Can political discussion help individuals improve their political decisions? Formal deliberation often helps citizens overcome their political ignorance, but recent work suggests informal, everyday discussion often fails to promote these benefits. I argue that recent informal discussion research has investigated contexts in which discussants hold a narrow range of motivations, which differ from those held in many real-world conversations. I develop and test a theory explaining how motivations influence the efficacy of political discussion. The analysis examines a small-group experiment, which randomly assigns incentives to alter subjects’ (1) strength of partisan predispositions toward two computer-generated candidates, (2) motivations to form accurate judgments about these candidates, and (3) motivations to provide accurate information to fellow subjects. The results suggest that previous informal discussion research generalizes well to individuals holding elevated partisan motivations, but underestimates discussion’s civic capacity for individuals holding elevated accuracy and, especially, prosocial motivations.