---
title: "Efficacy of prayer"
chunk: 1/2
source: "https://en.wikipedia.org/wiki/Efficacy_of_prayer"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:31:18.538677+00:00"
instance: "kb-cron"
---

The efficacy of prayer has been studied since at least 1872, generally through experiments to determine whether prayer or intercessory prayer has a measurable effect on the health of the person for whom prayer is offered.
First-person studies suggest that praying can affect the person praying—sometimes improving physiological measures (like cardiovascular responses) and mental health, though results are mixed and often limited by self-report bias. Third-party studies on intercessory prayer (praying for others) have produced inconsistent results, with the largest and most rigorous trials generally finding no significant effect.
While some religious groups argue that the power of prayer is obvious, others question whether it is possible to measure its effect. Dr. Fred Rosner, an authority on Jewish medical ethics, has expressed doubt that prayer could ever be subject to empirical analysis. Basic philosophical questions bear upon the question of the efficacy of prayer – for example, whether statistical inference and falsifiability are sufficient to "prove" or to "disprove" anything, and whether the topic is even within the realm of science.
According to The Washington Post, "...prayer is the most common complement to mainstream medicine, far outpacing acupuncture, herbs, vitamins and other alternative remedies." In comparison to other fields that have been scientifically studied, carefully monitored studies of prayer are relatively few. The field remains tiny, with about $5 million spent worldwide on such research each year.

== Studies of intercessory prayer ==

=== First person studies ===

Studies can verify that those who pray are affected by the experience, including certain physiological outcomes. An example of a study on meditative prayer was the Bernardi study in the British Medical Journal in 2001. It reported that by praying the rosary or reciting yoga mantras at specific rates, baroreflex sensitivity increased significantly in cardiovascular patients.
A study published in 2008 used Eysenck's dimensional model of personality based on neuroticism and psychoticism to assess the mental health of high school students based on their self-reported frequency of prayer. For students both in Catholic and Protestant schools, higher levels of prayer were associated with better mental health as measured by lower psychoticism scores. However, among pupils attending Catholic schools, higher levels of prayer were also associated with higher neuroticism scores.

It has also been suggested that if a person knows that he or she is being prayed for it can be uplifting and increase morale, thus aiding recovery. (See Subject-expectancy effect.) Studies have suggested that prayer can reduce psychological stress, regardless of the god or gods a person prays to, a result that is consistent with a variety of hypotheses as to what may cause such an effect. According to a study by CentraState Healthcare System, "the psychological benefits of prayer may help reduce stress and anxiety, promote a more positive outlook, and strengthen the will to live." Other practices such as yoga, tai chi, and meditation may also have a positive impact on physical and psychological health.
A 2001 study by Meisenhelder and Chandler analyzed data obtained from 1,421 Presbyterian pastors surveyed by mail and found that their self-reported frequency of prayer was well-correlated with their self-perception of health and vitality. This research methodology has inherent problems with self-selection, selection bias, and residual confounding, and the authors admitted that the direction of perceived prayer and health relationships "remains inconclusive due to the limits of the correlational research design".

=== Third party studies ===
Various controlled studies have addressed the topic of the efficacy of prayer at least since Francis Galton in 1872, which spawned an entire series of commentary-debates that lasted for several years. Carefully monitored studies of prayer are relatively scarce with $5 million spent worldwide on such research each year. The largest study, from the 2006 STEP project, found no significant differences in patients recovering from heart surgery whether the patients were prayed for or not.
The third party studies reported either null results, correlated results, or contradictory results in which beneficiaries of prayer had worsened health outcomes. For instance, a meta-analysis of several studies related to distant intercessory healing published in the Annals of Internal Medicine in 2000 looked at 2774 patients in 23 studies, and found that 13 studies showed statistically significant positive results, 9 studies showed no effect, and 1 study showed a negative result.
A 2003 levels of evidence review found evidence for the hypothesis that "Being prayed for improves physical recovery from acute illness". It concluded that although "a number of studies" have tested this hypothesis, "only three have sufficient rigor for review here" (Byrd 1988, Harris et al. 1999, and Sicher et al. 1998). In all three, "the strongest findings were for the variables that were evaluated most subjectively", raising concerns about the possible inadvertent unmasking of the outcomes' assessors. Other meta-studies of the broader literature have been performed showing evidence only for no effect or a potentially small effect. For instance, a 2006 meta analysis on 14 studies concluded that there is "no discernible effect" while a 2007 systemic review of intercessory prayer reported inconclusive results, noting that 7 of 17 studies had "small, but significant, effect sizes" but the review noted that the three most methodologically rigorous studies failed to produce significant findings.

== Belief and skepticism ==