Neurobiology of empathy and callousness: implications for the development of antisocial behavior.

Information on the neurobiology of empathy and callousness provides clinicians with an opportunity to develop sophisticated understanding of mechanisms underpinning antisocial behavior and its counterpart, moral decision-making. This article provides an integrated in-depth review of hormones (e.g. peripheral steroid hormones such as cortisol) and brain structures (e.g. insula, anterior cingulate cortex, and amygdala) implicated in empathy, callousness, and psychopathic-like behavior. The overarching goal of this article is to relate these hormones and brain structures to moral decision-making. This review will begin in the brain, but will then integrate information about biological functioning in the body, specifically stress-reactivity. Our aim is to integrate understanding of neural processes with hormones such as cortisol, both of which have demonstrated relationships to empathy, psychopathy, and antisocial behavior. The review proposes that neurobiological impairments in individuals who display little empathy are not necessarily due to a reduced ability to understand the emotions of others. Instead, evidence suggests that individuals who show little arousal to the distress of others likewise show decreased physiological arousal to their own distress; one manifestation of reduced stress reactivity may be a dysfunction in empathy, which supports psychopathic-like constructs (e.g. callousness). This integration will assist in the development of objective methodologies that can inform and monitor treatment interventions focused on decreasing antisocial behavior. Copyright 2009 John Wiley & Sons, Ltd.