Religious celibacy is linked to marriage and wealth transmission practices across different world religions

Lifelong religious celibacy may seem to be an evolutionary puzzle. However, it is possible that where siblings compete for parental resources, families can benefit from having some offspring become celibate monks or nuns. Here, we test whether celibacy is more likely to be found in societies with substantial marriage transactions, lower levels of polygyny, and heritable wealth, especially land. Additionally, we predict male celibacy to be linked to polygyny and bride-wealth, and female celibacy to monogamy or polyandry and to dowry. Using Bayesian phylogenetic multilevel models on a cross-cultural sample of 352 societies, we find that celibacy occurs mainly in monogamous societies with heritable wealth, and male and female celibacy are more common where marriage payments are higher for the celibate sex. Buddhism and Christianity are especially likely to institutionalize celibacy, suggesting that the emergence of celibate religious institutions reflects common responses to similar socio-ecological conditions across cultures.