title: The impact of self-affirmation on health-behavior change: a meta-analysis.
abstract: OBJECTIVE
  Self-affirmation (induced by reflecting upon important values, attributes, or social relations) appears to reduce defensive resistance to health-risk information and increase subsequent readiness for health behavior change. However, these effects of self-affirmation have yet to be subjected to formal, quantitative integration. Consequently, the current article reports a meta-analysis of the impact of self-affirmation on outcomes at 3 key points in the process of health-behavior change: (a) message acceptance, (b) intentions to change, and (c) subsequent behavior.
  
  
  METHODS
  The literature search identified 144 experimental tests of the effects of manipulating self-affirmation on these outcomes. Effect sizes were extracted and meta-analyzed.
  
  
  RESULTS
  Across 34 tests of message acceptance (N = 3,433), 64 tests of intentions (N = 5,564), and 46 tests of behavior (N = 2,715), random effects models indicated small but reliable positive effects of self-affirmation on each outcome: acceptance, d+ = .17(CI = .03 to .31); intentions, d+ = .14 (CI = .05 to .23); behavior, d+ = .32 (CI = .19 to .44). Findings held across a range of health problems and behaviors.
  
  
  CONCLUSIONS
  The results suggest that deploying self-affirmation inductions alongside persuasive health information has positive effects, promoting message acceptance, intentions to change, and subsequent behavior. Though the effects are small in magnitude, they are comparable to those obtained in meta-analyses of other health-behavior change interventions. These findings are relevant to researchers and practitioners working to understand why people resist beneficial health information and how such resistance can be reduced.
authors.affiliation: Manchester Centre for Health Psychology.
authors.forename: Tracy
authors.initials: T
authors.lastname: Epton
authors.affiliation: School of Psychology, University of Sussex.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Harris
authors.affiliation: Department of Psychology, University of Sheffield.
authors.forename: Rachel
authors.initials: R
authors.lastname: Kane
authors.affiliation: Department of Communication Science, VU University Amsterdam.
authors.forename: Guido M
authors.initials: GM
authors.lastname: van Koningsbruggen
authors.affiliation: Department of Psychology, University of North Carolina at Chapel Hill.
authors.forename: Paschal
authors.initials: P
authors.lastname: Sheeran
mesh_terms: D000328:Adult; D005260:Female; D015438:Health Behavior; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D033182:Intention; D008297:Male; D010565:Persuasive Communication; D020377:Self Efficacy; D055815:Young Adult