The aim of the present research aimed to study the mechanisms underlying the relationship between aggressive behaviour and individual levels of ability emotional intelligence (EI). We particularly focused on the mediator role of negative affect explaining this relationship. Three hundred and ninety-five participants took part in the study. Participants were assessed on ability EI (by the Mayer-Salovey-Caruso Emotional Intelligence Test), aggression (Buss-Perry Aggression questionnaire), and negative affect (the Positive and Negative Affect Schedule). Path analyses were used to explore which branches of the ability EI are directly related to the four aggression dimensions (physical aggression, verbal aggression, anger and hostility) and indirectly related via negative affect. The results revealed a negative relationship between ability EI and aggression, but this relationship was a function of multiple factors such as the performance level in each of the ability EI branches, the type of aggression studied, the mediator effect of NA, and gender. The emotional managing branch showed a direct effect on aggression, specifically this branch was directly related to physical, verbal, and hostility aggression. Moreover, the emotional perception branch was indirectly related to the four aggression dimensions (physical, verbal, anger, and hostility) through negative affect acting as mediator. The direction of these relationships was always negative, that is, greater ability EI was associated with lower levels of aggression, highlighting the strength of the association with physical aggression. Finally, results also showed interesting gender differences. Women possess greater EI abilities, higher levels of negative affect, less aggressive behaviour, and a lower relationship between negative affect and aggression compared with men. This research offers a better understanding of the psychological processes explaining aggression.
