Hormonal factors influence aggression in response to peer victimization and diet.

Adolescents with high or low levels of testosterone and cortisol are more likely to react aggressively when victimized or provoked by peers, according to a study in Spain. The study also found that girls' aggressive responses were associated with the ratio of these two hormones. The research sheds light on the link between hormone concentrations and complex behavior, but has limitations, including that hormone concentration measures were taken only during one time of the day and assessments of victimization and perpetration were exclusively based on self-reports.