Just Sitting? Social Cognition and the New Sedentary Psychology

Since 2000, considerable research attention has been directed toward understanding sedentary behaviour. Today, it is widely accepted that (1) sedentary behaviour is an independent predictor of morbidity and mortality, (2) the average Western adult engages in excessive amounts of sedentary behaviour, and (3) individuals should make efforts to reduce their sitting time. Considerably less work has examined the psychological aspects of the behaviour, such as motivation for sitting or how sedentary behaviour differs across context. Cognisant of these shortcomings, the purpose of the following dissertation was to explore two broad questions: first, does a psychological understanding of sedentary behaviour enrich our understanding of the behaviour as a whole?; second, which psychological factors play a role in predicting and/or changing sedentary behaviour? Three primary research studies were conducted. Study One aimed to develop a bottom-up understanding of how individuals define, understand, and experience sedentary behaviour. Participants completed a mixed-methods questionnaire that included items on, for instance, whether they perceived themselves as being high- or low-sedentary; or whether they wanted to change their level of sedentary behaviour. A prominent theme that emerged in this work was “rest and recovery”: that is, when asked to describe the benefits of their personal sedentary behaviour, the majority of participants noted mental and/or physical rest. Study Two examined how perceptions of sedentary behaviour are affected by activity type (television versus studying) and posture (sitting versus standing). Post-secondary students read four vignettes, with each vignette followed by questions on perceived self-efficacy, psychological outcome expectancies, and physical outcome expectancies. A series of secondary items examined preferences for sitting versus standing. Not only did participants express a clear preference for sitting, but a significant main effect was observed for posture and activity. The final study examined the utility of the Theory of Planned Behaviour (TPB) in prospectively predicting sedentary behaviour and standing breaks. Office workers completed four questionnaires across a period of two weeks, with items on attitudes, social norms, and perceived behavioural control; behavioural intentions; and self-reported behaviour. While results supported the basic tenets of the TPB, they also cast light on the complexity of sedentary behaviour: for instance, by highlighting psychological differences between work-time and break-time sitting. Collectively, the three studies indicate that the psychological basis of sedentary behaviour is neither simple nor necessarily intuitive, and that there is a need to engage in further psychological research before rushing toward intervention