Measuring the effects of misinformation exposure and beliefs on behavioural intentions: a COVID-19 vaccination study

de Saint Laurent et al. Cognitive Research: Principles and Implications https://doi.org/10.1186/s41235-022-00437-y (2022) 7:87 Cognitive Research: Principles and Implications Open Access ORIGINAL ARTICLE Measuring the effects of misinformation exposure and beliefs on behavioural intentions: a COVID‑19 vaccination study Constance de Saint Laurent1, Gillian Murphy2, Karen Hegarty1 and Ciara M. Greene1*    Abstract Misinformation has been a pressing issue since the beginning of the COVID-19 pandemic, threatening our ability to effectively act on the crisis. Nevertheless, little is known about the actual effects of fake news on behavioural intentions. Does exposure to or belief in misinformation about COVID-19 vaccines affect people’s intentions to receive such a vaccine? This paper attempts to address this question via three preregistered experiments (N = 3463). In Study 1, participants (n = 1269) were exposed to fabricated pro- or anti-vaccine information or to neutral true information, and then asked about their intentions to get vaccinated. In Study 2, participants (n = 646) were exposed to true pro- and anti-vaccine information, while Study 3 (n = 1548) experimentally manipulated beliefs in novel misinformation about COVID-19 vaccines by increasing exposure to the information. The results of these three studies showed that exposure to false information about the vaccines had little effect on participants’ intentions to get vaccinated, even when multiple exposures led them to believe the headlines to be more accurate. An exploratory meta-analysis of studies 1 and 3, with a combined sample size of 2683, showed that exposure to false information both supporting and opposing COVID-19 vaccines actually increased vaccination intentions, though the effect size was very small. We conclude by cautioning researchers against equating exposure to misinformation or perceived accuracy of false news with actual behaviours. Keywords: Misinformation, Fake news, Vaccine, COVID-19 Significance statement The advent of the COVID-19 pandemic has drawn additional attention to the problem of online misinformation. This is particularly evident when we consider the potential consequences of misinformation for important health behaviours such as vaccination. It may therefore be surprising to learn that there is little evidence available about the direct effects of misinformation exposure on behaviour, as most research has focussed on belief in or willingness to share “fake news”. In this paper, we describe three experiments evaluating the effects of exposure to proand anti-vaccine information on participants’ intention to get a COVID vaccine. We report that a single exposure to a piece of true or false information about vaccination did not significantly affect participants’ willingness to get vaccinated. In Experiment 3, we report that showing participants the same piece of misinformation on multiple occasions increased their belief in the information, but still did not affect their behavioural intentions. Our results suggest that the relationship between exposure to, belief in and behavioural response to fake news is not straightforward. It is critical to understand when and how misinformation might affect individual or public behaviour, so that efforts to counteract it can be targeted where they are needed. *Correspondence: 1 School of Psychology, University College Dublin, Dublin, Ireland Full list of author information is available at the end of the article © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. de Saint Laurent et al. Cognitive Research: Principles and Implications Introduction While the COVID-19 pandemic has undeniably been accompanied by an impressive amount of misinformation—spreading faster and further than the disease itself (Depoux et al., 2020)—it is difficult to estimate the scale of the issue. There are, however, indirect signs: Between January and March 2020, for instance, the number of COVID-19 fact-checks available in English increased by 900% (Brennen et al., 2020). On Twitter, analyses of the URLs in COVID-related tweets have also shown that unreliable websites receive more attention than highquality health websites, although mainstream media retains the lion’s share (Singh et al., 2020). More worryingly, studies have shown that endorsement of misinformation is correlated with lower adherence to safety guidelines and reduced vaccination intentions (e.g. Earnshaw et al., 2020; ), as well as increased intentions to use unproven treatments (e.g. Bertin et al., 2020; Teovanović et al., 2021). In this context, it is often assumed that the relationships between exposure to misinformation, inaccurate beliefs and behaviour are causal. It makes intuitive sense that being exposed to fake news would make it more likely that an individual will believe the misinformation contained in it and act accordingly, but is it really that easy to convince people to refuse a vaccine or to take an unproven treatment like Ivermectin? Decades of research on persuasion, attitudes, and behaviour have demonstrated that persuasion is difficult, and the relationship between attitudes and behaviour is complicated at best (Crano & Prislin, 2006; Wood, 2000). Surprisingly, very few studies have looked at the effects of misinformation exposure on behaviours, beyond intentions to share information on social media. While sharing behaviours certainly contribute to the spread of fake news, it does not follow that such news is always taken literally or acted upon. People share misinformation for all kinds of reasons—from a desire to warn or educate others to signalling political ideology—and comments on false news shared on social media show that it is most often disbelieved (Metzger et al., 2021). To the best of our knowledge, only two studies have explored the consequences of fake news on real-world behaviours, both by looking at geographical patterns. Cantarella et al. (2019) used linguistic differences in South Tyrol in Italy to estimate how much misinformation the inhabitants of specific geographical areas were exposed to and whether it led to populist voting. They concluded that (...truncated)