Testosterone and Human Aggression

Abstract One of the most widely studied biological correlates of aggressive behavior is the steroid hormone testosterone. Although traditional wisdom might suggest that individuals with more testosterone are more likely to be aggressive, research over the past several decades has identified important contextual, individual difference, and methodological variables that are key moderators of any such effect. In this chapter, we review literature examining how aggression is linked with baseline levels of testosterone, how testosterone fluctuates rapidly within the context of human competitive behavior, and how such competition‐induced hormonal fluctuations serve to potentiate ongoing and/or future aggressive behavior. The neuroendocrine mechanisms underlying such complex social behavior are discussed from research conducted within humans as well as nonhuman species, providing comparative clues as to the adaptive nature of such intricate systems.