[1][2] Wilson posits that religions are adaptive systems that have evolved to enhance their adherents' survival and reproductive success.
Wilson examines several case studies of religious traditions and communities, including Calvinism in Geneva, Balinese water temples, and the early Christian church.
Religious rituals and moral codes are seen as tools for maintaining social order and reducing conflict within groups.
Wilson suggests that understanding the adaptive functions of religion can inform policy-making and strategies for addressing social challenges.
The Journal of the American Academy of Religion called it "a welcome book because it unsettles everybody, evolutionary biologist and religious believer alike".