Background: The relationship between psychopathic traits and aggression in children may be explained by their reduced sensitivity to signs of distress in others. Emotional cues such as fear and sadness function to make the perpetrator aware of the victim's distress and supposedly inhibit aggression. As children high in psychopathic traits show a reduced sensitivity to others' distress, these important interpersonal signals cannot perform their aggression inhibiting function. The present experiment tested the hypothesis that aggression in children with psychopathic traits can be attenuated by making distress cues more salient. Methods: N = 224 participants from the community (53 % boys, M age = 10.81 years, SD= 0.92) played a computer-based competitive reaction-time game against a simulated opponent by blasting him or her with loud noise through a headphone. The salience of the opponent's distress was increased for half of the participants (randomly selected) by a written message expressing his or her fear. Psychopathic traits were assessed using the Youth Psychopathic traits Inventory - Child Version (Van Baardewijk et al., 2008). Results: As expected, regression analysis showed that psychopathic traits were strongly related to aggression in the no distress condition but not in the distress condition. Thus, the relation between psychopathic traits and aggression depended upon the salience of the opponent's distress. Conclusions: It was concluded that children with psychopathic traits are indeed prone to act aggressively, but also that this aggression is dynamic and is dependent upon circumstances. Their aggression can be attenuated by a salient display of others' distress. These results suggest that empathy based treatment techniques may reduce aggression in children with psychopathic traits. © 2009 Association for Child and Adolescent Mental Health.