UC Merced

Background: Dispositional and trait-like constructs, particularly intra-personal personality traits and socio-political beliefs, have been consistently related to health behaviors, but the mechanisms have yet to be fully elucidated. The present study tested the extent to which effects of personality traits (conscientiousness and extroversion) and socio-political beliefs (political beliefs, locus of control, free will beliefs) on health behaviors are mediated by the theory of planned behavior constructs for three health behaviors: physical activity, COVID-19 vaccination, and sugar-sweetened beverage restriction. Methods: Proposed model effects were tested in a five-week prospective correlation study for three health behaviors. Finnish residents completed measures of constructs from the proposed model for physical activity (N = 557), COVID-19 vaccination (N = 1,115), and sugar-sweetened beverage restriction (N = 558) and self-reported their behavior at follow-up. Results: Single-indicator structural equation modeling revealed a non-zero direct effect of intention on behavior, and non-zero direct effects of social-cognition constructs on intention, across all behaviors. We also found non-zero indirect effects of political beliefs on behavior mediated by social cognition constructs and intentions for the COVID-19 vaccination and sugar-sweetened beverage restriction behaviors, non-zero indirect effects of conscientiousness on behavior mediated by social cognition constructs and intentions for the physical activity and sugar-sweetened beverage restriction behaviors, and non-zero indirect effects of health locus of control on behavior mediated by social cognition constructs and intentions for physical activity behavior. Further, there was a non-zero negative total effect of populist beliefs on behavior in the model for the COVID-19 vaccination behavior. Conclusion: The integrated model contributes to an evidence base of generalized intra-personal constructs and social cognition constructs of health behaviors and points to a possible mechanism by which the generalized constructs relate to health behavior.