Integrating theory, research, and practical applications, this book provides a comprehensive examination of defense mechanisms and their role in both normal development and psychopathology. The author describes how children and adults mobilize specific kinds of defenses to maintain their psychological equilibrium and preserve self-esteem, particularly in situations of trauma or stress. Many lucid examples illustrate what these mechanisms look like in everyday life; the impact of age, gender, and personality differences; what happens when defenses are used maladaptively; and how they are affected by psychotherapy. Challenges in assessment are considered, and empirically supported instruments and approaches are discussed in depth. This book is divided into five parts. Part I, Defenses in Everyday Life, includes the following chapters: (1) Introduction; and (2) Development of Defenses. Part II, A Closer Look at Three Defenses, includes the next chapters in the book: (3) Denial; (4) Projection; and (5) Identification. Part III, Defense Mechanisms in Action, presents: (6) Defenses in Childhood: Stress and Psychopathology; (7) Stress and Defense Use in Adulthood; (8) Defenses and Personality; (9) Gender Differences and Defenses; and (10) Studying Defenses over Time: Longitudinal Studies. Part IV, Defenses and Psychopathology, includes: (11) Defenses and Psychopathology in Adult Community and Student Samples; (12) Defenses and Psychopathology in Adult Psychiatric Patients; (13) Defenses and Psychotherapy; and (14) Case Studies. The final part, Part V, Assessment of Defenses, includes the concluding chapters of the book: (15) Explaining the Defense Mechanism Manual; and (16) Other Approaches to Assessing Defense Mechanisms.