Inoculating Against Anti-Vaccination Conspiracies

ABSTRACT

This study examined the efficacy of inoculation treatments in preventing anti-vaccination propaganda. Study predictions were tested in an independent-group experiment (N = 165), wherein participants were randomly assigned to a fact-based inoculation or a logic-based inoculation or a control message, with an excerpt from an anti-vaccination conspiracy film, Vaxxed, used as a counterattitudinal attack message. The results indicated that both inoculation treatments (fact-based and logic-based) were effective at instilling resistance to counter-persuasion, as compared to the control condition, and both types of inoculation messages were equal in their potential to facilitate resistance. In addition, we tested whether inoculating participants against an anti-vaccination conspiracy would help prevent the endorsement of other conspiracy theories. The data revealed that inoculating against one type of a conspiracy did not foster protection against other types of conspiratorial ideas, and, similar to previous research, endorsing one type of a conspiracy theory was positively associated with the endorsement of other conspiracies. These and other results are discussed along with their implications, limitations, and future research directions.

Disclosure statement

The authors do not have any conflict of interest influencing these results.

Supplementary data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10410236.2023.2235733.

Notes

1. The a priori power analysis indicated that we had sufficient power to detect medium global effects in MANOVA.

2. Forming indexes using principal axis factoring does not make a difference in these results. The examination of bivariate correlations between the variables formed based on principal component analysis vs. principal axis factoring revealed correlation coefficients above .97.

3. We also examined planned contrasts for the differences across conditions. The results of simple contrasts indicated that the difference between the control condition and fact-based inoculation treatment was significant: contrast estimate = .29, p = .05 (one-tailed). The difference between the control condition and logic-based inoculation treatment was not significant, p = .85.

4. Note that only 7% of participants indicated a strong endorsement for the anti-vaccination conspiracy. Excluding these 7% of participants from the analysis does not change the nature of these results. Unfortunately, the sample size for this portion of the study population was too small to examine therapeutic inoculation effects as argued in Compton (2020).

Additional information

Funding

Funding support for Elena Bessarabova was provided by the Dodge Family College of Arts and Sciences Senior Faculty Summer Fellowship.