On the origins of cultural differences in conformity: four tests of the pathogen prevalence hypothesis

What are the origins of cultural differences in conformity? The authors deduce the hypothesis that these cultural differences may reflect historical variability in the prevalence of disease-causing pathogens: Where pathogens were more prevalent, there were likely to emerge cultural norms promoting greater conformity. The authors conducted four tests of this hypothesis, using countries as units of analysis. Results support the pathogen prevalence hypothesis. Pathogen prevalence positively predicts cultural differences in effect sizes that emerge from behavioral conformity experiments (r=.49, n=17) and in the percentage of the population who prioritize obedience (r=.48, n=83). Pathogen prevalence also negatively predicted two indicators of tolerance for nonconformity: within-country dispositional variability (r=-.48, n=33) and the percentage of the population who are left-handed (r=-.73, n=20). Additional analyses address plausible alternative causal explanations. Discussion focuses on plausible underlying mechanisms (e.g., genetic, developmental, cognitive).