Theory of Reasoned Action

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.

What would be the example of the theory of reasoned action? And what would the the theory of planned behaviour be in comparison? Let's find out.

Theory of reasoned action: definition

In the theory of reasoned action, two main factors determine the intention to perform a behaviour:

1. Attitude refers to the judgement of whether or not a behaviour is good. Two behavioural beliefs further determine it: (a) beliefs about the outcome of the behaviour and (b) evaluation of the expected outcome.

   Someone may have an attitude that exercise is good for them. Keeping this in mind, the belief behind this could be ‘exercise can keep me healthy and help prevent ailments’, and the evaluation could be ‘I want to be healthy and not develop any medical problems’.

2. Subjective norms refer to the individual’s beliefs about their social world; if they think the people important to them (e.g., family, friends) want them to perform the behaviour. These norms further rely on the individual’s motivation to comply with these opinions (e.g., ‘do I want to do what they want me to do?’). To explain this further, let’s take this example:

The theory of reasoned action states that the above-mentioned factors (attitude and subjective norms) work together to produce intention, which ultimately leads to behaviour. Taking the same example of the theory of reasoned action as above, the individual’s beliefs generated the attitude that exercising is healthy, which is likely to create an intention for the individual to perform said behaviour.

On the other hand, if the same individual had negative beliefs about exercise such as, ‘exercise is inconvenient and I will probably injure myself’, ‘I don’t have time to exercise’, and ‘most of the people I know also don’t exercise’, then the intention will not be created, and therefore, the behaviour will not be performed.

While the basis of this theory is that intention precedes behaviour, other factors may intervene before the intention is realised. These are:

1. Time gap refers to the time gap between the expression of intention towards the behaviour and the actual behaviour; the bigger this gap is, the less likely it is for the intention to be expressed, as other influences and distractions can cause a change in attitudes and priorities.

   An individual may intend to exercise after work but might have a conversation with colleagues and end up going to the pub instead.

2. Specificity refers to how specific one’s intention is. If an individual has a general attitude that they should exercise, it is more likely this won’t translate into behaviour. Whereas, if the attitude is specific, i.e., signing up for a gym class at a specific time is likely to be a good basis for predicting the behaviour.

The theory of reasoned action diagram below will give you a better overview:

Theory of reasoned action diagram, Wikimedia Commons