Le Petit Machiavellian Prince: Effects of Latent Toxoplasmosis on Political Beliefs and Values.

Humans infected by express no specific symptoms but manifest higher incidence of many diseases, disorders and differences in personality and behavior. The aim of this study was to compare the political beliefs and values of -infected and -free participants. We measured beliefs and values of 2315 responders via an online survey (477 -infected) using the Political Beliefs and Values Inventory (PI34). This study showed -infected and -free participants of our cross-sectional study differed in three of four factors of PI34, scoring higher in Tribalism and lower in Cultural liberalism and Anti-Authoritarianism. We found sex differences in political beliefs associated with infection. Infected women scored higher in tribalism and lower in cultural liberalism, compared with the -free control group, while infected men scored higher in economic equity. These results fit with sexual differences in behavior and attitude observed after toxoplasmosis infection. Controlling for the effect of worse physical health and mental health had little impact, suggesting that impaired health did not cause these changes. Rather than adaptation to prevalence of parasites, as suggested by parasite-stress theory, the differences might be side-effects of long-term mild inflammatory reaction. However, to get clear picture of the mild inflammation effects, more research focused on different infectious diseases is needed.