H Habilitation ▶ Rehabilitation Habit Strength Sheina Orbell Department of Psychology, University of Essex, Essex, UK Synonyms Habitual automaticity Definition A habit can be defined as a learned behavioral response to a situational cue. The repeated perfor- mance of a behavior in a specific context leads to the development of a behavioral habit that is trig- gered by features of the environment that have covaried frequently with past performance of the behavior. Such features of the environment might include performance locations, preceding actions in a sequence, the presence of particular people, or an internal thought or feeling. As a consequence of repetition in the same cue-contexts, a habit becomes capable of being triggered directly by perception of the cue. This is referred to as cue contingent automaticity. A person might experi- ence his or her habit as something “I cannot help doing.” Habit strength is a function of the frequency with which an action has been repeated in a stable context and has acquired a high degree of habitual automaticity. Verplanken and Orbell (2003) developed and validated a metacognitive 12-item instrument to measure habit strength, the Self- Report Habit Index (SRHI). This is a generic instrument that asks respondents whether their performance of a target behavior occurs fre- quently; requires conscious awareness, thought, and effort; and is difficult to control. From an empirical perspective, stronger habits are associated with heightened attention to cues associated with the performance of a habit and an increased likelihood of making an action slip when the cue is detected (Orbell and Verplanken 2010). Removal of the cue (e.g., by changing one’ s environment) disrupts the performance of a previous habit (Wood et al. 2005). Strong habits also disrupt the ability to enact a counterhabitual intention. Strong habits may be useful in health contexts where, for example, good adherence is © Springer Nature Switzerland AG 2020 M. D. Gellman (ed.), Encyclopedia of Behavioral Medicine, https://doi.org/10.1007/978-3-030-39903-0