Neural and Cognitive Bases of Human Punishment Behavior
Ginther, Matthew Raymond
Punishment undergirds large-scale cooperation and helps dispense criminal justice. Despite its importance, little is known about the brain mechanisms that support punishment decision-making as well as the influence of affect on these brain systems. Across four studies I explore these twin questions. Prior behavioral studies indicate that the mental state of the offender and the harm he caused are the primary factors that influence the outcome of a punishment decision. Chapter one examines how people assess the mental states of offenders, evaluate the harms they caused, and integrate those two components into a single punishment decision. Using a new design, we isolated these three processes, identifying the distinct brain systems and activities that enable each. Additional findings suggest that the amygdala plays a crucial role in mediating the interaction of mental state and harm information, whereas the dorsolateral prefrontal cortex plays a crucial, final-stage role, both in integrating mental state and harm information and in selecting a suitable punishment amount. Chapter two builds on chapter one to explore the role of affective arousal in shifting the outcome of the punishment decision. Specifically, we use a subliminal cue that is known to target activation in the amygdala and assess the extent to which there may be a causal link between the amygdala and punishment decisions. In chapters three and four I expand on the role of emotional affect in third-party punishment decision-making by parsing the specific emotional state that is associated with mediating the relationship between norm violations and punishment outcomes. Inconsistent with the popular notion that punishment decisions are based on purely cognitive reasoning, intended harmful acts elicit strong emotional reactions in third-party decision makers. While these emotional responses are now believed to affect punishment decision-making, there is much debate about what emotions may be fueling this behavior. Chapter three demonstrates that–unlike anger, contempt, and disgust–moral outrage is evoked by the integration of culpable mental state and resulting harms, and it alone mediates the relationship between this integrative process and punishment decisions. Chapter four demonstrates that moral outrage appears to be selective for third-party norm violations.