Moral sentiments and cooperation: Differential influences of shame and guilt

For centuries economists and psychologists (Frank, 1988; Ketelaar, 2004; Smith, 1759) have argued that moral emotions motivate cooperation. Ketelaar and Au (2003) recently found first evidence that guilt increases cooperation for proselfs in social bargaining games. We investigated whether this effect would also occur for shame, another moral emotion. Using a dyadic social dilemma game in Experiment 1 and an everyday cooperation measure in Experiment 2 as measures for short-term cooperation, we replicated Ketelaar and Au's findings for guilt. However, as predicted on the basis of previous emotion research, we found no such effect for shame. These results clearly indicate that the effects of moral emotions on cooperative behaviour can only be understood if the specific moral emotion is known.