The paradoxical effects of religious fasting

Our project aims to explore how religious fasting, despite being associated with physical hunger and antisocial behaviour, can lead to positive outcomes such as happiness, wellbeing, and prosocial behaviour within a religious context.

The spiritual exercise of fasting exists in many different religious traditions. Yet physical hunger appears to be associated with some antisocial aspects of human nature – evidence suggests that hunger is associated with more interpersonal competition, manipulativeness, and anger and aggression. Why then would religious traditions recommend fasting as a spiritual discipline?

Understanding the effect of religious fasting

The commonness of fasting rituals across religions is a puzzle: whereas hunger is associated with a range of undesirable outcomes, including antisocial behaviour, religions are typically focused on fostering community and prosociality. Our projects aim to explore whether—and if so, how—hunger, when it occurs in a religious context, facilitates flourishing, including happiness, wellbeing, and prosocial behaviour.

Understanding the processes by which religions flip the effects of hunger from negative to positive will not only advance our understanding of human nature and the evolved psychology of hunger but could also lead to insights that (a) enhance religious practice by illuminating the ways through which fasting leads to flourishing, and (b) may suggest routes to enhance flourishing in a range of secular contexts.

Our approach and methods

Our project uses a wide variety of methods to examine the effects of religious fasting, as well as the mechanisms behind these effects. We have developed methods for social scientists to use Google search data, and we are using these data to examine whether societal well-being rises during fasting periods. We also conduct field experiments to test whether people are more likely to help strangers (for example, by posting an undelivered letter) during fasting periods. Finally, we will conduct experiments to test the relative effects of hunger and communal mindsets on both prosocial behaviour and wellbeing.

Understanding the effects of fasting on flourishing and the mechanisms through which fasting achieves these effects will address key challenges faced by faith communities. This research promises to reinvigorate engagement with the practice of fasting and to facilitate more meaningful and personally transformative periods of fasting for religious adherents and beyond.