Ethological attempts to capture and measure offensive aggression point to two prominent hypotheses for the neural basis of violence. Aggression that serves as a reinforcer can be excessive, and certain schedules of reinforcement that allow aggression rewards also allow for examining brain and behavior during the anticipation of a fight. Quantifiable escalations in attack or the development of an atypical sequence of attacks and threats is useful for characterizing abnormal variations in aggression across species. In this review, we discuss translational models as they relate to pathological forms of offensive aggression and the brain mechanisms that underlie these behaviors.
Aggression is a phylogenetically stable behavior, and attacks on conspecifics are observed in most animal species.