theory of planned behaviour Flashcards
Theory of planned behaviour
Model proposed by Ajzen (1985, 1991)
Cognitive theory about factors that lead to a person’s decision to engage in a particular behaviour
According to TPB, an individuals decision to engage in a particular behaviour can be directly predicted by their intention to engage in that behaviour
The theory suggests intentions arise from three key influences
Our personal attitudes
Our beliefs about what others think
Our beliefs about our ability to change our drug related behaviour
Personal attitudes
Refers to entire collection of addicts attitudes towards their addiction
Overall attitude is formed from weighing up balance of favourable and unfavourable attitudes
Subjective norms
Individuals beliefs about whether people who matter most to them approve or disapprove their behaviour
Ideas of normality are based on what key people in addicts life believe to be normal behaviour
If others are unhappy - less likely to intend to gamble
Most influential aspect of subjective norms is person’s perception of whether the people closest to them approve or disapprove of their behaviour
Perceived behavioural control
How much control we believe we have over our behaviour (self-efficacy)
This may be related to their perception of resources available to them, these can be external (money, time) and internal (ability, skill)
Has 2 possible effects:
- can influence behaviour directly: the greater the perceived control, the longer and harder the addict will try to stop
- can influence intentions to behave: the stronger the self-efficacy, the stronger the intention to stop
Strength
Supporting research evidence
Hagger et al 2011
Found TPB’s 3 factors predicted the intention to limit drinking - intentions were also found to influence actual alcohol consumption after one and three months . However, the theory was not able to predict behaviour related to all addictions (e.g. binge drinking)
Suggests although it can predict some addictive behaviours, its success may depend on the addiction being studied
Limit 1
Machine reductionist
Because TBP suggests individuals always make decisions rationally when deciding to partake in an addictive behaviour, unfairly ignoring irrational behaviours (e.g. emotions)
E.g. presence of strong emotions (e.g. frustration after argument) might explain why people fail to carry out an intended behaviour even when it is in their best interest to do so
This decreases validity of TBP as it unfairly oversimplifies the processes of behaviour change
Limit 2
Methodological issues with TPB
All components of the model are assessed using questionnaires which are influenced by social desirability bias
E.g. patients may express the intention to quit their addictive behaviours to the researcher as admitting they have no plan of quitting might be shameful and embarrassing
This suggests intentions expressed on questionnaires are poor predictors of actual behaviour, as people might lie
Limit 3
May not predict behaviour change
Armitage and Conner’s (2001)
Meta-analysis found that TBP was successful in predicting intention to change (e.g. I intend to stop smoking next week) rather than actual behavioural change (e.g. stopping smoking)
This weakens TBP as it cannot specify the processes involved in translating the intention into action
