BACKGROUND: Little is known about how conspiracy beliefs and health responses are interrelated over time during the course of the coronavirus disease 2019 (Covid-19) pandemic. This longitudinal study tested two contrasting, but not mutually exclusive, hypotheses through cross-lagged modeling. First, based on the consequential nature of conspiracy beliefs, we hypothesize that conspiracy beliefs predict an increase in detrimental health responses over time. Second, as people may rationalize their behavior through conspiracy beliefs, we hypothesize that detrimental health responses predict increased conspiracy beliefs over time. METHODS: We measured conspiracy beliefs and several health-related responses (i.e. physical distancing, support for lockdown policy, and the perception of the coronavirus as dangerous) at three phases of the pandemic in the Netherlands (N = 4913): During the first lockdown (Wave 1: April 2020), after the first lockdown (Wave 2: June 2020), and during the second lockdown (Wave 3: December 2020). RESULTS: For physical distancing and perceived danger, the overall cross-lagged effects supported both hypotheses, although the standardized effects were larger for the effects of conspiracy beliefs on these health responses than vice versa. The within-person change results only supported an effect of conspiracy beliefs on these health responses, depending on the phase of the pandemic. Furthermore, an overall cross-lagged effect of conspiracy beliefs on reduced support for lockdown policy emerged from Wave 2 to 3. CONCLUSIONS: The results provide stronger support for the hypothesis that conspiracy beliefs predict health responses over time than for the hypothesis that health responses predict conspiracy beliefs over time.

Brain and Learning Research Group Learning and Innovation Center Avans University of Applied Sciences Breda the Netherlands

Department of Communication Science Radboud University Nijmegen Nijmegen the Netherlands

Department of Criminal Law and Criminology Maastricht University Maastricht the Netherlands

Department of Experimental and Applied Psychology Vrije Universiteit Amsterdam Amsterdam the Netherlands

Department of Political Science and Annenberg School for Communication University of Pennsylvania Philadelphia PA USA

Department of Psychology Education and Child Studies Erasmus University Rotterdam Rotterdam the Netherlands

Department of Psychology New York University New York NY USA

Department of Public Administration and Sociology Erasmus University Rotterdam Rotterdam the Netherlands

Department of Social Psychology University of Amsterdam Amsterdam the Netherlands

Departments of Political Science and Communication Science Vrije Universiteit Amsterdam Amsterdam the Netherlands

Kieskompas Amsterdam the Netherlands

Peace Research Center Prague Faculty of Social Sciences Charles University Prague Czechia

The Netherlands Institute for the Study of Crime and Law Enforcement Amsterdam the Netherlands

See more in PubMed

Bale, J. M. (2007). Political paranoia v. political realism: On distinguishing between bogus conspiracy theories and genuine conspiratorial politics. Patterns of Prejudice, 41(1), 45–60. doi:10.1080/00313220601118751. DOI

Bierwiaczonek, K., Gundersen, A. B., & Kunst, J. R. (2022). The role of conspiracy beliefs for COVID-19 health responses: A meta-analysis. Current Opinion in Psychology, 46, 101346. doi:10.1016/j.copsyc.2022.101346. PubMed DOI PMC

Bierwiaczonek, K., Kunst, J. R., & Pich, O. (2020). Belief in COVID-19 conspiracy theories reduces social distancing over time. Applied Psychology: Health and Well-Being, 12(4), 1270–1285. doi:10.1111/aphw.12223. PubMed DOI

Douglas, K. M., Uscinski, J. E., Sutton, R. M., Cichocka, A., Nefes, T., Ang, C. S., & Deravi, F. (2019). Understanding conspiracy theories. Advances in Political Psychology, 40(S1), 3–35. doi:10.1111/pops.12568. DOI

Enders, A. M., & Smallpage, S. M. (2019). Informational cues, partisan-motivated reasoning, and the manipulation of conspiracy beliefs. Political Communication, 36(1), 83–102. doi:10.1080/10584609.2018.1493006. DOI

Fazio, R. H., Ruisch, B. C., Moore, C. A., Granados Samayoa, J. A., Boggs, S. T., & Ladanyi, J. T. (2021). Social distancing decreases an individual's likelihood of contracting COVID-19. Proceedings of the National Academy of Sciences, 118(8), e2023131118. doi:10.1073/pnas.2023131118. PubMed DOI PMC

Festinger, F. (1957). A theory of cognitive dissonance. Stanford, CA: Stanford University Press.

