The COM-B Model for Behavior Change

The COM-B model for behavior change cites capability (C), opportunity (O), and motivation (M) as three key factors capable of changing behavior (B). Capability refers to an individual’s psychological and physical ability to participate in an activity. Opportunity refers to external factors that make a behavior possible. Lastly, motivation refers to the conscious and unconscious cognitive processes that direct and inspire change.⁵

Let’s look into each of these factors in a little bit more detail:

1. Capability
   Capability, in the context of COM-B, refers to whether we have the knowledge, skills, and abilities to engage in a behavior. This comprises psychological capability, including mental states, knowledge, and skills, as well as physical capability. For example, to make an individual feel capable of performing a behavior or achieving an outcome, implementing a training session to help support learning may boost feelings of capability.
2. Opportunity
   Opportunity, in the context of COM-B, refers to external factors that make the execution of a behavior possible. Physical opportunity, opportunities provided by the environment, and social opportunity are all valid components. For example, to create the opportunity to begin performing a behavior like new dietary patterns, free nutrition classes might help.
3. Motivation
   Motivation, in the context of COM-B, refers to the internal processes that influence decision-making and behavior. According to the model, two main components are reflective motivation (the reflective process involved in making plans) and automatic motivation (automatic processes such as impulses and inhibition). For example, to improve motivation, it may be helpful to turn a desired behavior from something one needs to do to something one wants to do, encouraging reflection on the benefits of performing that behavior.

An individual’s behavior will change if the above potential levers of change are successfully implemented. This model recognizes that behavior is influenced by many factors and that behavior change is induced by modifying at least one of these components.⁵ The COM-B model is particularly important when considering intervention methods, as interveners need to ensure the sustainability of learned behavior. To assist with its application, the COM-B is also often used in conjunction with the Behavior Change Wheel, which identifies categories of intervention that can be used to encourage behaviors in a target population.

Behavior change frameworks are the bedrock of applied behavioral science. Designed by behavioral scientists for policymakers and industry leaders, these summaries of cutting-edge decision-making insights are essential for applying research in the public and private spheres. Frameworks distill strategies for influencing human decisions into simple, portable mnemonic devices or acronyms. This makes it possible for complex, theoretical insights about how people think and act to make their way into the practices of organizations across every industry and physical environment. To understand more about how these frameworks work in practice, check out our case studies.

There are hundreds of frameworks out there, but COM-B tends to be used widely for a few reasons: a large body of literature shows that it works; it’s quite broad and therefore applies to many different contexts and industries; it links to a wider toolkit, called the Behavior Change Wheel, which essentially allows you to start with COM-B and reach very concrete and evidence-based intervention designs.

Behavior change interventions: Coordinated sets of activities designed to change specified behavior patterns. The patterns may be measured with respect to the incidence of behaviors in specified populations; for example, a behavior change intervention might target a particular high-smoking population to try to decrease daily cigarette intake.

Behavior Change Wheel (BCW): A framework designed to aid intervention designers in moving from a behavioral analysis of a problem to an evidence-based intervention method. This framework allows designers to identify intervention functions and policy categories that can bring about change.

Intervention functions: The broad categories of strategies used to bring about behavior change, as identified in the Behavior Change Wheel. These functions include education, persuasion, incentivization, coercion, training, restriction, environmental restructuring, and modeling. Each function targets different aspects of capability, opportunity, and motivation to effectively influence behavior.

Reflective motivation: The conscious processes that influence behavior, including planning, decision-making, and evaluating the consequences of actions. In the COM-B model, reflective motivation plays a critical role in guiding deliberate behaviors, as individuals weigh the pros and cons before taking action.

Automatic motivation: The unconscious processes that drive behavior, such as habits, impulses, and emotional responses. This aspect of motivation operates without deliberate thought and often influences behaviors that are habitual or driven by immediate emotional responses.

Physical opportunity: The environmental factors that make a behavior possible. This includes the physical presence of resources, tools, or spaces needed to perform a behavior. For example, access to a gym or availability of healthy food options can create the physical opportunity for someone to engage in regular exercise or healthy eating.

Social opportunity: The influence of one’s social network, cultural norms, and interpersonal relationships on behavior. It includes the support, encouragement, or pressure from others that can either facilitate or hinder the adoption of a particular behavior.

The COM-B Model was developed by Susan Michie, Maartje van Stralen, and Robert West in 2011 as part of their work to create a more comprehensive framework for understanding and influencing behavior change.⁵ At the time, there were numerous behavior change models available, but many were either too narrow in scope or too complex to be practically applied in diverse settings. Recognizing the need for a model that could be both broad and flexible, Michie and her colleagues sought to address these limitations by synthesizing insights from existing frameworks into a more cohesive and usable tool.

