title: Social structure, social cognition, and physical activity: a test of four models.
abstract: OBJECTIVE
  This study investigated the combined influence of social structural factors (e.g. income) and cognitions in predicting changes in physical activity. Four models were tested: (a) direct effects (social structural factors influence behaviour controlling for cognitions), (b) mediation (cognitions mediate social structural influence), (c) moderation (social structural factors moderate cognition-behaviour relations), and (d) mediated moderation (cognitions mediate the moderating effects of social structural position).
  
  
  METHODS
  Baseline and 3-month follow-up surveys.
  
  
  METHODS
  A random sample of 1,483 adults completed self-report measures of physical activity at baseline and 3-month follow-up. Measures of age, gender, education, income, material and social deprivation, intention, perceived behavioural control (PBC), and intention stability also were taken.
  
  
  RESULTS
  Apart from age, social structural factors exhibited very small or marginal effects on behaviour change, and only education moderated the intention-behaviour relation. In contrast, the magnitude of direct effects of the social cognition variables was comparatively large and intention stability mediated the moderating effect of education.
  
  
  CONCLUSIONS
  Stable intentions and PBC are the key predictors of changes in physical activity. Consequently, our findings would suggest the value of focusing on cognitions rather than social structural variables when modelling the determinants of physical activity.
authors.affiliation: Canada Research Chair on Behaviour and Health, Faculty of Nursing, Laval University, Quebec, Canada. gaston.godin@fsi.ulaval.ca
authors.forename: Gaston
authors.initials: G
authors.lastname: Godin
authors.forename: Paschal
authors.initials: P
authors.lastname: Sheeran
authors.forename: Mark
authors.initials: M
authors.lastname: Conner
authors.forename: Ariane
authors.initials: A
authors.lastname: Bélanger-Gravel
authors.forename: Maria Cecília B J
authors.initials: MC
authors.lastname: Gallani
authors.forename: Bertrand
authors.initials: B
authors.lastname: Nolin