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Category: Project

Description: Chvátalová et al. (2018) claim that cytomegalovirus infection impairs human intelligence, supported by the supposed existence of some specific false negative cases in the population, as well as a statistically significant correlation of certain intelligence scores and the level of cytomegalovirus antibodies in the blood. This paper aims to highlight several issues, both major and minor, we observed in their study. We consider mathematical errors, methodical issues and ethical concerns to be the major issues. The minor issues include ignored effect sizes, implicit hypotheses, and the absence of a theory that would explain the nature of the reported effects in detail. This commentary underwent extensive revisions since 2018, when its first draft was created, as well as a lengthy review process. The review started under the journal where the criticized article was published, and was subsequently transferred and completed under Meta-psychology. Even after more than three years since the publication of the criticized article, we are still convinced corrections should be made in order to prevent a potentially misleading interpretation and the unfavourable impact this study could have on both the experts and the public, especially when no errata have been published so far.