which people could reward each other ended up wealthier than the groups in which people used punishment. When both options are available, rewarding other players leads to greater contributions and payoff, while punishment has no effect on contributions and leads to lower payoff.
As the researchers then note in their paper:

Sometimes it is argued that it is easier to punish people than to reward them. We think this is not the case. Life is full of opportunities for mutually beneficial trade, as well as situations where we can help others, be they friends, neighbors, office mates, or strangers. We regularly spend time and effort, as well as money, to assist people around us. This assistance can be minor, like helping a friend to move furniture, working extra shifts to cover for an ill co-worker, or giving directions to a tourist. It can also be more important, like recommending a colleague for promotion or speaking out to support a victim of discrimination. These sorts of productive interactions are the building blocks of our society and should not be disregarded.

Category: Cooperation


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