Consistency-based rewards could build lasting cooperation better than punishing free-riders

Cooperative behavior thrives in societies when members consistently contribute to shared goals, much like vaccines become effective only when a sufficient proportion of the population is immunized. However, individuals often have an incentive to avoid contributing themselves, a phenomenon known as free-riding. A new study published in the Proceedings of the National Academy of Sciences explores how consistent cooperation can be sustained through rewards, as opposed to punishing those who do not cooperate.

Mathematical models developed by Feng Fu, a professor of mathematics at Dartmouth, and his graduate student Alina Glaubitz, revealed that rewarding consistently cooperative players leads to the formation of two distinct groups: those who always cooperate and those who never do. This split was more pronounced under an all-or-nothing reward structure, where steady cooperators receive the largest rewards while anyone who fails to cooperate at any point receives nothing.

The size of the reward itself also played a role, with larger rewards encouraging more individuals to consistently cooperate.

In contrast, punishment did not produce the same effect, regardless of how it was implemented. This suggests that incorporating rewards contingent on consistent cooperation could be an effective strategy for fostering cooperation in various social structures, such as climate action or social movements. However, the authors caution that determining the value of cooperation and the cost of providing rewards or enforcing punishments is crucial in order to assess the practical viability of such strategies.