Objective: Despite abundant observational and experimental tests, it is not yet clear whether enhancing autonomous motivation or perceived competence leads to health behavior change. We identified interventions that aimed to change these constructs and quantified the magnitude of changes in behavior observed when interventions generated increases in autonomous motivation, perceived competence, or both.
Method: Computerized searches and additional strategies identified 67 articles that yielded 135 effect sizes relevant to our research questions. Random effects meta-analyses were conducted via STATA.
Results: Interventions increased autonomous motivation and perceived competence in 31% and 38% of tests, respectively. Increasing autonomous motivation led to a medium change in health behaviors (d+ = .47, 95% CI [.44, .83]) and increasing perceived competence generated a small-to-medium change (d+ = .34, 95% CI [.22, .47]). Interventions that failed to generate significant improvements in autonomous motivation and perceived competence had much smaller effects on behavior change (d+ = .13 and .10, respectively). There was little evidence of synergistic effects. Changing both autonomous motivation and perceived competence (d+ = .42) did not lead to a larger effect on behavior compared with changing autonomous motivation on its own (d+ = .61), but had a larger effect compared with changing perceived competence on its own (d+ = .21).
Conclusion: The present review suggests that autonomous motivation and perceived competence are valid targets for interventions to promote health behavior change but also indicates that research is warranted to ensure that interventions more effectively engage these targets. (PsycInfo Database Record (c) 2021 APA, all rights reserved).