The research, an international collaboration among anthropologists and psychologists, looked at how religion affects humans' willingness to co-operate with those outside their social circle. The study involved interviews and behavioural experiments with nearly 600 people from communities in Vanuatu, Fiji, Brazil, Mauritius, Siberia and Tanzania whose religious beliefs included Buddhism, Christianity, Hinduism, animism and ancestor worship.

"Certain kinds of beliefs -- involving gods who are aware of human interactions and punish for moral transgressions -- can indeed contribute to the evolution of human co-operation," said lead author Benjamin Purzycki, a postdoctoral research fellow at UBC's Centre for Human Evolution, Cognition and Culture.

"If you think you're being watched, and expect to be divinely punished for being too greedy or thieving, you might be less inclined to engage in anti-social behavior towards a wider range of people who share those beliefs."

Results show that believers in all-knowing gods who punish for wrongdoing are more likely to behave fairly towards anonymous, distant "co-religionists" -- those who share beliefs about gods and rituals, but may not belong to the same religious organization.

When people act this way, the study suggests, they are engaging in behaviour that can support key features of modern-day societies -- such as large, co-operative institutions, trade, markets and partnerships.

"Religious beliefs may have been one of the major contributing factors in the development and stability of highly complex social organizations, such as states," said Purzycki.

Original paper : http://www.nature.com/nature/journal/vaop/ncurrent/full/nature16980.html