Megías A, et al. - To further explore the mechanisms underlying the relationship between aggressive behaviour and individual levels of ability emotional intelligence (EI), 395 participants were assessed on ability EI, negative affect (NA), and aggression by the Mayer-Salovey-Caruso Emotional Intelligence Test, the Positive and Negative Affect Schedule, and the Buss-Perry Aggression questionnaires, respectively. Aggression and ability EI were noted to have a negative correlation. Multiple factors (the type of EI branches and aggression dimensions, the influence of NA, and gender) influenced this relationship. With aggression, emotional management ability demonstrated a direct relationship, while emotional perception ability presented an indirect relationship through the effect of NA. Furthermore, women demonstrated greater EI abilities, higher levels of NA, less aggressive behaviour, and a lower relationship between NA and aggression compared with men.