Background: Early exposure to trauma and stressors can hinder development and accumulate stress over one's lifetime, leading to adverse long-term outcomes. Objective: This study aims to investigate whether individuals exhibiting aggressive behavior may have been victims of emotional abuse and/or neglect during childhood. These experiences profoundly impact development, persisting into adulthood. Four hypotheses were formulated to guide the investigation. Methods: The sample comprised 615 Portuguese adults aged 18 and above. Data collection utilized various instruments including a sociodemographic questionnaire, the Impulsive and Premeditated Aggression Scale, the Life History of Aggression Scale, the Childhood Adversity History Questionnaire, the Difficulties in Emotional Regulation Scale, the Personality Inventory, and the Triarchic Psychopathy Measure. Results and Conclusions: The hypotheses were confirmed, indicating a positive correlation between childhood emotional abuse/neglect and adult aggressive behavior, emotional regulation challenges, elevated neuroticism, openness to experience, boldness, disinhibition, and meanness. Also, emotional regulation difficulties, personality traits, and psychopathy fully mediate the relationship between childhood maltreatment and impulsive/ premeditated aggression, as well as between a history of aggression and impulsive/ premeditated aggression.