From night owl to angry bird: Investigating the association between chronotype and aggression

Recent attempts to understand the sleep-aggression relationship highlight the importance of the role of cognition. A related but separate concept of sleep, chronotype (i.e., sleep timings) has also been suggested to contribute to levels of aggression. The current study explores the relationship between chronotype, sleep quality, hostility, aggression, and intimate partner violence (IPV). Two hundred and eight participants completed online questionnaires to explore the contribution of hostility and sleep quality as mediators of the chronotype-aggression relationship. Findings indicate that chronotype was associated with levels of aggression, with those with later chronotypes reporting higher levels of aggression. Two mediation models revealed that this relationship was mediated by hostile cognitions (i.e., hostile attribution biases), and partially mediated by sleep quality. The chronotype-IPV relationship was explored, but the association was not significant. Findings indicate that those with late chronotypes may be more susceptible to hostile cognitions which leads to aggressive outcomes. However, there may be additional factors contributing to this relationship when considering violence in relationships. Aggression-focused interventions may benefit from dissecting an individual’s sleep patterns to reduce hostile cognitions and future research would benefit from objective measures of both chronotype and aggression.