Theory Of Planned Behavior (TPB)

The Theory of Planned Behavior (TPB), as used in psychology, suggests a link between behavior and beliefs. This theory, proposed by researcher Icek Ajzen, attempts to explain deliberate human behaviors that individuals have the ability to control. This theory improves on the predictive power of the Theory of Reasoned Action (TRA) .

The TRA was proposed by Ajzen and Martin Fishbein in 1967 in an attempt to explain the relationship between attitudes and behavior in human activity. TRA is used to predict how an individual will behave based on their behavioral intentions and attitudes. The intersection of these these two constructs is that they together can be used to predict how someone will behave - it depends on the on the desired outcome that results from performing a particular behavior.

As an example, someone may decide and plan to steal something with the knowledge that they can sell or pawn the stolen item for money. The main focus of the TPB is behavioral intent which is influenced by the attitude about behavioral likelihood - attitudes about whether the behavior will have the predicted outcome and judging the pros and cons of that outcome. The TPB states that behavioral results depends on both motivation and ability. The TPB is used to not only explain but also predict health behaviors such as smoking, drinking, substance use, and healthcare visits. This theory proposes there are six factors that influence an individual's actual control over their behavior: behavioral intention, subjective norms, social norms, attitudes, perceived behavioral control, and perceived power.