Four questions concerning anxiety seem important to us. First, what is the nature of the conditions that bring anxiety into being—what generates anxiety in the person who is experiencing it? Second, what are the physiological and neurological mechanisms by which anxiety occurs? Third, how do people respond when they experience anxiety? Fourth, how should dysfunctional responses to anxiety be dealt with clinically? Our work has emphasized most strongly the third of these questions, and this chapter focuses primarily on that question.