Degree Type


Date of Award


Degree Name

Master of Science





First Advisor

L Alison Phillips


Many Americans are not meeting recommendations for engagement in health promoting and preventative behaviors. Multiple health behavior change (MHBC) interventions target at least two health behaviors to improve at least two health behaviors, and MHBC interventions may be both more economical and effective than single health behavior change (SHBC) interventions. However, the mechanisms through which MHBC (vs. SHBC) interventions may be more effective are unclear. Self-efficacy and identity are known predictors of behavior. The present study seeks to test a novel MHBC intervention and to simultaneously evaluate mediators of behavior change—namely self-efficacy for general health behavior engagement and development of a healthy-person identity. Specifically, participants engaged in one of three interventions: (1) MHBC intervention targeting fruit and vegetable consumption, and yoga practice; (2) SHBC intervention targeting fruit and vegetable consumption; (3) SHBC intervention targeting yoga practice; (4) No intervention control condition. ANOVA-based analyses test the hypotheses that individuals in the MHBC intervention condition will show the highest level in engagement in both target behaviors, compared to those in the SHBC intervention conditions and controls, and this effect will be mediated by differences in self-efficacy for and identity with engaging in health-related behavior. Lastly, Fisher's Z tests the theoretical hypothesis that changes in self-efficacy will precede changes in healthy identity. Mixed results were found, such that individuals in the MHBC intervention condition (vs. control condition) reported greater behavioral engagement in yoga but not fruit and vegetable consumption. The effect of experimental condition on target behaviors was not significantly mediated by general health self-efficacy or development of a general health identity. Finally, Fischer's Z test did not confirm a theoretical hypothesis that changes in self-efficacy will precede changes in healthy identity, but data appeared to be trending in the predicted direction. Overall, the MHBC intervention did effect greater behavioral engagement compared to the SHBC and control conditions. More research is needed to better understand the mechanisms through which behavior change occurs in the context of MHBC interventions.


Copyright Owner

Kathryn Bunda



File Format


File Size

102 pages