Aggressive behavior has been repeatedly observed in patients with schizophrenia and related psychotic disorders. However, there is little known about the underlying psychological mechanisms, especially the role of social cognition, in contributing to the exhibition of aggression. The aim of this study was to investigate whether aggression was associated with theory of mind (ToM) deficiency and the presence of hostility bias. Thirty individuals with a DSM-IV-TR diagnosis of schizophrenia or other psychotic disorders were asked to complete the Faux Pas Recognition Test, the Ambiguous Intentions Hostility Questionnaire, and the Conflict Tactic Scale. Results suggested that psychotic patients with predominately referential or persecutory delusions were more susceptible to theory of mind anomalies and hostility bias, and had a higher frequency of the demonstration of aggressive behavior relative to patients with auditory hallucination and remitted patients. Correlational analysis revealed significant associations among ToM, hostility bias, and aggression. Multiple regression analyses showed that hostility bias was neither a mediator nor a moderator in the relationship between ToM and aggression. The present study provided preliminary evidence that social cognition and social-cognitive attributional styles are related to the demonstration of aggressive behavior. / published_or_final_version / Clinical Psychology / Master / Master of Social Sciences