Collectivists “know themselves” better than individualists, in that they provide more accurate self-predictions of future behavior in situations with moral or altruistic overtones. In 3 studies, respondents from individualist cultures overestimated the likelihood that they would act generously in situations involving redistributing a reward (Study 1), donating money (Study 2), or avoiding rude behavior (Study 3), whereas collectivists were in general more accurate in their self-predictions. Both groups were roughly accurately in predicting the behavior of their peers. Collectivists were more accurate in their self-predictions than individualists even when both groups were sampled from the same cultural group (Study 4). Discussion centers on culturally specific motivations that may bias the accuracy of self and social insight.