Many illnesses can be prevented or limited by altering personal behavior, and public health planners have turned to psychology for guidance in fostering self-protective activity. A social theory of personal action provides an integrative framework for applying psychology to public health, disclosing gaps in our current understanding of self-regulation, and generating guidelines for improving health promotion at the population level. A social action view emphasizes social interdependence and interaction in personal control of health-endangering behavior and proposes mechanisms by which environmental structures influence cognitive action schemas, self-goals, and problem-solving activities critical to sustained behavioral change. Social action theory clarifies relationships between social and personal empowerment and helps explain stages of self-change.