That Still, Small Voice: Commitment to Cooperate as an Internalized Versus a Social Norm.

Recent research suggests that group discussion of a social dilemma may increase cooperative behavior because group members honor the commitments they make during the group discussion. This article asks whether people honor such commitments because of the social consequences of violating them or because of the internal personal consequences of doing so. Experiment 1 replicated and extended previous research showing that the anonymity of one's cooperative/noncooperative choice does not moderate the effect of group discussion. Experiment 2 examined the possibility that commitments to cooperate were kept due to mindless adherence to a prior decision, rather than to an internalized norm. Contrary to the former possibility, enhancing mindfulness did not moderate the effect of group discussion. The scope and implications of personal norms of commitment are discussed.