Sanctions are used ubiquitously to enforce obedience to social norms. Recent field studies and laboratory experiments have demonstrated, however, that cooperation is sometimes reduced when incentives meant to promote pro-social decisions are added to the environment. Although a variety of...

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...

The millions of deaths that occurred during China's great famine of 1959-1961 were the result of one of the world's greatest civil demographic disasters. Two primary hypotheses have been advanced to explain the famine. One is that China experienced three consecutive years of bad weather while...

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...

Research in economics and psychology has established that informal non-monetary sanctions, particularly expressions of negative emotion or disapproval, can enforce fair economic exchange. Scholars, however, are only beginning to understand the reasons non-monetary sanctions affect economic...

Inequality aversion is a key motive for punishment, with many prominent studies suggesting people use punishment to reduce or eliminate inequality. Punishment in laboratory games, however, is nearly always designed to promote equality (e.g., rejections in standard ultimatum games) and the...

People can become less cooperative when threatened with sanctions, and previous research suggests both "intentions" and incentives underlie this effect. We report data from an experiment aimed at determining the relative importance of intentions and incentives in producing non-cooperative...

We report data from public goods games showing that privately-implemented punishment reduces cooperation in relation to a baseline treatment without punishment. When that same incentive is implemented publicly, however, cooperation is sustained at significantly higher rates than in either the...

We report data from a laboratory experiment using dictator games to inform individual preferences over punishment outcomes. We find that many people punish after receiving disadvantageous outcomes, and those who do systematically prefer to use punishment to create self-advantageous inequality.