The effects of religiously ordained ritualistic fasting on individual human behavior

April 04, 2023 Research

During this first week of April 2023, adherents of the three major monotheistic global religions – Judaism, Christianity and Islam – are participating, the world over, in various forms of religiously-ordained communal fasting rituals.

Observing Jews are preparing for Passover (pesach). This is a seven (sometimes eight) day holy period during which they will abstain from eating leavened bread at all times while also coming together for a communal evening meal, the Passover seder, marked by specific rituals shared over food.

Practicing Christians, meanwhile, are observing Holy Week, the last week of Lent, during which they will continue to abstain from certain proscribed foods, reduce the number of meals ingested, and avoid culinary luxuries (such as meat and alcohol), as they have during the entire period of Lent. Lent is a solemn 40-day period in the Christian calendar, culminating in Good Friday this week.

Finally, Muslims are observing the second week of Ramadan, the holiest month in the Islamic calendar, during which they fast (ṣawm) from dawn to sunset, while honoring other rules and rituals of prayer, reflection, and abstinence, before breaking their fast in a joyful communal meal, the iftar, at sunset.

All three major monotheistic religions, thus, traditionally require adherents to fast or abstain from their usual dietary practices at approximately the same time of the year.

To honor this special first week of April, we are proud to present two separate research projects by IAST researchers, both of which probe the effects of religiously ordained ritualistic fasting on individual human behavior.

First: IAST research fellow Jordan Moon explores, in his recent grant, the positive effects of religiously-prescribed fasting on an adherent’s overall physical and mental well-being, as well as their generosity towards others, and general public sociability.

Jordan and his co-authors highlight what they term the “paradoxical effects” of religious fasting: forced hunger typically has undesirable effects on emotions and social behavior (e.g., people often become “hangry”). Yet, many of the world’s religions require periods of hunger, and these periods seem to be associated with positive effects on well-being and generosity. This grant, funded by the Templeton World Charity Foundation, will explore what it is about religious fasting that “flips” the typical effects of hunger.

Jordan will use this grant to work on a larger research program that aims to understand how religious rituals influence an individual’s psychology. He will also explore the extent to which the effects of religious rituals on human behavior are particular to religion itself, or might they be replicated through secular belief systems. To read more about Jordan’s project, see here: Moon, J. W., Cohen, A. B., Laurin, K., & MacKinnon, D. P. (2023). Is religion special? Perspectives on Psychological Science, 18(2), 340-357.

To find out more about Jordan, see here:

Meanwhile, a related paper by Daniel Chen (TSE & IAS, and senior researcher CNRS) and his co-authors Sultan Mehmood and Avner Seror, published recently in Nature Human Behavior, explores the effect of Raman fasting on judges decision-making behavior in India and Pakistan. They used this as a way to explore the larger question of the impact of religious rituals on human decision-making impulses and processes.

Daniel and his co-authors scrutinized criminal sentencing decisions made by some 10,000 Muslim judges from Pakistan and India over a 50-year period. They found, in data culled from roughly half a million cases, that during Ramadan, judges who were fasting tended to be more lenient in their judgments than at other times. Acquittal rates increased by at least 10%.

Despite fasting from dawn to sunset, however, the judges were being neither sloppy nor hasty, for Daniel and Sultan also found that, in the same period, there were fewer appeals and reversals of judicial decisions.

They found no evidence of increased antipathy towards non-Muslim litigants. Nor did they find that fasting during Ramadan reduced judges’ productivity.

Ramadan, thus, had a significant positive impact on judges’ decisions, making them more, not less, inclined to leniency, without any loss of productivity or impartiality.

Daniel and Sultan’s paper offers insight into the potential positive effects of communal religious rituals on the criminal justice system in particular, and on human behavior more generally.

To read their paper, see here

To read more about Daniel’s work, see here

Photo de Rumman Amin sur Unsplash