Social Norms and Reducing Belief in Conspiracy Theories

Conspiracy theories are explanations for important events that involve secret plots from powerful malevolent groups. Research finds that belief in conspiracy theories can lead to negative consequences for individuals and society. Importantly, belief in anti-vaccine conspiracy theories is related to vaccine hesitancy. Intervention attempts to attenuate the consequences of these beliefs thus far have had limited success. This thesis empirically tests social norms-based interventions to address anti-vaccine conspiracy beliefs.

Social norms are expectations about appropriate social behaviour. Our perceptions of social norms can exert a powerful influence on beliefs and behaviours. Across four studies, we found that perceived norms of in-group conspiracy beliefs are strongly related to personal conspiracy beliefs; demonstrated in a student sample (Study 1), in a community sample (Study 2), and specific to anti-vaccine conspiracy beliefs in a UK parent sample (Study 4). Similarly, the level of identification to the in-group is important in this relationship (Study 3). This thesis also found that individuals overestimated the perceived belief of others in conspiracy theories, misperceiving that these beliefs are more normative than they are.

Utilizing this knowledge, two experimental studies with UK parents were conducted, which paired anti-conspiracy counterarguments and social norm messages to address anti-vaccine conspiracy beliefs. However, these interventions were ineffective in reducing anti-vaccine conspiracy beliefs and increasing vaccination intentions (Studies 5 and 6). Combatting limitations of the previous interventions tested in this thesis, a Social Norms Approach (SNA) intervention was conducted, using normative feedback to challenge misperceptions of anti-vaccine conspiracy beliefs amongst UK parents (Study 7). The SNA intervention successfully reduced these beliefs, but the effects did not extend to increasing vaccination intentions.

Overall, the research in this thesis demonstrates the strong relationship between perceived norms of conspiracy beliefs and personal beliefs and the potential of the SNA to address these beliefs. Future research is invited to further explore the contribution of the SNA to reduce anti-vaccine conspiracy endorsement.