Psychological profiles of anti-vaccination argument endorsement.

The proliferation of anti-vaccination arguments online can threaten immunisation programmes, including those targeting COVID-19. To effectively refute misinformed views about vaccination, communicators need to go beyond providing correct information and debunking of misconceptions, and must consider the underlying motivations of people who hold contrarian views. Drawing on a taxonomy of anti-vaccination arguments that identified 11 "attitude roots"-i.e., psychological attributes-that motivate an individual's vaccine-hesitant attitude, we assessed whether these attitude roots were identifiable in argument endorsements and responses to psychological construct measures corresponding to the presumed attitude roots. In two UK samples (total n = 1250), we found that participants exhibited monological belief patterns in their highly correlated endorsements of anti-vaccination arguments drawn from different attitude roots, and that psychological constructs representing the attitude roots significantly predicted argument endorsement strength and vaccine hesitancy. We identified four different latent anti-vaccination profiles amongst our participants' responses. We conclude that endorsement of anti-vaccination arguments meaningfully dovetails with attitude roots clustering around anti-scientific beliefs and partisan ideologies, but that the balance between those attitudes differs considerably between people. Communicators must be aware of those individual differences.

A taxonomy of anti-vaccination arguments from a systematic literature review and text modelling.

The proliferation of anti-vaccination arguments is a threat to the success of many immunization programmes. Effective rebuttal of contrarian arguments requires an approach that goes beyond addressing flaws in the arguments, by also considering the attitude roots-that is, the underlying psychological attributes driving a person's belief-of opposition to vaccines. Here, through a pre-registered systematic literature review of 152 scientific articles and thematic analysis of anti-vaccination arguments, we developed a hierarchical taxonomy that relates common arguments and themes to 11 attitude roots that explain why an individual might express opposition to vaccination. We further validated our taxonomy on coronavirus disease 2019 anti-vaccination misinformation, through a combination of human coding and machine learning using natural language processing algorithms. Overall, the taxonomy serves as a theoretical framework to link expressed opposition of vaccines to their underlying psychological processes. This enables future work to develop targeted rebuttals and other interventions that address the underlying motives of anti-vaccination arguments.

Rationally irrational: When people do not correct their reasoning errors even if they could.

Why is it that sometimes people do not correct their reasoning errors? The dominating dual-process theories of reasoning detail how people (fail to) detect their reasoning errors but underspecify how people decide to correct these errors once they are detected. We have unpacked the motivational aspects of the correction process here, leveraging the research on cognitive control. Specifically, we argue that when people detect an error, they decide whether or not to correct it based on the overall expected value associated with the correction-combining perceived efficacy and the reward associated with the correction while considering the cost of effort. Using a modified two-response paradigm, participants solved cognitive reflection problems twice while we manipulated the factors defining the expected value associated with correction at the second stage. In five experiments (N = 5,908), we found that answer feedback and reward increased the probability of correction while cost decreased it, relative to the control groups. These cognitive control critical factors affected the decisions to correct reasoning errors (Experiments 2 and 3) and the corrective reasoning itself (Experiments 1, 4 and 5) across a range of problems, feedbacks, types of errors (reflective or intuitive), and cost and reward manipulations pre-tested and checked in five separate studies (N = 951). Thus, some people did not correct their epistemically irrational reasoning errors because they followed the instrumentally rational principle of the expected value maximization: They were rationally irrational. (PsycInfo Database Record (c) 2023 APA, all rights reserved).