Zhu, Xuan2017-10-092017-10-092017-06https://hdl.handle.net/11299/190432University of Minnesota Ph.D. dissertation June 2017. Major: Mass Communication. Advisor: Marco Yzer. 1 computer file (PDF); iv, 321 pages.This dissertation tested whether people’s strength of self-esteem moderates self-affirmation effects on health message processing. The findings from three studies (Study 1: N = 115, Study 2: N = 294, Study 3: N = 426) with three different behavior contexts (sunscreen use, flossing, and alcohol consumption reduction) suggest that individuals’ strength of self-esteem can moderate self-affirmation effects on health message processing: people with high and low levels of self-esteem may respond differently to self-affirmation based health communication interventions in certain situations. However, despite the theoretical coherence, evident inconsistencies exist across the three studies. Therefore, at this point, a clear conclusion regarding when self-affirmation benefits people with high versus low levels of self-esteem cannot yet be reached and specific suggestions on how self-affirmation should be used in health communication practices cannot be provided. Nonetheless, this research has shown that individuals’ self-esteem levels can influence the effectiveness of self-affirmation-based health communication interventions, and sometimes not in a desirable direction. Interventionists therefore should use caution when incorporating self-affirmation elements in health communication interventions as it may have positive effects for some, but weak or even adverse effects among others.enDefensive processingHealth communicationMessage effectsSelf-affirmationSelf-esteemThesis or Dissertation