Theory of Planned Behavior

Based on the theory of reasoned action, the theory of planned behavior (TPB) was first described by social psychologist Icek Ajzen in 1985. The theory posits that someone’s behavior is determined by their intention to perform that behavior and in some cases, their perceived level of behavioral control.

Understanding the theory of planned behavior

The theory of planned behavior posits that all behaviors are conscious, planned, and reasoned. In other words, it assumes that the individual has deliberate control over their actions.

Someone’s intention to perform a specific behavior is fundamental to the theory of planned behavior. In a subsequent 1991 article in the journal Organizational Behavior and Human Decision Processes, Ajzen described intention as the “motivational factors that influence a behavior; they are indications of how hard people are willing to try, of how much an effort they are planning to exert, in order to perform the behavior.

Since the theory helps practitioners understand and predict human behavior, its applications are almost unlimited.

Nevertheless, it is particularly popular in healthcare contexts such as family planning, addiction, birth control, and disease prevention.

TPB has also been applied to entrepreneurial intention (EI). In a study of 528 business administration undergraduates in Turkey, researchers found that students with prior start-up experience were more likely to engage in entrepreneurial behavior because of increased levels of self-efficacy and personal attitude toward entrepreneurship itself.

From the results, the researchers noted that this behavioral predictor could be harnessed by policy-makers as a way to drive innovation and innovative thinking within their respective economies.

What influences behavioral intention in the TPB?

Behavioral intention is influenced by three factors.

1 – Personal attitudes 

The sum of an individual’s attitudes, knowledge, and prejudices toward a specific behavior (both positive and negative). 

Someone’s attitude toward smoking, for example, may include that tobacco is a relaxing pastime that also makes them smell and wake up with a hacking cough in the morning.

2 – Subjective norms 

The perception of the attitudes of other people toward the behavior. The smoker may perceive that their friends and family think their habit is addictive and harmful to their health.

3 – Perceived behavioral control 

The extent to which the individual believes they can control their behavior. This may be influenced by factors such as their perceived level of ability and determination or the number of support services available to them.

Importantly, TPB believes this perception affects:

  • The individual’s intention to behave a certain way. That is, the more control one believes they have over their behavior, the stronger the intention to perform that behavior.
  • The behavior directly. When an individual perceives that there is more control, they tend to exert effort for longer to succeed.

How can the theory of planned behavior be used?

The theory of planned behavior is the most used model in healthcare psychology and intervention campaigns. 

If we return to the previous example of the smoker, let’s imagine that the individual is 18 years old and part of a friend group where most others also smoke. Based on this, the teenager may come to the mistaken conclusion that smoking is the norm.

Using TPB, the government could develop an anti-smoking campaign where the true percentage of teenage smokers was clarified.

In America, for example, a 2021 CDC study found that just 1.9% of high school students had smoked cigarettes in the previous 30 days.

When the teenage smoker is exposed to the true extent of smoking among those in their age group, their subjective norm will likely change. In other words, they will perceive that the vast majority of people don’t smoke and potentially see their behavior as undesirable.

Key takeaways:

  • The theory of planned behavior posits that all behaviors are conscious, planned, and reasoned. The theory posits that someone’s behavior is determined by their intention to perform that behavior and in some cases, their perceived level of behavioral control.
  • The theory of planned behavior helps practitioners understand and predict human behavior, so its applications are almost unlimited. It is mostly used in healthcare contexts but is also seen in entrepreneurship, innovation, and economic development.
  • Behavioral intention in the theory of planned behavior is determined by three variables: personal attitudes, subjective norms, and perceived behavioral control. By understanding these variables, organizations and governments can predict behavior and create interventions that nudge individuals toward more beneficial behaviors.

Connected Business Concepts


As highlighted by German psychologist Gerd Gigerenzer in the paper “Heuristic Decision Making,” the term heuristic is of Greek origin, meaning “serving to find out or discover.” More precisely, a heuristic is a fast and accurate way to make decisions in the real world, which is driven by uncertainty.

Bounded Rationality

Bounded rationality is a concept attributed to Herbert Simon, an economist and political scientist interested in decision-making and how we make decisions in the real world. In fact, he believed that rather than optimizing (which was the mainstream view in the past decades) humans follow what he called satisficing.

Second-Order Thinking

Second-order thinking is a means of assessing the implications of our decisions by considering future consequences. Second-order thinking is a mental model that considers all future possibilities. It encourages individuals to think outside of the box so that they can prepare for every and eventuality. It also discourages the tendency for individuals to default to the most obvious choice.

Lateral Thinking

Lateral thinking is a business strategy that involves approaching a problem from a different direction. The strategy attempts to remove traditionally formulaic and routine approaches to problem-solving by advocating creative thinking, therefore finding unconventional ways to solve a known problem. This sort of non-linear approach to problem-solving, can at times, create a big impact.

Moonshot Thinking

Moonshot thinking is an approach to innovation, and it can be applied to business or any other discipline where you target at least 10X goals. That shifts the mindset, and it empowers a team of people to look for unconventional solutions, thus starting from first principles, by leveraging on fast-paced experimentation.


The concept of cognitive biases was introduced and popularized by the work of Amos Tversky and Daniel Kahneman in 1972. Biases are seen as systematic errors and flaws that make humans deviate from the standards of rationality, thus making us inept at making good decisions under uncertainty.

Dunning-Kruger Effect

The Dunning-Kruger effect describes a cognitive bias where people with low ability in a task overestimate their ability to perform that task well. Consumers or businesses that do not possess the requisite knowledge make bad decisions. What’s more, knowledge gaps prevent the person or business from seeing their mistakes.

Occam’s Razor

Occam’s Razor states that one should not increase (beyond reason) the number of entities required to explain anything. All things being equal, the simplest solution is often the best one. The principle is attributed to 14th-century English theologian William of Ockham.

Mandela Effect

The Mandela effect is a phenomenon where a large group of people remembers an event differently from how it occurred. The Mandela effect was first described in relation to Fiona Broome, who believed that former South African President Nelson Mandela died in prison during the 1980s. While Mandela was released from prison in 1990 and died 23 years later, Broome remembered news coverage of his death in prison and even a speech from his widow. Of course, neither event occurred in reality. But Broome was later to discover that she was not the only one with the same recollection of events.

Crowding-Out Effect

The crowding-out effect occurs when public sector spending reduces spending in the private sector.

Bandwagon Effect

The bandwagon effect tells us that the more a belief or idea has been adopted by more people within a group, the more the individual adoption of that idea might increase within the same group. This is the psychological effect that leads to herd mentality. What is marketing can be associated with social proof.

Read Next: BiasesBounded RationalityMandela EffectDunning-Kruger

Read Next: HeuristicsBiases.

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