Biased assimilation and need for closure: examining the effects of mixed blogs on vaccine-related beliefs.

This study examines the effect of mixed online information, in the form of user-generated blogs, related to the HPV vaccine on perceived efficacy and safety of this vaccine. Guided by the theoretical frameworks of biased assimilation and need for closure, this research hypothesizes that exposure to mixed blogs about the HPV vaccine will lead to polarization of HPV vaccine-related beliefs among individuals with opposing prior opinions about vaccination and that the polarizing effects will be most pronounced among those high in need for closure. A controlled experiment (N = 338) found support for the hypotheses with regard to efficacy beliefs but not with regard to safety beliefs. Implications for health communication research and practice are discussed.