UC Merced

Objective: The theory of planned behavior is a prominent social cognition theory widely applied to predict physical activity. While prior meta-analyses of applications of the theory in this behavioral context have provided generalized support for its effects, limitations and evidence gaps have been noted such as syntheses of evidence on the unique effects of differentiated theory constructs, and effects of indirectly-measured belief-based constructs, on intentions and behavior. Further, there is a dearth of research on moderating conditions under which theory effects vary. To address these limitations and evidence gaps, we used synthesized data from a large-sample meta-analysis of applications of the theory in physical activity contexts to test effects of the basic theory and, importantly, particularly effects of differentiated and indirectly-measured theory constructs on physical activity intentions and behavior as well as examining effects of conceptually- and methodologically-salient moderators on theory effects including measurement correspondence and physical activity behavior types. Method: We identified studies reporting associations among measures of the attitude, subjective norm, and perceived behavioral control constructs, intentions, and behavior in a systematic literature search of theory applications in physical activity contexts. We tested theory effects and additional theory-implied effects in three models including versions adopting differentiated subcomponent constructs and directly- and indirectly-measured constructs, as well as effects of salient moderators, using optimal multilevel meta-analytic structural equation modeling techniques. Results: Model tests provided support for the theory- consistent patterns of effects for all three models including direct, and indirect intention mediated-effects, of core and differentiated constructs on physical activity behavior, and of the indirectly-measured constructs mediated by directly-measured counterparts. We also observed important theory-implied effects such as direct attitude-behavior effects. Moderator analyses revealed conceptually-salient differences in theory effects according to our moderators, particularly for measurement correspondence and behavior type. Conclusion: Beyond corroborating findings of prior meta-analyses of the theory, our analysis provides support for versions of the theory encompassing differentiated and indirectly-measured constructs, as well as moderators that represent key conditions that affect theory effects. Results provide support for key additional theory hypotheses not tested in previous research syntheses and set an agenda for future research applying the theory applications in physical activity contexts.