Theory of Planned Behaviour

Question 1

Theory of Planned Behaviour

Answer 1

• Ajzen came up with this theory, which attempts to explain how we can alter behaviours over which we have self-control
• a key concept of the TPB is intention, since intentions predict behaviour
• when appleid to addiction, the theory links intentions to giving up drugs with actual changes in a person’s behaviour
• three key influences on intention - personal attitudes, subjective norms and perceived behavioural control
• all 3 of these aspects combine together to influence our intention to quit

Question 2

Personal attitudes

Answer 2

• the sum of all of the addicted persons attitudes towards their addiction
• this amounts in whether they see their addiction positively or negatively
• they must think of the outcomes and consequences of their addiction to make an accurate decision about their opinion
• e.g. someone with a nicotine addiction may have positive attitudes - relaxing, pleasurable - but also have negative attitudes - bad for my health, makes me cough
• positive and negatives are weighed up to come to an ultimate conclusion

Question 3

Subjective norms

Answer 3

• the beliefs of an addicted individual about whether the people around them, e.g. family and friends, approve or disapprove of their addictive behaviour
• this idea of their opinions is based on what they believe to be norms
• the addict will think abut the behaviour of their loved ones, if they partake in the same behaviour or not
• they will also think about the attitudes of their loved ones, such as if they have expressed any opinions towards the addictive behaviour or substance
• if the addicted person concludes that most people around them disapprove of the addiction, this would make them less likely to continue or more likely to quit
• however, if they think that most people approve, they will be more likely to continue and less likely to try to stop
• the addicts acts upon what they think the people around them think about their addiction, rather than what they actually think, and their perception may be messed up by irrational thoughts and the effects of the drugs

Question 4

Perceived behavioural control

Answer 4

• this is how much control we think we have over our own behaviour
• the addict may see giving up as hard or easy, based on their perception of internal and external resources to help them
• according to the theory, there are two effects that perceived behavioural control can have
  1. it can influence our intentions to behave, with the more control an addict believes they have linking to a stronger intention to stop
  2. can influence behaviour directly, so the greater the addicts perceived control over their addiction, the more control they have over their ability to stop it

Question 5

(+) EVAL - research support

Answer 5

• Hagger et al. (2011) investigated the predictions of the TPB about alcohol-related behaviours
• they found that the 3 factors all predicted a person’s intent to limit their drinking to unit guidelines
• this influence was found to extend into the long-term as well, with the people sticking to the guidelines 3 months after reducing
• they also found that perceived behaviour control had a direct effect on behaviour
• this shows support for the theory, however, there were a number of criteria which needed to be filled for it to apply correctly
  1. the time between intention and behaviour was very short
  2. theory wasn’t able to predict all addiction-related behaviours
• wasn’t able to predict binge drinking, which shows that the TPBs success is dependent on the addiction studied

Question 6

(-) EVAL - doesn’t explain addiction behaviour

Answer 6

• can’t account for the intention-behaviour gap, which is a major weakness
• it isn’t able to explain how behaviour results from intentions
• Miller and Howell (2005) studied gambling addiction in young teens and found strong support for intention prediction
• however, the model wasn’t able to predict the occurrence of gambling behaviour
• this leads some psychologists to believe that the model isn’t one of behavioural change
• since the theory cannot predict behavioural change, it becomes difficult to create drug-related interventions, bridging the gap between intention and action

Question 7

(-) EVAL - short-term v. long-term

Answer 7

• McEachan et al. (2011) conducted a meta-analysis of 237 studies of health behaviour, some of which related to addiction, and their link with the theory of planned behaviour and intentions
• they found that there was a variation in the strength of the correlation due to the time between intentions and behaviour
• intention may be a good predictor for giving up an addiction, but only if the time between intention and behaviour is less than 5 weeks or so
• in the longer term, the theory is on much weaker ground in trying to predict drug-related behaviour
• this therefore means that the theory cannot be accepted as entirely valid, since evidence for it is so mixed