We hypothesized that threats to people's social (i.e., group) identity can trigger deviant attitudes and behaviors. A correlational study and five experiments showed that experiencing or recalling situations associated with the devaluation of a social identity caused participants to endorse or engage in deviant actions, including stealing, cheating, and lying. The effect was driven by the tendency to construe social identity threats not as isolated incidents but as symbolic of the continuing devaluation and disrespectful treatment of one's group. Supplementing sociological approaches to deviance and delinquency, the results suggest the relevance and utility of a social-psychological account.