Book excerpt: Essentials of Health Behavior: Social and Behavioral Theory in Public Health, Third Edition provides the groundwork for understanding, assessing, and effectively applying theories of human behavior within the practice of public health. In clear and accessible language, this text provides the student with a background of the kinds of social and behavioral theories that guide our understanding of health related behavior and form the background for health promotion and prevention efforts. Filled with real life examples and profiles, the text explores some of the ways in which these theories and approaches are used in applied health promotion efforts.