Freeman, D., Waite, F., Rosebrock, L., Petit, A., Causier, C., East, A., … Lambe, S. (2022). Coronavirus conspiracy beliefs, mistrust, and compliance with government guidelines in England. Psychological Medicine, 52(2), 251–263. doi:10.1017/S0033291720001890. PubMed DOI PMC

Hamaker, E. L., Kuiper, R. M., & Grasman, R. P. P. P. (2015). A critique of the cross-lagged panel model. Psychological Methods, 20(1), 102–116. doi:10.1037/a0038889. PubMed DOI

Hornsey, M. J., Chapman, C. M., Alvarez, B., Bentley, S., Casara, B. G. S., Crimston, C. R., … Jetten, J. (2021). To what extent are conspiracy theorists concerned for self versus others? A COVID-19 test case. European Journal of Social Psychology, 51(2), 285–293. doi:10.1002/EJSP.2737. PubMed DOI PMC

Imhoff, R., & Lamberty, P. (2020). A bioweapon or a hoax? The link between distinct conspiracy beliefs about the coronavirus disease (COVID-19) outbreak and pandemic behavior. Social Psychological and Personality Science, 11(8), 1110–1118. doi:10.1177/1948550620934692. PubMed DOI PMC

Jolley, D., & Douglas, K. (2014a). The effects of anti-vaccine conspiracy theories on vaccination intentions. PLoS One, 9(2), e89177. doi:10.1371/journal.pone.0089177. PubMed DOI PMC

Jolley, D., & Douglas, K. (2014b). The social consequences of conspiracism: Exposure to conspiracy theories decreases intentions to engage in politics and to reduce one's carbon footprints. British Journal of Psychology, 105(1), 35–56. doi:10.1111/bjop.12018. PubMed DOI

Jolley, D., Douglas, K. M., Leite, A. C., & Schrader, T. (2019). Belief in conspiracy theories and intentions to engage in everyday crime. British Journal of Psychology, 58(3), 534–549. doi:10.1111/bjso.12311. PubMed DOI

Karic, T., & Mededovic, J. (2021). Covid-19 conspiracy theories and containment-related behavior: The role of political trust. Personality and Individual Differences, 175, 110697. doi:10.1016/j.paid.2021.110697. PubMed DOI PMC

Kenny, D. A., Kaniskan, B., & McCoach, D. B. (2015). The performance of RMSEA in models with small degrees of freedom. Sociological Methods & Research, 44(3), 486–507. doi:10.1177/0049124114543236. DOI

Krouwel, A., Etienne, T., & Kutiyski, Y. (2020). Kieskompas survey data: Public opinion in the time of COVID-19. Amsterdam: Kieskompas.

Lucas, R. E. (2022, February 14). It's time to abandon the cross-lagged panel model. PsyArXiv Preprint. doi:10.31234/osf.io/pkec7. DOI

Lüdtke, O., & Robitzsch, A. (2021, July 29). A critique of the random intercept cross-lagged panel model. PsyArXiv Preprint. doi:10.31234/osf.io/6f85c. DOI

Marinthe, G., Brown, G., Delouvée, S., & Jolley, D. (2020). Looking out for myself: Exploring the relationship between conspiracy mentality, perceived personal risk, and COVID-19 prevention measures. British Journal of Health Psychology, 25(4), 957–980. doi:10.1111/bjhp.12449. PubMed DOI PMC

Mercier, H. (2020). Not born yesterday: The science of who we trust and what we believe. Princeton, NJ: Princeton University Press.

