Parasitic manipulation, or side-effects? The effects of past Toxoplasma and Borrelia infections on personality and cognitive performance of humans are not mediated by impaired health - Data set

Data set for the paper Bacteria <em>Borrelia burgdorferi</em> <em>s. l.</em>, and especially protozoan <em>Toxoplasma gondii</em>, are known to affect the behavior of their animal and human hosts. Both pathogens infect a large fraction of humans, and both survive in the host’s organism for a very long time. The resulting latent infections were considered asymptomatic from a clinical point of view. However, in the last decade, a growing number of studies has shown that this view may be wrong and that both infections can have many adverse effects on the health of patients. Therefore, the specific behavioral effects of the infections might be just side-effects of the general impairment of the health of patients. Here we tested this hypothesis on the cohort of 7,762 members of the internet population using a 2-hours survey consisting of a panel of questionnaires and performance tests. We confirmed that subjects infected with <em>Toxoplasma</em> had worse physical and mental health and those infected with <em>Borrelia</em> had worse physical health than the corresponding controls. Infected and noninfected subjects also differed in several personality traits (conscientiousness, pathogen disgust, injury disgust, Machiavellianism, narcissism, tribalism, anti-authoritarianism, intelligence, reaction time, and precision). Most of the behavioral effects associated with <em>Borrelia</em> infection were the same as those associated with <em>Toxoplasma </em>infection; however, some of them dramatically differed, e.g., the performance in the Stroop test. Path analyses and nonparametric partial Kendall correlation tests showed that these effects were not mediated by the impaired health of the infected individuals. The results therefore contradicted the predictions of the side-effects hypothesis. Keywords: toxoplasmosis; borreliosis; manipulation hypothesis; big five; dark triad; disgust; Stroop test; Meili test; memory; intelligence; political attitudes; side-effects hypothesis