This document discusses various aspects of addiction including defining addiction, models of addictive behavior, and factors that influence addiction. It covers biological, cognitive, and social learning theories of addiction. The biological model emphasizes genetics and brain chemistry, noting specific genes linked to addiction initiation and maintenance. Cognitive models explore how expectancies and faulty thinking patterns can lead to addiction. Social learning theory examines how addiction can develop through observational learning and reinforcement. The document also addresses individual differences in vulnerability to addiction like personality and stress, as well as social influences of peers, age, and media portrayals of addictive behaviors.