Validating Vaccines: Understanding the Rhetorical Dynamics of Expertise Amid a Manufactured Controversy

Abstract

This dissertation examined the rhetorical dynamics of expertise around a manufactured science-based controversy. Using the ongoing debate surrounding vaccine-induced autism as a case study, this work explored the persuasive means used by voices competing for recognition as experts on a contested issue with technical elements. This study focused most closely on two key figures within the autism--vaccine controversy discourse: Andrew Wakefield and Jenny McCarthy. This dissertation employed a textual-intertextual approach to rhetorically analyze key discursive moments in the evolution of this controversy while also examining reception among audiences to understand how experts influence decision making around uncertain issues. This analysis revealed that the clarity of expert language practices used in technical settings becomes obscured in public contexts. It also uncovered the rhetorical power of style and appeals to ethos as substitutes for credentials or specialized knowledge when addressing non-specialist audiences who rely on judgments of trustworthiness in determining which experts to believe and whose advice to follow. Examination of parental discourses regarding vaccines illustrated that vaccine decisions derive from complex risk assessments for gauging whether the risks posed by vaccines outweigh the risks of not vaccinating. While mothers explicitly deny believing in vaccine-induced autism, language choices and expressions reveal that an underlying sense of doubt about the issue remains. Framing vaccines as medical aids that help protect vulnerable children and localizing public health messages to highlight the risks for a particular community offer promise for addressing vaccine hesitant attitudes in meaningful ways. Additionally, moving beyond supplying more information to dialoging with parents about the risks involved creates opportunities for building trust between practitioners and patients and encouraging acceptance of expert advice. Ultimately this dissertation argued that while the debates surrounding manufactured, science-based controversies seem to center on whether or not people believe the science, such issues are actually about which experts people trust. Recognition of this should reframe rejection of expert communication not as a matter of audience ignorance but as a failure in persuasion and should shift discourse toward building ethos and communicating common ground.