2 Psychological Models of Health Behavior
Compare four psychological models of health behavior and learn how beliefs, confidence, social influences, and practical circumstances can shape action.
What shapes health behavior
Health behavior includes actions that affect health, such as vaccination, screening, exercise, medication use, and seeking care. Psychological models help explain why people choose these actions or do not, and can guide ways to support change.
The models focus on different influences, including beliefs about risk, motivation, confidence, habits, social influence, and practical circumstances. No single model explains every behavior, and these models describe influences rather than determine what any one person will do.
The
The (HBM) explains health action largely through beliefs about a health threat and the value and feasibility of responding to it. Its concepts help describe how someone weighs risk, possible benefits, expected difficulties, and their ability to act.
: How likely a person believes they are to experience a condition.
Perceived severity: How serious they believe the condition’s consequences would be.
Perceived benefits: Whether they believe an action will reduce the threat.
: Expected costs or difficulties, such as expense, side effects, inconvenience, or fear.
Cues to action: Prompts that encourage action, such as symptoms, a reminder, or a clinician’s recommendation.
Self-efficacy: Confidence in being able to take the action.
For example, someone may decide to get a screening test if they believe they could be at risk, consider the condition serious, trust that screening is useful, and feel able to arrange an appointment. A reminder may prompt action. If cost or transportation seems like an insurmountable barrier, awareness of risk alone may not be enough.
The
The (TPB) proposes that behavior is often preceded by an intention. Three factors shape that intention:
Attitude: Whether the person sees the behavior as beneficial or harmful, pleasant or unpleasant.
: Whether important people or groups seem to approve of or expect the behavior.
Perceived behavioral control: Whether the person believes they can carry out the behavior given their abilities and circumstances.
A person might intend to exercise because they expect health benefits, friends encourage it, and they believe they can fit it into their routine. However, intention does not guarantee action: a schedule change, unsafe walking route, or lack of childcare can interrupt follow-through. Perceived control can also relate directly to behavior, especially when it reflects actual control over obstacles.
(SCT) emphasizes interaction among personal factors, behavior, and the environment. These influences can affect one another over time, a relationship called . People learn through direct experience and by observing others.
Self-efficacy—confidence in one’s ability to act and persist despite difficulties—is especially important. Skills, expected outcomes, role models, and feedback can also shape behavior.
For example, someone learning to manage a chronic condition may gain confidence by practicing a task with a health professional, seeing a peer use the same skill, and receiving supportive feedback. Their success may then make it easier to continue and encourage others around them.
The
The offers a practical way to diagnose what may be preventing a behavior. It proposes that behavior depends on three interacting conditions:
Capability: Physical and psychological capacity, including health, knowledge, and skills.
Opportunity: External conditions that make the behavior possible or prompt it, including resources, time, access, and social support.
Motivation: Reflective decisions and goals as well as emotions, impulses, and habits.
Consider a patient who wants to take medication regularly. They may need clearer instructions to support capability, affordable access and a reliable pharmacy to support opportunity, or a reminder that helps establish a routine to support motivation. A useful response addresses the actual obstacle rather than assuming the patient simply lacks motivation.
Applying the models in context
The models highlight related but distinct influences. The foregrounds perceived threat, benefits, and barriers. The focuses on intention, social expectations, and perceived control. stresses learning, confidence, and interaction with the environment. COM-B checks whether capability, opportunity, and motivation are present.
These frameworks can organize questions about a health decision:
What does the person believe about the health risk and the recommended action?
What outcomes matter to them, and what makes the action worthwhile?
Do people important to them support or discourage it?
Do they have the skills, confidence, resources, time, and access needed?
Are stress, emotions, habits, or competing demands shaping the choice?
A person’s decision is situated in real life. Financial constraints, work schedules, family responsibilities, culture, past experiences, and access to respectful care can shape both beliefs and available options. Social support may provide encouragement and practical help, while stigma or unsupportive relationships may make change harder.
Health behavior should therefore not be understood as a simple measure of knowledge or willpower. Effective support matches strategies to the person’s beliefs and circumstances—for example, by clarifying benefits, addressing concerns, building skills, involving supportive others when appropriate, or reducing practical barriers.