The development of the COM-B model was driven by the team's involvement in public health research, where they encountered the challenges of designing effective interventions across varied contexts, from smoking cessation to physical activity promotion. The model was designed to be simple enough to be applied in everyday practice, while also being grounded in psychological theory to ensure its scientific rigor.

COM-B is part of the broader Behavior Change Wheel (BCW), which Michie, van Stralen, and West developed in 2014.⁴ The BCW was created in response to the recognition that simply understanding the factors influencing behavior—capability, opportunity, and motivation—was not enough; there was also a need for a systematic method to design interventions that could target these factors effectively. The Behavior Change Wheel integrates the COM-B model with a comprehensive taxonomy of intervention functions and policy categories, providing a structured approach to developing behavior change interventions.

Over the years, the COM-B model has been applied in numerous studies and interventions, from enhancing individual behaviors in clinical settings to even improving public health incomes. 

What’s the best behavior change framework?

It depends on what kind of behavior change you’re trying to achieve. That being said, many people consider COM-B and the Behavior Change Wheel (a broader toolkit for behavior change that revolves around COM-B) to be a fairly good starting point. These tools are intentionally designed to start broad and cover a lot of ground. As you explore the elements of COM-B in the context of your behavior change goals, you might find that you need a much more specific framework and then switch to that one. For example, if you’re trying to build an exercise app and identify “Automatic Motivation” to mitigate negative feelings toward running as the crux of your challenge, you might want to switch over to a behavior change framework that focuses on building strong habit loops.

What are some of the practical pitfalls when applying COM-B and other behavior change frameworks?

COM-B tends to be a good starting point for many behavior change challenges—but it’s often best used as a starting point. One pitfall that we see quite often is that people stick to COM-B for every single context, from start to finish. While COM-B is quite thorough, it often leads us to problems that require other tools as a solution. For example, while COM-B covers a lot of ground, it’s probably not the best tool for a problem that’s centered around social proof.

How can I adapt frameworks like COM-B for different cultural contexts?

While COM-B is based on a wide body of research spanning the globe, there is no guarantee that it is the best tool for a specific audience. That’s why, as with any research tool, you should be using it to develop hypotheses that you test empirically in the exact context you’re studying. COM-B itself can be treated this way, but one thing to watch out for is the use of the rest of the Behavior Change Wheel and the interventions it suggests—those can be helpful as idea generators, but limiting yourself to interventions it spits out (which might be based on research focused on a very different group of people from the one you’re approaching) could be counterproductive. 

How can COM-B be used in case management?

COM-B can be a game-changer in case management by helping professionals really get to the heart of what drives their clients’ behaviors. Let’s break this down. Does your client have the skills or knowledge they need to stick to their care plan? That’s capability. Then there’s opportunity—making sure they’ve got access to the right resources and support systems to make those changes happen. Meanwhile, motivation is all about tapping into what really inspires them to stay on track, whether it’s sticking with treatment or getting involved in community programs. By using COM-B, case managers can better connect with their clients and guide them toward lasting, positive changes.

Understanding factors that influence behavior is the key to behavior change. The COM-B model of behavior change proposes that to engage in a behavior (B), a person must have the physical and psychological capability (C) and opportunity (O) to exhibit the behavior, as well as the motivation (M) to demonstrate the behavior at that specific moment. This tool has since been widely adopted across various sectors, including healthcare, public policy, and organizational behavior, due to its versatility and evidence-based foundation. 

COM-B and healthcare

In healthcare, the COM-B model has proven to be a valuable tool for designing interventions that improve patient outcomes and encourage healthy behaviors. By addressing the three core components—capability, opportunity, and motivation—healthcare providers can develop more effective strategies for patient adherence to treatment plans, medication routines, and lifestyle changes. For example, COM-B has been used to increase vaccination rates, enhance the management of chronic conditions, and improve patient participation in preventive screenings.10,11 By systematically identifying and targeting the barriers to behavior change, COM-B enables healthcare professionals to create interventions that are tailored to the specific needs and circumstances of their patients, leading to better health outcomes and more sustainable behavior changes, such as physical exercise and dietary patterns.

