The Theory of Planned Behaviour
As part of my research, I decided to look at theoretical models that could be used as part of campaigning work to engage parents. One obvious contender is the Theory of Planned Behaviour.
The Theory of Planned Behaviour (TPB) was developed by Icek Azjen in 1981, as an extension to the Theory of Reasoned Action (TRA), which was also developed by Azjen, with Martin Fishbein in the 1970s. (Fishbein & Azjen, 1975; Azjen & Fishbein, 1980). The TRA developed from work looking at the affect of attitudes on behaviour, and the importance of intention to/to not enact a behaviour and consists of the constructs; Attitude (the feeling someone has towards something) and subjective norm (perceived or actual social pressure to perform a behaviour). Attitude is affected by behavioural beliefs (what someone personally believes that they should do in relation to the behaviour) and subjective norm is affected by (what an individual believes others think should be done in relation to the behaviour). The TPB includes the additional construct of perceived behavioural control (PBC) (an individual’s control over being able to perform the behaviour), which is influenced by control beliefs (what someone believes relating to them being able to perform the behaviour). PBC has been linked to other constructs, such as self-efficacy (found in The Social Cognitive Theory), where an individual feels that they have control over a behaviour and can actually carry it out because they believe that they have the skills to do so. Attitude, subjective norm and PBC all have a direct influence on intention, with PBC also having an influence on behaviour (as without control over the behaviour it is not possible to enact).
To help illustrate the TPB model I have created a diagram with some phrases highlighting how each construct works within the model.
This theory has been used by numerous academics to study cognitive behaviours, such as car use, exercise and condom use. In some cases additional constructs, such as habit, have been added to strengthen the model’s predictive power. For campaign purposes, this model is useful as it’s constructs cover a lot of areas that are relevant and influencers on intention to carry out a behaviour. One area it is not as strong at, is considering affective influences, such as emotional feelings towards a behaviour. If a behaviour change (whether a campaign call to action or the actual behaviour itself) has significant emotional influence than there is a need to add constructs reflecting these into the model.