What Is The Theory Of Planned Behavior In Behavior Change?


The Theory of Planned Behavior (TPB) is a psychological framework that aims to predict and explain an individual’s intention to engage in a specific behavior, based on their attitudes, subjective norms, and perceived behavioral control. Developed by Icek Ajzen in the late 1980s as an extension of the Theory of Reasoned Action, the TPB has become a widely used model for understanding and predicting a variety of human behaviors in diverse domains, including health, consumer behavior, and environmental actions.


The Theory of Planned Behavior was developed to address some limitations of the Theory of Reasoned Action, particularly the assumption that individuals always have volitional control over their actions. By introducing the concept of perceived behavioral control, the TPB acknowledges that individuals may face external constraints or limited resources that can influence their ability to perform a particular behavior.

Key Components

The Theory of Planned Behavior consists of three primary components that influence an individual’s intention to engage in a specific behavior:


The individual’s overall evaluation of the behavior, based on their beliefs about the outcomes or consequences associated with it. Attitudes can be positive (favorable) or negative (unfavorable) and are formed through a combination of cognitive (beliefs) and affective (feelings) processes.

Subjective Norms

The individual’s perception of social pressure or expectations from significant others (e.g., friends, family, or peers) to engage or not engage in a particular behavior. Subjective norms are influenced by normative beliefs (what important others think the individual should do) and motivation to comply (the desire to meet others’ expectations).

Perceived Behavioral Control

The individual’s belief in their ability to successfully perform the behavior, considering factors such as skills, resources, and external constraints. Perceived behavioral control is similar to the concept of self-efficacy and can have a direct effect on both intention and actual behavior.

These three components contribute to the formation of an individual’s behavioral intention, which is the immediate determinant of behavior in the TPB. The stronger the intention, the more likely the individual is to engage in the behavior, provided that they have the necessary resources and control over the behavior.


The Theory of Planned Behavior has been applied to a wide range of behaviors and settings, such as health promotion, environmental conservation, consumer decision-making, and workplace performance. By identifying the factors that influence individuals’ intentions and actual behaviors, researchers and practitioners can develop targeted interventions that address the specific components of the TPB. For example, health promotion campaigns might focus on changing attitudes towards a healthy behavior, increasing social support, or enhancing individuals’ perceived control over their actions.


The Theory of Planned Behavior is a robust and flexible framework for understanding and predicting human behavior across various domains. By examining the interplay between attitudes, subjective norms, and perceived behavioral control, the TPB can inform the design of effective interventions that target the factors most likely to influence individuals’ intentions and ultimately, their actions. The TPB continues to be a valuable tool for researchers and practitioners in behavioral science, providing insights into the complex processes that underlie human decision-making and behavior.

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