Book excerpt: Social skills are critical to psychological adjustment across the lifespan. These skills are necessary for attaining a variety of important social, emotional, and interpersonal goals. Social skill definits and resulting negative social interactions are associated with a wide variety of adjustment problems and psychological disorders. Social Skills across the Life Span: Theory is a comprehensive social skills volume providing in-depth coverage of theory, assessment, and intervention. Divided into three major sections, the volume begins with the definition of social competence, developmental factors, and relations to adjustment. This is followed by coverage of general assessment and intervention issues across the lifespan. In the third section, program developers describe specific evidence-based interventions.