A woman lights an oil lamp to celebrate Deepavali, the Hindu festival of lights. On the night of the new moon in the Tamil month of Aippasi, Hindu families counter the dark by decorating their homes with kolams (geometric designs drawn with rice flour) and oil lamps, and setting off sparklers and fireworks. Performing such religious acts may help individuals build strong, trusting relationships with others (see article). Image courtesy Eleanor Power

Roughly 80 percent of people around the globe identify with some type of religion, and scientists have been seriously pursuing insight into the evolutionary benefit of religious belief and practice since the early part of this century. In a new paper published today in Nature Human Behaviour, Omidyar Fellow Eleanor Power writes that active religious participation may benefit practitioners by strengthening social bonds. 

While some anonymized, lab-based experiments have suggested that religious behavior may increase prosocial qualities like generosity and trustworthiness, few researchers have studied this question in the context of a real community. In her study, Power analyzes how the nature of peoples’ religious practice correlates with the structure of their social support networks in two villages in South India.

How people embody their religion in public can vary in difficulty and costliness. A single trip to attend a religious service doesn't require much effort or money, but regular visits require greater commitment. Sacrificial offerings may not be difficult, but they are expensive. Some activities, like making a long pilgrimage or piercing the body with hooks and spears, are both physically and financially demanding. 

Community members who invest more in religious activity are viewed as being more trustworthy and generous. Consequently, these people are often sought out by others who need support. While this can create a burden, it also helps to foster more mutually supportive relationships. “Providing support to others means that one is more able to draw on support oneself,” writes Power in the new paper. 

“These religious acts make a lot of sense when you look at the social benefit,” says Power. In the South Indian communities in this study, most residents are poor, don’t have access to bank accounts, and they rely on family and friends to help with farming, home-building, and other crucial tasks. “So if your religious practice influences the likelihood and strength of those relationships, you’ll be much better able to withstand the vagaries of life.”

Read the paper in Nature Human Behaviour (March 6, 2017)