The sound of silence in prisoner's dilemma and dictator games

Communication increases contributions to public goods. Our experimental results indicate that communication is not always required. Silent identification suffices to raise solidarity in prisoner's dilemma and dictator games. Increases in solidarity are not only due to expectations of reciprocity. While mutual identification induces individuals to converge to the social norm, the spread of the distribution of choices increases with one-way identification and with communication. As others are no longer faceless entities, one-way identification decreases social distance, inducing interaction-specific solutions. Communication allows more information to be transferred and, therefore, more scope for abandoning the norms. (C) 1999 Elsevier Science B.V. All rights reserved.