In trying to determine the differences between intention and behaviour, Fishbein and Ajzen (1975) came up with the theory of reasoned action, suggesting behaviour results from the individual’s intention to perform that specific behaviour. Most individuals decide their intention towards a behaviour well in advance, and that intention is the most accurate predictor of whether or not the individual will carry out that behaviour.

• The explanation will open with the definition of the Theory of Reasoned Action.
• A diagram of the Theory of Reasoned Action is presented, along with an example of the Theory of Reasoned Action.
• The application of the Theory of Reasoned Action is reviewed.
• We will discuss the strengths and limitations of the Theory of Reasoned Action, followed by a brief discussion on how the Theory of Reasoned Action developed into the more modern Theory of Planned Behaviour.

Fig. 1 - The theory of reasoned action explores intentions behind behaviours

Theory of Reasoned Action Definition

The theory of reasoned action was proposed by Fishbein and Ajzen (1975) in an attempt to explain how human behaviour can be foreshadowed and predicted by intention. The theory has two basic assumptions. It assumes that people always behave rationally and that humans always use all the information available to them.

According to the theory of reasoned action, the most important factor that influences whether or not a behaviour will take place is the individual's intention.

• The bigger the intention, the more likely the behaviour will happen.

The intention is composed of two other factors: attitudes towards behaviour and subjective norms.

• First, individuals assess the consequences associated with performing such behaviours. This would involve the individual asking him/herself; what are the consequences that come with performing such behaviours?
• And second, individuals evaluate the effect of the consequences, which would be assessed with the question; will the consequences of engaging in this behaviour make me feel good or bad?

• Normative beliefs refer to the ideas that are considered important by an individual's surroundings, such as family and friends. Motivation to comply refers to whether the individual also shares the same ideas or whether these are not relevant to the individual.

Theory of Reasoned Action Diagram

This diagram will help you understand the Theory of Reasoned Action and its components better:

Theory of Reasoned Action Example

The theory of reasoned action has been applied and researched in many health-related behaviours such as addictive behaviours (smoking, alcoholism, and gambling), breakfast and fast food consumption.

Hosseini et al. (2015) carried out a study to test whether the Theory of Reasoned Action would increase individuals' likelihood of consuming breakfast. The study included an intervention in which participants received an informational programme on breakfast consumption promotion.

Participants filled in a questionnaire about their attitudes towards breakfast consumption before and after the intervention. Results indicated that subjective norms were a strong predictor of behaviour. Participants were more likely to consume breakfast if they believed that those around them were consuming breakfast and that these people around them would want him/her to consume breakfast¹.

Theory of Reasoned Action Application

This theory has been used in a wide range of fields ranging from health behaviour, communication and consumer behaviour.

Evaluation of the Theory of Reasoned Action

The theory of reasoned action has been widely used in psychology. As with other theories, the theory of reasoned action presents both strengths and limitations. Here we will review both of them.

• The theory has been positively criticised for being a predictor of most human behaviour. The theory has been applied to a wide variety of fields such as exercise behaviour, and addictive behaviour. Despite this, the theory has received criticism.
  • Sheppard, Hartwick and Warshaw (1988) performed a meta-analysis in which they found that the TRA could accurately explain how humans make choices among options. On the other hand, the theory lacked the ability to explain how emotion affects human action. Further, other common behaviours such as habits were not explained by the theory.

• The theory of reasoned action has allowed many researchers to conduct research on it. It has been subject to assessment in numerous studies, and one of the main results found is that it can be applied across cultures.
  • Park (2009) was one of the researchers that evaluated the TRA. The results of his study suggested that social norms and social attitudes scores differ across cultures, depending on whether these are collectivist or individualistic.

Theory of Planned Behaviour Definition

The Theory of Planned Behaviour was developed in an attempt to improve the already existing Theory of Reasoned Action. Ajzen (1985) adapted the theory to include perceived behavioural control, which then became the theory of planned behaviour.

The adapted theory states that achieving a specific behaviour is not only dependent on one’s intention towards it, but also on whether a person believes they can do the behaviour.

This added component can further impact our behaviour in two ways:

1. If we believe we have greater control over our behaviour, we will form a stronger intention to engage in it.
2. If we believe we have greater control over our behaviour, then we will work longer and harder to succeed.

Perceived behavioural control thus can not only feed intention for a specific behaviour and impact it directly.