Unlocking Behaviour Change

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

Unlocking Behaviour Change

Show Notes

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 Sign up to Robert’s Substack: https://robertwest100.substack.com/ Subscribe to the UBC YouTube channel: https://www.youtube.com/@unlockingbehaviourchange Ask a question at: https://www.unlockingbehaviourchange.com/contact-us

More from Unlocking Behaviour Change

Oct 20, 2026

Robert has been to China, and goes on about what an amazing time he had ...! In what’s left of the episode, Robert and Jamie give an overview of how to think about ‘active communication’ when it comes to changing behaviour.

Oct 13, 2026

In the previous episode, Robert castigated economics and economists' concept of 'utility' as fundamentally flawed, leading to models whose predictions keep being wrong. This week, Robert sketches out a way of thinking about utility that could improve economic modelling, yield more accurate predictions, and provide a more rational basis for macro-economic policy. A bold claim ... but this is a podcast, not an academic paper! 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 Sign up to Robert’s Substack: https://robertwest100.substack.com/ Subscribe to the UBC YouTube channel: https://www.youtube.com/@unlockingbehaviourchange Ask a question at: https://www.unlockingbehaviourchange.com

Oct 6, 2026

Robert has a bone to pick with economic theory . . . In fact, he wants to pick its bones clean and start over with a much better theory for everyone! Join the duo as they discuss what economic theory gets wrong and how it might be put right . . . 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 Sign up to Robert’s Substack: https://robertwest100.substack.com/ Subscribe to the UBC YouTube channel: https://www.youtube.com/@unlockingbehaviourchange Ask a question at: https://www.unlockingbehaviourchange.com

Sep 29, 2026

Derisory amounts of money paid for a piece of work called an 'honorarium' seem ok when if they were a 'fee', it would be insulting! Robert and Jamie discuss how we react differently to the same things when they are classified and labelled differently. This includes clinical diagnoses, where receiving a 'diagnosis' can be a huge relief to sufferers but can also carry stigma. 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 Sign up to Robert’s Substack: https://robertwest100.substack.com/ Subscribe to the UBC YouTube channel: https://www.youtube.com/@unlockingbehaviourchange Ask a question at: https://www.unlockingbehaviourchange.com

Sep 22, 2026

Robert and Jamie discuss the crucial question of how we classify and label things: one of the most basic things that we do in our mental and social world. But in an infinitely complex universe, putting things into boxes is fraught with difficulties, and classifications lie at the heart of important disputes. 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 Sign up to Robert’s Substack: https://robertwest100.substack.com/ Subscribe to the UBC YouTube channel: https://www.youtube.com/@unlockingbehaviourchange Ask a question at: https://www.unlockingbehaviourchange.com

See all episodes →