Miller, J. M., Saunders, K. L., & Farhart, C. E. (2016). Conspiracy endorsement as motivated reasoning: The moderating roles of political knowledge and trust. American Journal of Political Science, 60(4), 824–844. doi:10.1111/ajps.12234. DOI

Mulder, J., & Hamaker, E. L. (2021). Three extensions of the random intercept cross-lagged panel model. Structural Equation Modeling: A Multidisciplinary Journal, 28(4), 638–648. doi:10.1080/10705511.2020.1784738. DOI

Mund, M., Johnson, M. D., & Nestler, S. (2021). Changes in size and interpretation of parameter estimates in within-person models in the presence of time-invariant and time-varying covariates. Frontiers in Psychology, 12, 666928. doi:10.3389/fpsyg.2021.666928. PubMed DOI PMC

Orth, U., Clark, D. A., Donnellan, M. B., & Robins, R. W. (2020). Testing prospective effects in longitudinal research: Comparing seven competing cross-lagged models. Journal of Personality and Social Psychology, 120(4), 1013–1034. doi:10.1037/pspp0000358. PubMed DOI PMC

Ployhart, R. E., & Ward, A.-K. (2011). The “quick start guide” for conducting and publishing longitudinal research. Journal of Business Psychology, 26(4), 413–422. doi:10.1007/s10869-011-9209-6. DOI

Pummerer, L., Böhm, R., Lilleholt, L., Winter, K., Zettler, I., & Sassenberg, K. (2022). Conspiracy theories and their societal effects during the COVID-19 pandemic. Social Psychological and Personality Science, 13(1), 49–59. doi:10.1177/19485506211000217. DOI

Rosseel, Y. (2012). Lavaan: An R package for structural equation modeling. Journal of Statistical Software, 48(2), 1–36. doi:10.18637/jss.v048.i02. DOI

Šrol, J., Mikušková, E. B., & Čavojová, V. (2021). When we are worried, what are we thinking? Anxiety, lack of control, and conspiracy beliefs amidst the COVID-19 pandemic. Applied Cognitive Psychology, 35(3), 720–729. doi:10.1002/acp.3798. PubMed DOI PMC

Van Bavel, J. J., Cichocka, A., Capraro, V., Sjåstad, H., Nezlek, J., Pavlović, T., … Boggio, P. (2022). National identity predicts public health support during a global pandemic. Nature Communications, 13, 517. doi:10.1038/s41467-021-27668-9. PubMed DOI PMC

Van Prooijen, J.-W. (2018). The psychology of conspiracy theories. Oxon, UK: Routledge.

Van Prooijen, J.-W. (2020). An existential threat model of conspiracy theories. European Psychologist, 25(1), 16–25. doi:10.1027/1016-9040/a000381. DOI

Van Prooijen, J.-W. (2022). Psychological benefits of believing conspiracy theories. Current Opinion in Psychology, 47, 101352. doi:10.1016/j.copsyc.2022.101352. PubMed DOI

Van Prooijen, J.-W., & Douglas, K. M. (2017). Conspiracy theories as part of history: The role of societal crisis situations. Memory Studies, 10(3), 323–333. doi:10.1177/1750698017701615. PubMed DOI PMC

Van Prooijen, J.-W., & Douglas, K. M. (2018). Belief in conspiracy theories: Basic principles of an emerging research domain. European Journal of Social Psychology, 48(7), 897–908. doi:10.1002/ejsp.2530. PubMed DOI PMC

Van Prooijen, J.-W., Etienne, T., Kutiyski, T., & Krouwel, A. P. M. (2021). Conspiracy beliefs prospectively predict health behavior and well-being during a pandemic. Psychological Medicine, 1–8. doi: 10.1017/S0033291721004438. PubMed DOI PMC

Van Prooijen, J.-W., Etienne, T., Kutiyski, T., & Krouwel, A. P. M. (2022). Just a flu? Self-perceived infection mediates the link between conspiracy beliefs and Covid-19 health beliefs and behaviors. Journal of Health Psychology, 27(6), 1421–1431. doi:10.1177/13591053211051816. PubMed DOI PMC

Van Prooijen, J.-W., Spadaro, G., & Wang, H. (2022). Suspicion of institutions: How distrust and conspiracy theories deteriorate social relationships. Current Opinion in Psychology, 43, 65–69. doi:10.1016/j.copsyc.2021.06.013. PubMed DOI

Van Prooijen, J.-W., & Van Vugt, M. (2018). Conspiracy theories: Evolved functions and psychological mechanisms. Perspectives on Psychological Science, 13(6), 770–788. doi:10.1177/1745691618774270. PubMed DOI PMC

Wang, Y. A., & Rhemtulla, M. (2021). Power analysis for parameter estimation in structural equation modeling: A discussion and tutorial. Advances in Methods and Practices in Psychological Science, 4(1), 1–17. doi:10.1177/2515245920918253. DOI