COM-B and public policy

COM-B has also been widely applied in the field of public policy, where it helps policymakers design and implement interventions aimed at changing population-wide behaviors. Whether it's encouraging recycling, reducing smoking rates, or promoting physical activity, the COM-B model provides a framework for understanding the factors that influence behavior at a societal level. By addressing capability, policymakers can ensure that citizens have the knowledge and skills necessary to engage in desired behaviors. By improving opportunities, such as by providing access to public services or creating supportive environments, they can make it easier for people to act. Finally, by fostering motivation through public awareness campaigns or incentives, policymakers can inspire citizens to adopt and maintain beneficial behaviors. The versatility of COM-B in public policy has led to its adoption in numerous government initiatives aimed at improving public health, safety, and well-being.

COM-B and organizational behavior

In organizational behavior, the COM-B model is increasingly used to drive change within companies and institutions. Organizations often face challenges in encouraging employees to adopt new processes, embrace cultural shifts, or engage in continuous learning. By applying the COM-B framework, organizational leaders can identify the barriers to change and design targeted interventions that address these obstacles. For instance, enhancing capability might involve providing training programs to develop the necessary skills for new tasks. Improving opportunity could mean restructuring workflows or providing the tools and resources needed to support change. Lastly, fostering motivation might involve aligning organizational goals with personal values or creating incentive programs that reward desired behaviors. Through the application of COM-B, organizations can create environments that support change, leading to improved performance, employee satisfaction, and overall organizational effectiveness.

In her 2016 paper, Jane Ogden, a Professor of Health Psychology at the University of Surrey, critiques the use of the COM-B model and the Behavior Change Wheel, arguing that these frameworks might oversimplify the complexity of human behavior.⁶ To understand her perspective, it's essential to revisit the origins of these tools. Back in 2008, researchers sought to identify which techniques were most effective in driving behavioral change. Their efforts culminated in the creation of the Behavior Change Technique Taxonomy, a resource designed to evaluate the success of interventions and ensure that the most effective strategies were implemented. However, Ogden contends that in developing this taxonomy, the natural variability in human behavior and interactions was largely overlooked. Meanwhile, proponents of the taxonomy argue that standardizing behavior change methods is crucial for maximizing intervention effectiveness, which they believe should be the primary focus.⁶

Ogden, on the other hand, challenges this notion, expressing skepticism about the ability of standardized protocols to predict outcomes accurately, especially given the inherent variability in human behavior. She points out that when there's a misalignment between a person's beliefs and their actions, it creates a disconnect—not only within the individual but also between the individual and the health professional. Moreover, she highlights another layer of disconnect between the health professional's beliefs and the training they receive to deliver these interventions.⁶ Ogden argues that by striving to systematize behavior change science, we risk neglecting the valuable nuances of human variability, ultimately diminishing the effectiveness of interventions and hindering the progress of behavior change science.⁷

COM-B model and improving hearing-aid use

Despite an abundance of evidence that hearing-aid use can improve the quality of life, 30% of the hearing-impaired community chooses not to wear them.¹ Barker and colleagues (2016) examined whether the application of the COM-B method could develop an intervention for this discrepancy in their target population. They interviewed 10 audiologists about their feelings on each component of the COM-B model. The audiologists reported that they felt that physical capability was not an issue for them, and both physical and social opportunities were important in determining whether behavioral planning was likely to occur. They also reported that the motivation component played an important role in determining the likelihood of carrying out behavioral planning. Altogether, capability, opportunity, and motivation were considered to be important drivers in filling hearing-aid fitting appointments. Barker and colleagues therefore argue that the COM-B model can effectively be used in audiology intervention development and provide self-management support.

COM-B model and improving antibiotic usage 

Antibiotic resistance is a serious threat to global health and is estimated to cause 10 million deaths per year by 2050 if no effective intervention is implemented.³ Duan and colleagues (2020) note that antibiotic resistance is caused by inconsistent use of prescribed antibiotics, often due to poor adherence to physician advice, the sharing of unused antibiotics, or the use of antibiotics for self-medication purposes. Unfortunately, the understanding of consumer behavior regarding antibiotic usage is limited. Duan and colleagues aimed to examine consumer behavior patterns and develop strategies to improve antibiotic usage in China using the COM-B framework. They identified the COM-B attributes of antibiotic consumers—what capability, opportunity, and motivation looked like—by conducting interviews with 30 participants. Duan and colleagues then developed, tested, and validated a measurement to understand antibiotic consumer behaviors. This measurement tool will allow the researchers to categorize and identify hidden behavior patterns of consumers. Duan and colleagues argue that their tool eases the process of developing and applying targeted interventions. For example, a home medicine review program may be useful for consumers who have a tendency to stockpile medicines and self-medicate.³

