The present research proposed that one social-cognitive root of adolescents' willingness to use relational aggression to maintain social status in high school is an entity theory of personality, which is the belief that people's social status-relevant traits are fixed and cannot change. Aggregated data from three studies (N=882) showed that first-year high school adolescents in the U.S. who endorsed more of an entity theory were more likely to show cognitive and motivational vigilance to social status, in terms of judgments on a novel social categorization task and reports of goals related to demonstrating social status to peers. Those with an entity theory then showed a greater willingness to use relational aggression, as measured by retrospective self-reports, responses to a hypothetical scenario, and a behavioral choice task. Discussion centers on theoretical and translational implications of the proposed model and of the novel measures.