The stability of beliefs in conspiracy theories is comparable to or higher than some of the most stable psychological attributes

Williams, Matt N., Mathew Ling, John R. Kerr, Stephen R. Hill, Mathew Marques, Hollie Mawson, and Edward J. R. Clarke. 2022. “To What Extent Do Beliefs in Conspiracy Theories Change over Time?.” PsyArXiv. March 31. doi:10.31234/osf.io/5q2ky

Abstract: Recent years have seen an explosion in psychological research on beliefs in conspiracy theories. This research has produced a significant body of knowledge about the antecedents and consequences of inter-individual belief in conspiracy theories. What is less clear, however, is the extent to which individuals’ beliefs in conspiracy theories vary over time (i.e., intra-individual variation). In this descriptive and exploratory study we therefore aimed to describe intra-individual variability in belief in conspiracy theories. We collected data from 498 Australians and New Zealanders using an online longitudinal survey, with data collected at monthly intervals over six months (March to September 2021). Our measure of conspiracy theories included items describing ten unfounded conspiracy theories with responses on a 5-point Likert scale. While there was substantial variability in beliefs between different participants (i.e., inter-individual variability), there was much less intra-individual variability (intraclass r = 0.91). Indeed, it was common for participants to give exactly the same response to a given theory at every time point. Via power analyses, we demonstrate that the small quantity of intra-individual variation in beliefs in conspiracy theories has important consequences for sample size planning in longitudinal studies.