Fear, Anxiety, and Defensive Behaviors in Animals

Abstract

Defensive behaviors are a group of evolved responses to threat. They include flight, freezing, defensive threat, defensive attack, and risk assessment. The type of defensive behavior elicited in a particular situation depends on features of both the threat and the situation. Although defensive behaviors have a substantial unlearned component, they are rapidly acquired to previously neutral stimuli associated with predator or pain. Both behavioral analyses and differential responsivity of particular defensive behaviors to anxiolytic and panicolytic drugs suggest that individual defenses may be selectively associated with particular classifications of anxiety disorders.