The Theory of planned behavior (TPB) is a psychological theory that predicts an individual’s intention to engage in a behavior at a given point in time and place. The theory intends to explain the exertion of self-control through the study of behavior. The theory of planned behavior (TPB) majors in components such as perceived behavioral control, subjective norms, and attitudes, which shape an individual’s behavioral intentions.

The theory has been integral to successfully predicting behavior such as drinking, substance abuse, health service utilization, and smoking among others. On the topic of components, behavioral control is the perception of an individual on the simplicity or difficulty of behavior. Subjective norm encompasses approval and acceptance of certain behavior by other people. Attitudes refer to a feeling toward someone or something either approving or disapproving the evaluation of the behavior of interest.

The TPB  comprises certain constructs that represent a person’s control over their behavior. They include; perceived power,  behavioral intention, perceived behavioral control, and subjective norms among others. The TPB is applicable in places such as health-related behavior, voting behavior, financial behavior, and environmental psychology.

Like any study or theory, TPB has its various disadvantages. Some of these disadvantages may be that the theory assumes that behavior results from a linear decision making process not accounting that it may change over time, it does not account for factors such as threat, mood, and past experience that may affect behavior, it does not consider the time frame between “intent” and “behavioral action” addressed by the theory, its does not account for environmental or economical factors that influence a person’s intention to enact a behavior, and finally the theory also assumes that a person has acquired the resources, means and opportunity to be successful in performing the desired behavior.