FEAR AND FITNESS - AN EVOLUTIONARY ANALYSIS OF ANXIETY DISORDERS

This article reviews the evolutionary origins and functions of the cap acity for anxiety, and relevant clinical and research issues. Normal a nxiety is an emotion that helps organisms defend against a wide variet y of threats. There is a general capacity for normal defensive arousal , and subtypes of normal anxiety protect against particular kinds of t hreats. These normal subtypes correspond somewhat to mild forms of var ious anxiety disorders. Anxiety disorders arise from dysregulation of normal defensive responses, raising the possibility of a hypophobic di sorder (too little anxiety). If a drug were discovered that abolished all defensive anxiety, it could do harm as well as good. Factors that have shaped anxiety-regulation mechanisms can explain prepotent and pr epared tendencies to associate anxiety more quickly with certain cues than with others. These tendencies lead to excess fear of largely arch aic dangers, like snakes, and too little fear of new threats, like car s. An understanding of the evolutionary origins, functions, and mechan isms of anxiety suggests new questions about anxiety disorders.