Definition
Behavior change is the deliberate modification of action patterns — habits, routines, automatic responses — toward a goal a person or group has chosen. Psychology treats it as a process rather than an event: a sequence of internal shifts (intention, motivation, self-efficacy) coupled with environmental and social supports that together make the new behaviour stable. It is the operational target of much of applied psychology: health interventions, addiction treatment, behavioural economics, workplace safety, and education all converge on the same question — how do you actually get a person to do something different, and keep doing it?
Models include the Transtheoretical Model's stages of change (pre-contemplation, contemplation, preparation, action, maintenance), the COM-B model (Capability, Opportunity, Motivation behind Behaviour), and the more granular Behaviour Change Wheel that maps interventions to intervention functions.
Why it matters
How it works
Effective change requires three things to align. Capability is the person's physical and psychological ability to perform the behaviour — knowledge, skill, attention. Opportunity is the social and physical environment that allows it — time, tools, supportive norms. Motivation is the reflective and automatic drives that energise it. If any of the three is missing, the new behaviour fails. Telling a sedentary office worker to exercise more (motivation) without providing a place, time, or community (opportunity) is the classic incomplete intervention.
Change is also rarely linear. Relapse is part of the standard model, not a failure of it — most behaviour change involves cycling through stages multiple times before maintenance is achieved. Interventions therefore plan for relapse rather than treating it as the end of the attempt.