Some theories of health behavior focus on proximal cognitive predictors of behavior, some focus on expectancy-value formulations, some focus on social support and bonding processes, some focus on social learning processes, and some point toward personality and intrapersonal processes. Very few extant theories of health behavior incorporate several of these viewpoints, and those that do are limited in various ways. We propose a new comprehensive theory that integrates constructs from all previous theories. Triadic influence theory includes seven “tiers” of “causes” of behavior that range from very proximal to distal to ultimate, and three “streams of influence” that flow through the seven “tiers”: (I) cultural- environmental influences on knowledge and values, influencing attitudes, (2) social situation-context influences on social bonding and social learning, influencing social normative beliefs, and (3) intrapersonal influences on self determination / control and social skills, leading to self-efficacy. In addition to the direct influences of these streams, there are important inter-stream effects and influences that flow between tiers. The theory is intended to account for factors that have direct effecls as well as indirect effects on behavior. It is also intended to account for both new behaviors and regular behavior. Experiences with related behaviors and early experiences with a new behavior lead to feedback loops through all three steams adding to the prior influences of these streams. Our integration of existing theories leads to a meta-theoretical view that suggests higher order descriptions and explanations of health behavior, leads to a new and comprehensive view of health behavior change, and suggests new approaches for health promotion and disease prevention.
