Disentangling the relation between intentions, planning, and behaviour: A moderated mediation analysis

Abstract

Action planning is assumed to mediate between intentions and health behaviours.Moreover, intentions are assumed to moderate the planning-behaviour relation,because people with high intentions are more likely to enact their plans.The present studies extend these suppositions by integrating both assumptions toa novel and parsimonious model of moderated mediation: the mediation effectis hypothesised to be stronger in individuals who report higher intention levels.In two longitudinal studies on physical activity (N124) and interdentalhygiene (N209), intentions and action planning were assessed at baseline,and behaviour was measured four (Study 1), and respectively, three (Study 2)months later. The moderated mediation hypothesis was tested withcontinuously measured intentions using regression analyses with non-parametricbootstrapping. Results from both studies suggest that levels of intentionsmoderate the mediation process: The strength of the mediated effect increasedalong with levels of intentions. Planning mediates the intention-behaviourrelation, if individuals hold sufficient levels of intentions. Implications fortheory advancement and intervention development are discussed.