Theory of Reasoned Action
This theory is centered on the concept of behavioral intent. Specifically, before actual action takes place (i.e., before a new diet is tried) there is a mental formulation of intent which is influenced by attitudes toward the behavior/action and by perceptions of the social norms favorable to the behavior.
These attitudes, in turn, are also influenced by one’s confidence in achieving the expected outcome/result of the action and by the attitude toward that outcome/result. Perception of social norms around the action is influenced by beliefs about the strength of others’ opinions and the person’s own motivation to comply with those perceived opinions.
Often, this theory is the foundation for health interventions that intend to establish a social norm for a positive health behavior (e.g., exercise) for a targeted group. Using a social norm approach for health promotion attempts to influencing others to want to try, master and adhere to that social norm.