This raises the possibility that celibacy might develop naturally. We created a mathematical model of the evolution of celibacy in which we examined the effects of becoming a monk on a man’s evolutionary fitness as well as the evolutionary fitness of his siblings and other village members in order to learn more about the specifics of how this occurs. We modeled both the situation when a child’s parents decide to send him to a monastery, as appears to be the case in our field study, and the situation where a boy makes his own decision.
Because monks are unmarried, there are fewer men vying for the women’s hand in marriage in the community. But even while being a monk can be advantageous for all the males in the village, the monk’s choice does not improve his own genetic fitness. Celibacy shouldn’t change as a result. But if having a monk brother increases men’s riches and makes them more attractive to women, the situation changes. Since the monk is assisting his brethren in bearing more offspring while remaining childless, religious celibacy can now evolve through natural selection. However, if the decision to become a monk is left up to the child, it is likely to stay uncommon because it isn’t very advantageous from a personal standpoint.
In the model, we demonstrate that celibacy only becomes significantly more prevalent if the parents determine it should occur. Parents send one child to the monastery as long as it benefits the others since they all get fit via having children. The fact that boys were welcomed into the monastery at an early age and suffered shame if they subsequently abandoned their vocation implies that this was a cultural practice influenced by family values.
This approach could also provide light on how infanticide and other forms of parental favoritism have developed in different cultural situations. A similar approach might also help to explain why female celibates (nuns) are uncommon in patriarchal civilizations like Tibet but more prevalent in societies where women are more competitive with one another, such as in societies where they have more inheritance rights (such as in parts of Europe).
In order to comprehend why the prevalence of monks and nuns differs among religions and geographical regions, we are now conducting new studies. It is frequently argued that when individuals adapt to a new norm, the diffusion of new ideas—even illogical ones—can lead to the establishment of new institutions. However, it’s possible that people’s choices on reproduction and economics might also influence institutions.