The Effect of Group Decision Making on Cooperation in Social Dilemmas

A robust finding in social dilemma research is an increase in individual cooperative choice following group discussion about the dilemma. To elaborate the idea that this effect arises from the development of within-group consensus, groups of six made explicit group decisions about their subsequent individual choice. Perceived demonstrability of cooperativeness in the dilemma was manipulated through changes both to instructions and the incentives of the dilemma. As demonstrability decreased, so did the proportion of groups deciding to cooperate, leading to a reduction in the group discussion effect. Social decision scheme analysis supported the demonstrability-group decision hypothesis. The interaction between demonstrability, individual opinions and group process is proposed to explain the group discussion effect.