What’s Causing Secularization? Insecurity
Evolutionary modernization theory holds that both religiosity and pro-fertility norms are linked with existential insecurity, and a massive body of empirical evidence confirms this: secure people and secure countries show the lowest levels of religiosity. Existential security reflects not only a society’s per capita GDP but how evenly it is distributed, making income inequality a strong predictor of religiosity. Similarly, high levels of social welfare expenditures have a strong negative impact on religious attendance. Historic vulnerability to disease also has a persisting impact on religiosity: countries that were vulnerable to disease tend to be relatively poor and have low life expectancy and high infant mortality and high religiosity today. Overall, various indicators of existential security have a strong impact on religiosity, but this impact has a generational delay: the strongest predictor of religiosity around 2018 is the society’s level of infant mortality, not at the time of the survey but almost 40 years earlier, in 1980.