The mediating role of domain judgement in the relation between the Big Five and bullying behaviours

• Links between Big Five, domain judgement and bullying are evaluated in adolescents.
• All the Big Five except Openness are related to bullying.
• Consciousness affects judgement in all domains, Agreeableness only in moral domain.
• Only moral domain judgement affects involvement in bullying.
• Moral domain judgement explains in part the relation between Big Five and bullying.

Although many studies have shown that personality differences predict aggressive and antisocial behaviours, few studies have investigated how the Big Five (BF) affects involvement in school bullying and the mechanisms explaining this influence. Our aim was to investigate the relation between the BF and involvement in school bullying, hypothesising direct and indirect effects, through the mediation of judgement about rule-breaking in different domains (domain judgement). A sample of 339 adolescents (156 males and 183 females) completed the Big Five Questionnaire, a questionnaire evaluating moral, conventional and prudential domain judgement (D-RB) and self- and peer-reported measures of bullying. Our findings showed that adolescents higher on Neuroticism and Extraversion and lower on Agreeableness and Conscientiousness are more involved in bullying. Moreover, it emerged that only moral domain judgement is independently associated with bullying and mediates the relation between Conscientiousness and Agreeableness and the outcome. It was concluded that certain personality characteristics may facilitate the involvement of adolescents in bullying and that domain judgement could in part explain this relation: lower Conscientiousness and Agreeableness seem to be responsible for lower sensitivity to the moral rules that, in turn, can lead adolescents to be more involved in bullying.