Noblesse Oblige? Moral Identity and Prosocial Behavior in the Face of Selfishness

What makes individuals conform or diverge after observing prosocial or selfish behavior by others? We study experimentally how social comparison (observing a peer’s behavior) interacts with identity motives for cooperation. Participants play two games. We increase the strength of the identity motive by inducing subjects in a treatment condition to infer their identity from behavior in the first game. Cooperators who observe a peer defect donate 28% more to their unknown partner in the second game in the treatment than in the control group. Our results are consistent with the predictions of Bénabou and Tirole (2011), and show that the "suckerto- saint effect" identified by Jordan and Monin (2008) can have important behavioral consequences.