Integrating theory, research, and practical applications, this timely 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.