Unpacking linguistic devices and discursive strategies in online social movement organizations: Evidence from anti-vaccine online communities

This study investigates linguistic devices and discursive strategies employed by online social movement organizations (SMOs) in attempts to deinstitutionalize long-standing, institutionalized behaviors. The research draws from an in-depth analysis of public discourse within anti-vaccine online communities in Italy and contributes to the social movement literature on framing and the theory of discursive institutionalization. It employs semi-automated text-analysis methods and interpretive analysis of textual data from seven anti-vaccine social media communities, before and subsequent to the 2017 regulatory intervention of the Italian government to increase vaccination rates. This intervention followed a phase of intense debate centered on the decrease in vaccination coverage and the spread of anti-vaccine ideas in social media as well as in the broader public discourse. The study analyzes the discursive strategies and linguistic devices of community leaders (moderators) and followers (members), and investigates shifts in micro-level online anti-vaccine discursive strategies that developed after the government regulation. The findings suggest that anti-vaccine online SMOs employ specific sets of linguistic devices, namely rhetorical fallacies, that support well-defined discursive strategies such as those aiming to delegitimize actors that endorse vaccines. Furthermore, the evidence shows that these linguistic devices and discursive strategies, after the government regulation, shift from an evidence-based stance towards values and emotions-based argumentations