Definition
The theory of planned behaviour states that individuals’ behaviours are determined by their intentions which in turn are influenced by attitudes, subjective norms and perception of control over behaviour (Contento, 2010). Intention refers to the extent to which someone is ready to engage in certain behaviour. It refers to the likelihood that someone will engage in certain behaviour.
Therefore, the theory of planned behaviour is based on the concept that people are likely to do something if they plan to do it than if they do not. This means that intention is a key determinant on whether a certain action will be carried out.
Therefore, people are certainly not likely to engage in a certain behaviour if they do not intend to. However, intention is influenced by attitudes, social norms and perceived behaviour control (Edberg, 2009).
Attitudes
Attitudes are developed from a series of beliefs and they determine the value placed on the outcome of a given behaviour (Shaw, Gorely & Corban, 2005). A person’s behaviour will be favourable if he or she perceives the outcome of certain behaviour to be positive, desirable, beneficial or advantageous. Conversely, unfavourable attitude refers to a case whereby, an individual perceives the outcome to be unpleasant.
Hence, he or she is less likely to engage in that behaviour. For example, if a person believes that taking a lot of water will make him healthier then he is more likely to drink a lot of water (Ajzen, 2005). However, if the same person believes that taking a lot of water will make him lose his or her body shape, which he or she values, then he is less likely to take more water (Armitage & Christian, 2004).
Subjective Norms
Apart from attitude intention is also influenced by subjective norms. Subjective norm refers to a social pressure to engage or not to engage in a certain behaviour and is determined by normative beliefs (Wilson & Kolander, 2010). Therefore, subjective norms refer to those behaviours that we perceive that the important people in our lives expect from us.
The important people are those that we esteem highly who are our family members, religious leaders, healthcare providers, or friends and peers. Therefore, the subjective norms are as a result of our perceptions of the behaviours these people expect from us, and our desire to comply with the perceived expectations (Arnold, 2010).
For instance, a first-time mother is likely to feed her child only on breast milk for a longer period if her mother and the doctors emphasize it to her. However, she is likely to breastfeed her child for a short period if these people are not concerned. (Hayden, 2009).
Perceived behaviour control
The intention to do something is determined by the extent to which he or she can control that behaviour. The theory of planned behaviour is based on volitional control of behaviour whereby a person is able to decide at will to engage or not to engage in certain behaviour. For instance, a person decides whether to take lunch or not at will (Fishbein, Ajzen & Hornik 2007).
However, there are times when an individual cannot control the behaviour although he or she has a high intention to engage in that behaviour. Therefore, a person is less likely to engage in a behaviour if he or she has less control over the behaviour. Conversely, the same person has a high likelihood in a certain behaviour if he or she perceives or actually has a high control over the behaviour (Glanz, Rimer & Viswanath, 2008).
List of references
Ajzen I. (2005). Attitudes, personality and behaviour. Berkshire: McGraw-Hill International.
Armitage, C. J. and Christian A. (2004). Planned behaviour: the relationship between human thought and action. New Brunswick, NJ: Transaction Publishers.
Arnold V. (2010). Advances in Accounting in Behavioural Research. Bingley: Emerald Group Publishing
Contento, I. R. (2010). Nutrition Education: Linking Research, Theory, and Practice. Sudbury, MA: Jones & Bartlett Learning.
Edberg, M. C. (2009). Essential readings in health behaviour: theory and practice. London: Jones & Bartlett Learning.
Fishbein M., Ajzen I. and Hornik R. (2007). Prediction and change of health behaviour: applying the reasoned action approach. Mahwah, NJ: Routledge.
Glanz K., Rimer, B. K. and Viswanath K. (2008). Health Behaviour and Health Education: Theory, Research, and Practice. John Wiley and Sons.
Hayden J. (2009). Introduction to health behaviour theory. Sudbury, MA: Jones & Bartlett Learning.
Shaw D., Gorely T. and Corban R. (2005). Instant notes in sport and exercise psychology. New York, NY: Garland Science.
Wilson R. and Kolander, C. A. (2010). Drug Abuse Prevention: A School and Community Partnership. Sudbury, MA: Jones & Bartlett Learning.