Aggression and violence are social behaviors that exact a significant toll on human societies. Individuals with aggressive tendencies display deficits in effortful control, particularly in affectively charged situations. However, not all individuals with poor effortful control are aggressive. This study uses event-related potentials (ERPs) recorded from a large sample (n = 75 undergraduates) to decompose the chronology of neural mechanisms underlying the ability to effortfully-control behavior, and then explores whether deficits in these cognitive functions might then lead to aggressive behavior. This study investigated which ERPs moderate the effortful control - aggression association. We examined three successive ERP components, the P2, N2, and P3, which have been associated with attentional orienting, response conflict, and working memory updating, for stimuli that required effortful control. N2 amplitudes were larger for trials requiring a switch from a preplanned action strategy than trials where a preplanned action strategy was followed. Furthermore, results indicated that N2 activation, but not P2 or P3 activation, moderated the relationship between effortful control and aggression. Our results suggest that small (less negative) N2s moderate the association between effortful control and aggression. These effects were present only in negative contexts, and only for high-conflict trials. Results suggest that individual differences in neural processing efficiency contributes to the execution of effortfully controlled behavior and avoidance of aggression.