Habit, custom, and power: A multi-level theory of population health

► A new theoretical framework is offered to explain how the many elements included in existing conceptual models function. ► Patterns of behavior can be better explained by cognitive habits, than by rational choice theory. ► When cognitive habits are widely shared within a society, they take on a social ontology as custom. ► Custom evolves toward optimality through a process of natural selection. ► Social, economic, and political power exerts selective pressure for custom to evolve toward the interests of power.