When the one true faith trumps all: Low religious diversity, religious intolerance, and science denial.

Past theories have linked science denial to religiosity but have not explained its geographic variability. We hypothesize that it springs not only from religious intensity but also from religious intolerance, which depends greatly on the experience of religious diversity and hence on geography. The belief that one's religion trumps other faiths precipitates the stance that it trumps science too. This psychological process is most likely to operate in regions or countries with low religious heterogeneity. We measure the rejection of science not only in people's refusal to follow specific health recommendations, such as taking COVID-19 vaccines, but also in general measures of scientific engagement and attainment. We rule out alternative explanations, including reverse causality and spurious correlations, by conducting controlled experiments and running robustness checks on our statistical models.