title: When effects of the universal psychological need for autonomy on health behaviour extend to a large proportion of individuals: a field experiment.
abstract: OBJECTIVE
  Based on tenets of self-determination theory, the present manuscript examined the hypothesis that a physical activity intervention programme that supported the universal psychological need for autonomy would motivate a large proportion of young individuals to engage in physical activity. In contrast, we hypothesized that interventions that did not support the universal psychological need for autonomy would motivate a smaller proportion of young individuals to endorse the physical activity programme.
  
  
  METHODS
  A field experiment was conducted. Participants were randomly allocated to an intervention that supported the psychological need for autonomy and two conditions that did not support the psychological need for autonomy (rationale-only or forced-choice conditions).
  
  
  RESULTS
  It was demonstrated that more young individuals initiated and completed a physical activity intervention programme when the programme supported the psychological need for autonomy than when the programme did not support the psychological need for autonomy.
  
  
  CONCLUSIONS
  Results of the present study provide additional evidence to a growing body of literature recognizing the importance of universal psychological needs in motivating health-related behaviours.
authors.affiliation: Nan Yang Institute of Education, Singapore. nikos.chatzisarantis@nie.edu.sg
authors.forename: Nikos L D
authors.initials: NL
authors.lastname: Chatzisarantis
authors.forename: Martin S
authors.initials: MS
authors.lastname: Hagger
authors.forename: Sviatlana
authors.initials: S
authors.lastname: Kamarova
authors.forename: Masato
authors.initials: M
authors.lastname: Kawabata
mesh_terms: D000328:Adult; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D009042:Motivation; D026684:Personal Autonomy; D055815:Young Adult