Theory of Planned Behavior

Have you ever wondered what causes an individual to act the way they do? Understanding what causes behavior has fascinated psychologists for decades. Many models have been proposed to explain behavior. One such model of behavior—the Theory of Planned Behavior (TPB) is a theory that explains how a person’s beliefs are linked to their behavior.

History of the Planned Behavior Theory

The Theory of Planned Behavior was first argued for by a Social Psychologist by the name of Icek Ajzen in 1985. Azjen released an article titled “From intentions to actions: A theory of planned behavior” where he argued that human behavior is typically the result of well formulated plans. 

For example, in his article he described how before a person attends a concert they purchase tickets, change their clothes, call a cab, and head to the concert venue. All of these are planned actions or behaviors.

Theory of Reasoned Action

Planned Behavior Theory was developed from the Theory of Reasoned Action which claimed that an individual’s choice to engage in a behavior is based on their expected results of the outcomes of that behavior. Reasoned Action Theory suggested a relationship between attitudes and human actions. The theory held that if an individual believes a behavior will lead to positive outcomes, then they will have a more positive attitude about that behavior and are more likely to engage in that behavior.

The Theory of Reasoned Action was proposed by Icek Ajzen and Martin Fishbein in 1967. Critics of the theory argued that attitude theories were not good indicators of human behavior. Fishbein and Ajzen expanded on the theory to overcome these objections in the Theory of Planned Behavior. 

Self-Efficacy Theory

Planned Behavior Theory also expands on several concepts from Self-Efficacy Theory. Self-Efficacy Theory was first proposed by Albert Bandura in 1977. The theory argues that a person’s belief about how well they can execute a course of action influences the successful outcome of that action. So if an individual believes that they are very good and will succeed at something, they will be more likely to work harder and thus are more likely to succeed in the action they are taking. 

Planned Behavior Theory

The Theory of Planned Behavior took expanded on the Theory of Reasoned Action and Self-Efficacy Theory to explain behavior. The theory held that behavioral intentions are influenced by the attitude about the likelihood that the behavior will have the desired outcome. The theory also argues that the subjective evaluation of the benefits and risks of a behaviors outcomes also influence behavior.

Key Concepts

In TPB (Theory of Planned Behavior) there are six important concepts that are used to represent a person’s control over their behavior:

Normative Belief – an individual’s belief about social normative pressures and other relevant ideas about whether they should or should not perform a behavior

Subjective Norm – an individual’s perception about a behavior that is influenced by the judgement of close others (such as girlfriend, spounds, parents, friends)

Control Belief – an individual’s beliefs about factors that may improve or impede performance of a behavior

Perceived Behavioral Control – an individual’s perception of how easy or difficult it is to perform a certain behavior. Perceived behavioral control is seen as the total sum of the individuals control beliefs. 

Behavioral Intention – an individual’s readiness to perform a certain behavior. This is based on the individual’s attitude about the behavior, subjectives norms, and perceived behavioral control. 

Behavior – an individuals observed response in a given situation.

The Model of Planned Behavior Theory

TPB argues that human behavior takes three things into consideration: behavioral beliefs, normative beliefs, and control beliefs. Behavioral beliefs result in either a positive or negative attitude toward the behavior, normative beliefs result in a subjective norm, and control beliefs lead to perceived behavioral control.

When you combine the attitude about a given behavior, subjective norm, and perceived behavioral control, you get the formation of behavioral intention. 

The more positive attitude about a given behavior and the subjective norm, and the greater the perceived behavioral control, the stronger a person’s intention to execute that behavior should be. 

Strengths of The Theory of Planned Behavior

One aspect of TPB that is considered strong is the fact that the Theory of Planned Behavior can explain social behavior by considering social norm as factor. Several studies have shown that TPB improves the prediction of intention in a variety of health related fields. 

Weakness of The Theory of Planned Behavior

Critics have argued against the theory for several reasons. One reason is that the theory does not account for an individuals needs before engaging in a behavior. For example a person might have a very positive attitude about something and still not engage in a behavior, because other preconditions are not met. 

Say an individual really likes caesar salad. They have a very positive attitude about caesar salad, but they don’t eat it. Because they are not hungry. The theory of TPB does not account for hunger being a precondition of behavior. Which is an important flaw in the theory. 

Conclusion

The Theory of Planned Behavior is a useful theoretical framework for predicting and explaining human behavior. The theory originated from Social Psychologist Ajzen as an expansion of Planned Behavior Theory and Self-Efficacy Theory. 

The theory maintains that certain beliefs result in either a positive or negative attitude about a behavior. The attitude about a behavior, subjective norm, and perceived behavioral control, when combined give you the behavioral intention. The more positive attitude about a given behavior and the subjective norm, and the greater the perceived behavioral control, the stronger a person’s intention to perform that behavior should be. 

The theory has several strengths and has proven useful in predicting behavior in certain fields, but it is not without its limitations. One strong argument is that it does not take into account the needs of an individual prior to performing behavior. 

Sources:

https://en.wikipedia.org/wiki/Theory_of_planned_behavior
https://en.wikipedia.org/wiki/Icek_Ajzen
https://link.springer.com/chapter/10.1007/978-3-642-69746-3_2
https://en.wikipedia.org/wiki/Self-efficacy