The Theory of Planned Behavior (TPB) is a psychological framework that connects an individual's beliefs to their subsequent actions. At its heart, the theory proposes that three main elements—attitude, subjective norms, and perceived behavioral control—collectively shape a person's intentions to behave in a certain way. These behavioral intentions are considered the most direct predictors of human social behavior. The TPB has proven useful in understanding
various behaviors, from college students' financial management to health-related decisions and environmental actions.
Foundations and Core Components
The TPB originated from the Theory of Reasoned Action (TRA), which was first introduced in 1980 by Martin Fishbein and Icek Ajzen. The TRA itself was built upon various theories concerning attitude and attitude change, including learning theories, expectancy-value theories, attribution theory, and consistency theories. According to the TRA, if an individual views a suggested behavior positively (attitude) and believes that important people in their life want them to perform that behavior (subjective norm), their motivation to perform the behavior will be stronger, making them more likely to act.
However, research indicated that behavioral intention alone does not always lead to actual behavior, especially when an individual's control over the behavior is incomplete. To address this, Ajzen introduced the concept of perceived behavioral control, thereby extending the TRA into the TPB. This addition aimed to better predict actual behavior by accounting for the individual's belief in their ability to perform a given action.
Perceived Behavioral Control and Self-Efficacy
Perceived behavioral control refers to the extent to which a person believes they can successfully perform a specific behavior. This concept is rooted in Bandura's self-efficacy theory, which he proposed in 1977 as part of social cognitive theory. Self-efficacy is defined as a person's confidence or expectation that they can master a behavior or achieve a goal. Bandura distinguished between self-efficacy, which is the conviction that one can successfully execute the behavior needed to produce a desired outcome, and outcome expectancy, which is a person's estimation that a given behavior will lead to certain results.
Bandura emphasized that self-efficacy is a crucial precondition for behavioral change, as it is key to initiating coping behavior. In the context of TPB, perceived behavioral control is essentially the perception of how easy or difficult a particular behavior is to perform. It is linked to control beliefs, which are beliefs about factors that might help or hinder the performance of the behavior. The theory suggests that people are much more likely to intend to perform behaviors when they feel confident in their ability to do so successfully.
Interplay of Components and Behavioral Prediction
The TPB posits that attitude toward the behavior, subjective norms, and perceived behavioral control combine to form a behavioral intention. Generally, a strong intention to perform a behavior is expected when an individual has a favorable attitude toward it, when this attitude aligns with relevant social norms, and when the individual perceives a high level of control over the behavior. Given sufficient actual control over the behavior, the individual is then expected to carry out their intentions when the opportunity arises.
Perceived behavioral control is thought to influence actual behavior in two ways: directly and indirectly through behavioral intention. This means that not only does a person's belief in their ability to perform a behavior directly impact whether they do it, but it also shapes their intention to do so. The TPB has been widely applied in various fields, demonstrating its utility in understanding and predicting human actions across diverse contexts, from health interventions to environmental psychology and financial decision-making.
