The lives of others: Third parties' responses to others' injustice.

This research takes a moral perspective to studying third parties' reactions to injustice as a function of their moral identity. Drawing from theories of deontic justice, moral intuition, moral heuristics, and moral identity, we develop and test a model of the moral underpinnings of third parties' reactions to injustice. First, we compare third parties' responses with interpersonal, distributive, and procedural justice violations. We hypothesize that third parties are more likely to intuit that interpersonal justice violations are morally wrong, compared with distributive and procedural justice violations. As a result, third parties are more likely to experience stronger moral anger and punish violators in response to interpersonal transgressions compared with distributive and procedural justice transgressions. Second, we test the proposition that third parties with a strong moral identity will react more strongly to justice violations than third parties with a comparatively weak moral identity. Results from 3 studies support these predictions.