Habit Formation and Behavior Change
Within psychology, the term habit is most often used to refer to a process whereby situations prompt action automatically, through activation of mental situation-action associations acquired through prior performances. Unlike consciously intended behavior, which proceeds via a cognitively effortful reflective processing system, behavior that is directed by habit is regulated by an impulsive processing system, and so can be elicited with minimal cognitive effort, awareness, control, or intention. The habit formation process involves a gradual transferral of action initiation from the conscious attentional or motivational processes involved in reflective processing, to external cuing mechanisms characteristic of impulsive processing. Behavior thus becomes detached from motivational or volitional control, freeing finite cognitive resources for unfamiliar or otherwise more demanding tasks. Upon encountering associated situations, habitual tendencies dominate action regulation, and alternative actions become less readily accessible.
By virtue of these characteristics, habit theory proposes that habit strength will predict the likelihood of enactment of habitual behavior, and that strong habitual tendencies will dominate over motivational tendencies. Evidence of these effects, albeit predominantly observational and correlational, has been found for many everyday socially significant and health-relevant behaviors, such as physical activity, healthy eating, alcohol consumption, TV viewing, and travel mode choice. Such findings have stimulated interest in habit formation as a behavior change mechanism—commentators have argued that adding habit formation components into behavior change interventions should sustain what are otherwise typically only short-term effects, by shielding new behaviors against potential motivational lapses. Habit-based interventions differ from non-habit-based interventions in that they include elements that promote context-dependent repetition, with the explicit aim of developing situation-action associations, and thus, situationally cued automatic behavioral responses. A wealth of habit-based behavior change interventions have been studied in clinical trials and have mostly shown positive effects on behavior. However, due to the methodological limitations of these trials, the longevity of such effects, and the unique impact on behavior of habit-focused components are not yet known. As an intervention strategy, habit formation has been shown to be acceptable to intervention recipients, who report that, through repetition, behaviors gradually become routinized and “second nature.” Whether habit formation interventions truly offer a route to long-lasting behavior change, however, remains unclear.