Neurobiological Bases of Aggression

Aggression might best be defined broadly as an expression or action intended to harm another. The closely related notion of violence refers to a physical or possibly a psychological attempt to harm another. Various criminal codes provide relatively nuanced guidelines concerning boundaries across which expressions of harm become criminal offenses. Psychologists have traditionally examined aggression from different perspectives through legal (e.g., murder, assault), motivational (e.g., sexual assault, revenge), personal (e.g., psychopathy), or situational (e.g., proactive, reactive) lenses. More recently, some researchers have reported differential characteristics of brain structure and blood flow in different criminal types. This entry presents an alternate viewpoint that attempts to integrate these diverse perspectives into a coherent psychobiological model, that is, the biological basis of behavior and mental processes.