COM-B model and the COVID-19 pandemic

According to a 2020 review article published by Weston and colleagues, behavioral science plays a critical role in mitigating the effects of infectious disease outbreaks such as the COVID-19 pandemic.¹¹ The World Health Organization (WHO) encourages adaptive behavior change in response to public health emergencies. This sentiment is echoed by Michie and colleagues (2020) who state that, “Human behavior will determine how quickly COVID-19 spreads and the mortality. Therefore, behavioral science must be at the heart of the public health response.”² Weston and colleagues note that the COM-B model has been proposed as a starting point for interventions that would reduce virus transmission. This idea is further supported by a 2020 paper published in Nature, wherein authors West and colleagues argue that changing behavior is critical to preventing the transmission of COVID-19.¹⁰

As we know, behaviors such as social distancing, isolation, wearing a mask, and frequent handwashing are all critical to preventing the spread of COVID-19. These measures have been implemented by governments across the globe, however, according to West and colleagues, there is an urgent need to create interventions that improve human adherence.

The authors employed the COM-B model to understand how capability, opportunity, and motivation affect adherence to COVID-19 guidelines. They also employed the related behavior change wheel to identify the categories of intervention that should be included in the behavior change strategy; education, persuasion, incentivization, coercion, enablement, training, restriction, environmental restructuring, and modeling. West and colleagues found that interventions should target behaviors such as isolation and social distancing measures, specifically. They conclude that behavioral science models and methods, such as the COM-B, can be used to develop and evaluate such interventions.¹⁰

Stages of Change: How to Motivate and Reinforce Desired Behaviors

If you are interested in learning more about changing human behavior, this article outlines the tool of motivation, as well as how behavior change occurs through a series of stages.

A Nudge a Day Keeps the Doctor Away

If you are interested in reading more about how behavioral science is applied in the medical world, this article outlines how automaticity in our actions may be responsible for sub-optimal health behaviors.

1. Barker, F., Atkins, L., & De Lusignan, S. (2016). Applying the COM-B behaviour model and behaviour change wheel to develop an intervention to improve hearing-aid use in adult auditory rehabilitation. International Journal of Audiology, 55(sup3), S90-S98. https://doi.org/10.3109/14992027.2015.1120894
2. Behavioural science must be at the heart of the public health response to COVID-19. (2020, February 28). The BMJ. https://blogs.bmj.com/bmj/2020/02/28/behavioural-science-must-be-at-the-heart-of-the-public-health-response-to-covid-19/
3.   Duan, Z., Liu, C., Han, M., Wang, D., Zhang, X., & Liu, C. (2020). Understanding consumer behavior patterns in antibiotic usage for upper respiratory tract infections: A study protocol based on the COM-B framework. Research in Social and Administrative Pharmacy, 17(5), 978-985. https://doi.org/10.1016/j.sapharm.2020.07.033
4.   Michie, S., Atkins, L., & West, R. (2014). The behaviour change wheel: A guide to designing interventions.
5.   Michie, S., Van Stralen, M. M., & West, R. (2011). The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implementation Science, 6(1).https://doi.org/10.1186/1748-5908-6-42
6.   Ogden, J. (2016). Celebrating variability and a call to limit systematisation: The example of the behaviour change technique taxonomy and the behaviour change wheel. Health Psychology Review, 10(3), 245-250. https://doi.org/10.1080/17437199.2016.1190291
7.   Peters, G. Y., & Kok, G. (2016). All models are wrong, but some are useful: A comment on Ogden (2016). Health Psychology Review, 10(3), 265-268. https://doi.org/10.1080/17437199.2016.1190658
8.   Social Change UK. (n.d.). A guide on the COM-B Model of Behaviour. https://social-change.co.uk/files/02.09.19_COM-B_and_changing_behaviour_.pdf
9.   West, R., & Michie, S. (2020, April 9). A brief introduction to the COM-B Model of behaviour and the PRIME Theory of motivation. https://www.qeios.com/read/WW04E6.2
10. West, R., Michie, S., Rubin, G. J., & Amlôt, R. (2020). Applying principles of behaviour change to reduce SARS-Cov-2 transmission. Nature Human Behaviour, 4(5), 451-459. https://doi.org/10.1038/s41562-020-0887-9
11. Weston, D., Ip, A., & Amlôt, R. (2020). Examining the application of behaviour change theories in the context of infectious disease outbreaks and emergency response: A review of reviews. BMC Public Health,20(1). https://doi.org/10.1186/s12889-020-09519-2