The theory of planned behavior (Ajzen, 1991) is a way for scientists to understand why people do certain things. It is an extension of Ajzen and Fishbein’s theory of reasoned action (1980). The theory says that if a person has a desire to do something, they are more likely to actually do it. This is called “intention”. The theory states that intention is made up of three things: your attitude about the behavior (how you feel about it), what you think other people will think about it (called “subjective norms”), and how much control you have over doing it. When people have realistic control over doing something, they are more likely to actually do it.
This theory has been helpful in understanding why people participate in physical activities like sports. A meta-analysis conducted by Hagger et al. (2002) found that people’s intentions and perceptions of control could predict if they would participate in physical activities or sports. Attitudes and control were also important for predicting if people would want to participate in physical activities. Subjective norms were not as important for predicting if people would participate in physical activities.
Some scientists have criticized the theory of planned behavior, saying that it doesn’t take into account all the reasons people do things. However, it is still one main theories in exercise behavior research because it does explain a substantial amount of why people chose to do physical activity (Chatzisarantis et al., 2016).
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Ajzen, I., & Fishbein, M. (1980). Understanding attitudes and predicting social behaviour. Englewood Cliffs, NJ: Prentice- Hall.
Chatzisarantis, N. L. D., Barkoukis, V., et al. (2016). Prioritising at the margins: Effects of marginally higher prioritisation strategies on leisure time physical activity. Journal of Sport and Exercise Psychology, 38, 355366.
Hagger, M. S., Chatzisarantis, N., & Biddle, S. J. H. (2002). A meta-analytic review of the theories of reasoned action and planned behavior in physical activity: Predictive validity and the contribution of additional variables. Journal of Sport & Exercise Psychology, 24, 332.
