Belief strength and the attitudinal and behavioural correlates of conspiracy beliefs

Even though conspiracy beliefs have been linked to behaviours such as vaccination and voting, the association is weak and heterogeneous. To shed light on this matter, we examined belief qualities associated with stronger correlations of beliefs with attitudes and behaviour. Across three studies-the first being pre-registered, two utilizing large, probability US samples and the last measuring behaviour prospectively-we analysed associations with prejudice (Study 1 N = 1959), vaccination behaviour (Study 2 N = 2572) and political behaviour (Study 3 N = 1551; total N = 6082). We found consistent evidence that conspiracy beliefs are linked to attitudes, and attitudes are related to behaviours. As hypothesized, this pathway is stronger when the beliefs are perceived as more certain or important, a tendency that is amplified when they are also perceived as more actionable. These findings have implications for addressing the most dangerous conspiracy beliefs and for understanding the belief-behaviour associations in other domains.