The invisibility of sitting: mental representations of sedentary behaviour

Abstract

BACKGROUND: Sitting time is a health risk factor independent of physical activity. Sitting research has been based on self-report, which assumes people are aware of sitting. Drawing on action representation theories, this paper presents three studies addressing the hypothesis that sitting is mentally encoded not as action in its own right, but rather as a procedural subcomponent of more purposeful actions (e.g. reading, driving). METHOD: In three experimental studies, participants categorised actions performed by people in photographs. Photographs unambiguously portrayed at least one person engaged in an activity while either seated or standing (e.g. a lady reading while sitting by a fountain). We examined the frequency with which participants organised actions according to posture (i.e. sitting or standing; Study 1) versus other action elements that we hypothesised to be more purposeful (e.g. reading; Studies 2 and 3). FINDINGS: When describing actions (Study 1; N = 89), participants rarely cited posture (<39% of descriptions). In a sorting task (Study 2; N = 268), participants were less likely to pair photos according to posture than other action elements (χ2 = 174.09, p<.001). In a memory test (Study 3; N = 50), participants recalled posture less (62%) than other action elements (90%; p<.001). DISCUSSION: People tend not to represent sitting as ‘sitting’. Sitting time may be more accurately recalled indirectly, using measures of time in typically-seated activities, rather than direct reflections on sitting. Sitting reduction interventions should acknowledge that sitting is a nonconscious action predominantly incurred by more meaningful seated activities.