Development of human societies requires cooperation among unrelated individuals and obedience to social norms. Although punishment is widely agreed to be potentially useful in fostering cooperation, many recent results in psychology and economics highlight punishments' failures in this regard....

Convergent evidence for detrimental effects of punishment on cooperation has been obtained in a wide variety of environments, ranging from American students facing punishment in laboratory experiments, to Israeli parents facing fines for arriving late to their child’s day care. We show here...

People can become less cooperative when threatened with sanctions, and researchers have pointed to both 'intentions' and incentives as sources of this effect. This paper reports data from a novel experimental design aimed at determining the relative importance of intentions and incentives in...

People can become less cooperative when threatened with sanctions, and researchers have pointed to both 'intentions' and incentives as sources of this effect. This paper reports data from a novel experimental design aimed at determining the relative importance of intentions and incentives in...

Development of human societies requires cooperation among unrelated individuals and obedience to social norms. Although punishment is widely agreed to be potentially useful in fostering cooperation, many recent results in psychology and economics highlight punishments' failures in this regard....

Evolutionary theory reveals that punishment is effective in promoting cooperation and maintaining social norms. Although it is accepted that emotions are connected to punishment decisions, there remains substantial debate over why humans use costly punishment. Here we show experimentally that...

This paper investigates how punishment promotes cooperation when the punishment enforcer is independent of its proposer. In a prisoner's dilemma experiment, compared with the case when the implicated parties are allowed to punish each other, cooperation is lower when the enforcement of...

The need for justification is a widely observed social phenomenon. This paper develops a theoretical framework and reports laboratory evidence to show how pure justification pressure affects cooperative behavior in economic exchange environments. In a one-shot anonymous interaction, compared...

This paper investigates how punishment promotes cooperation when the punishment enforcer is a third party independent of the implicated parties who propose the punishment. In a prisoner's dilemma experiment, we find an independent third party vetoes not only punishment to the cooperators but...