Theory of planned behaviour Flashcards
What is the theory of planned behaviour (TPB)?
Predicts changes in behaviour from our intention to change, which is the result of personal attitudes, subjective norms and perceived behavioural control
Who devised TPB?
Ajzen
What are the 3 features of TPB?
1) Personal attitudes
2) Subjective norms
3) Perceived behavioural control
What are personal attitudes?
- Combo of favourable and unfavourable opinions about the addiction
- Formed by self-evaluation of positive and negative consequences of addiction-related behaviour
- E.g: what good things come from me smoking?
What are subjective norms?
- Beliefs about whether those who matter most to them approve or disapprove of their behaviour
- Based on what they believe to be the norm
- Consider what family/peers would think if they knew about addiction
- E.g: do my parents approve of my gambling behaviours?
How can subjective norms be applied to real life?
- Addiction-related intentions/behaviours can be altered by changing subjective norms
- Campaigns (Talk to Frank) combat teens overestimating peer substance abuse, by revealing the true extent of substance abuse amongst peers
What is perceived behavioural control?
- How much control we believe we have over our behaviour (self-efficacy)
- Dependent on their perception of support/resources
- 2 effects: indirect influence via intentions and direct influence
- E.g: do I have the ability to quit drinking?
How can perceived behavioural norms be applied to real life?
- Increasing self-efficacy could help gamblers quit/avoid relapse as it encourages a positive outlook and increased confidence in their ability to abstain
- Awareness that quitting requires effort (willpower)
- Resources (e.g: social support) helps develop control
Strength-
I- Research support
D- Hagger et al gave 486 participants questionnaires about their alcohol-related behaviour. Found that personal attitudes, subjective norms and perceived behavioural control correlated significantly with the intention to limit drinking. Intentions predicted number of units consumed after 1 and 3 months
E- High validity, and supports role of intentions in TPB
Limitation-
I- Research support fails to predict some alcohol-related behaviours
D- Attitudes, norms, control and intentions did not correlate significantly with the number of binge-drinking sessions after 1 and 3 months. Appears TPB’s success depends on type of addiction-related behaviour
E- Limited predictive validity
Limitation-
I- Short term effects only
D- McEachan et al’s meta-analysis of 237 TPB tests in predicting health behaviours found strength of correlation between intention and behaviour varies according to length. Intention to stop can predict the behavioural change, but only if intervening time if less than 5 weeks
E- Intentions may not predict change, so limits usefulness of TPB
Limitation-
I- Cannot account for the intention-behaviour gap
D- Cannot explain how behaviours are caused by intentions. Miller and Howell studied gambling behaviour in underage teens, and found strong support for some aspects of TPB (attitudes, norms, control were related to intention to stop). Key element not supported- intention was not related to actual gambling behaviour
E- If theory cannot predict behavioural change, it cannot be used to help change behaviour
Evaluation extra-
I- Rational decision making
Strength- Claims addiction is the result of rational decisions. Subjective norms formed from rational thinking process about others’ views and behaviours. Make a cost-benefit analysis by weighing up balance of attitudes towards favourable/unfavourable opinions
Limitation- Many factors (stress, cognitive bias, emotion) make decision-making irrational. E.g: when stressed people do not think rationally. Judgements and decision making effected. Data from questionnaires which may not reflect rational thought
E- TPB is unlikely to explain outcomes, as addicts make real life decisions under pressure, so may act irrationally
