Ostracism’s negative consequences have been widely documented, but research has yet to explore the personality characteristics of its targets that precipitate ostracism. Based on theories of the functions of ostracism, we found that people are more willing to ostracize disagreeable targets than more agreeable targets (Studies 2 and 3). This outcome was mediated by participants’ interpersonal trust toward the target, and was especially strong for people who highly endorse fairness as a foundation for morality (Study 4). Ironically, the experience of ostracism induced a state of disagreeableness: the very characteristic that elicits ostracism from others (Study 5). This relationship was mediated by feelings of anger (Study 6). Findings indicate disagreeableness is a particularly negative outcome of ostracism, because it leads to further ostracism.