How does COM-B compare to the Theory of Planned Behaviour? Part 1 - Understanding the TPB

The COM-B model of behaviour was put forward in 2011 as a comprehensive model of behaviour, capturing influences that lay within individuals (capability and motivation) as well as the outside world (opportunity). It has become popular, with some 17,000 citations to the original paper, but nothing like as popular as the Theory of Planned Behaviour, whose primary reference, published in 1991, currently has 186,000 citations! In 2025 alone, the COM-B paper was cited almost 3,000 times, but the TPB was cited almost 22,000 times! 

With that in mind, Robert thought it would be interesting to compare the two models. In the first part of this two-parter, Robert explains the origins of the TPB and covers its main strengths and limitations as well as how it has evolved over the years. In the next episode, he will describe how the COM-B model differs and what that means for using these models to develop behaviour-change interventions.

Want more? Check out our latest books:  

Energise: The Secrets Of Motivation: https://shorturl.at/bbA7y 

React: Harness Your Animal Brain: https://shorturl.at/yiFQ9  

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