This book investigates the interplay of psychological and physical aggression between partners. It examines the history of research in this area, discusses new, cutting-edge studies, and suggests promising applications in clinical settings. Different levels of severity and types of aggression are explored, illustrating that for both risk factors and interventions, "one size does not fit all." This book is suitable for partner aggression/violence researchers and intervention providers, clinical psychologists, counseling psychologists, couples therapists, social workers, and professionals working in victims' rights and public health.