Efficacy of prayer

Determining the efficacy of prayer has been attempted in various studies since Francis Galton first addressed it in 1872. Some studies have demonstrated benefit, some have demonstrated harm, and some have found no benefit from prayer. Others suggest that the topic is outside the realm of science altogether. According to the Washington Post, "...prayer is the most common complement to mainstream medicine, far outpacing acupuncture, herbs, vitamins and other alternative remedies."

To date, scientific, religious and philosophical views on the efficacy of prayer do not agree, and much controversy still surrounds the subject. Medical studies have, at times, provided conflicting conclusions, and debate continues regarding the confounding variables in some studies. Religious groups have objected to the very measurement of the efficacy of prayer and believe that what the studies measure is mechanical rather than real prayer.

The philosophical controversy on this topic even involves the basic issues of statistical inference and falsifiability as to what it may mean to "prove" or "disprove" something, and the problem of demarcation, i.e., as to whether this topic is even within the realm of science at all. Following his systematic review of healing as a therapy for human disease, in 2000, Neil C. Abbot of the Department of Medicine, University of Dundee, wrote: "No firm conclusions about the efficacy or inefficacy of healing can be drawn."

It should, however, be noted that in comparison to other fields that have been scientifically studied, carefully monitored studies of prayer are relatively few. If and when more studies of prayer are done, the issue of prayer's efficacy may be further clarified.

Studies on the efficacy of prayer
A number of studies have been performed to scientifically measure the impact of prayer, often within a medical setting. The studies performed have used different structural methods and measured both hard data (such as blood pressure variations) and soft data such as anxiety levels and number of doctor visits. They have measured first person effects (where the beneficiary performs the prayer) second person effects (where someone with a personal connection to the beneficiary performs the prayer) and third party effects where a group of unknown people pray for the beneficiary.

What can be measured?
Almost all second and third party studies have focused on petition based prayers, while first person studies have measured meditative prayers as well. In general, the requested outcome for a prayer as petition may be either an event in the physical world, e.g. the recovery of a person from an ailment, or an event in the spiritual world, e.g. the repose of a soul via a prayer for the dead. There are, of course, also certain types of prayer whose efficacy can not (by definition) be measured in the physical world, e.g. Roman Catholic tradition includes specific prayers and devotions as acts of reparation which do not involve a petition for a living or deceased beneficiary, but aim to repair the sins of others, e.g. for the repair of the sin of blasphemy. All medical studies mentioned below relate to events in the physical world, typically in terms of human effects, rather than inanimate effects such as "prayer for rain".

Study parameters
In most cases, the parameters measured within the medical studies cited here have not been all encompassing from scientific or religious view points. In particular some of the mental elements such as reverence which are emphasized by religious figures such as popes and saints have not been measured in the studies cited here. The studies have also not measured whether meditation prior to prayer impacts the outcome.

The studies cited here have also generally not measured physical parameters such as "proximity to the nearest place of common worship", e.g. does a prayer by a Christian within a Church have more effect than outside the Church? Does it vary by the size of Church? Does the effect increase or decrease if the Christian prays inside a Buddhist Temple? What about a Buddhist praying in a Church? Do prayers during Christmas have more or less effect? And the distance between the beneficiary and the location of the prayer has not been clarified in the studies, e.g. does prayer for a person who is a continent away have the same effect if the person were inches away? Does the "skill level" of the person praying have an impact on the outcome as stipulated by Wisneski and Anderson in their book The Scientific Basis of Integrative Medicine?

Wisneski and Anderson also hypothesize that different individuals have varying " prayer aptitude levels", just as different people have varying levels of athletic ability, and that the effect of prayer is the combined effects of ability and training. Pope John Paul II echoed that sentiment when he said: "We have to learn to pray: as if were learning this art ever anew." And he opposed "mechanical prayer" and emphasized the need for self reflection before prayer. The familiarity of the person praying with the words and method of praying, and their distraction level before they start to pray is not measured as a parameter in some studies, e.g. some participants in the 2006 cardiac bypass study by Benson and Sherwood complained that the mechanical way they were told to pray as part of the experiment was unusual for them.

The reverence with which the prayer is recited has been emphasized by other religious writers such as St. Louis de Montfort in his book Secret of the Rosary. In section 41 of Secret of the Rosary he emphasized the “purity of intention” and stated that it is not the length of a prayer that matters, but the fervor, purity and respect with which it is said, e.g. a single properly said Hail Mary is worth many that are badly said. Sections 42 and 43 of Montfort's book are devoted to "Attention" and “Fighting Distractions”.

First person studies
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.

Many accept that prayer can aid in recovery, not due to divine influence but due to psychological and physical benefits. 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.) Many studies have suggested that prayer can reduce physical stress, regardless of the god or gods a person prays to, and this may be true for many worldly reasons. According to a study by Centra State Hospital, "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.

A 2008 study by Bhutkar, et al. considered only 78 subjects, but concluded that the regular practice of Surya Namaskar had a positive impact on cardio-respiratory health.

Second person studies
One condition that may affect the efficacy of intercessory prayer is whether the person praying has a connection to the person prayed for. A 2005 study published by The Journal of Alternative and Complementary Medicine alleges evidence that healers in a variety of modalities were able to remotely influence the MRI-measurable brain activity in partners who were physically and electrically isolated, though little effort has been made to corroborate this study's conclusions.

Third party studies
The oldest statistical analysis of the effects of third party prayer was performed in 1872 by Francis Galton, perhaps as a form of satire as well as an experiment. Galton hypothesized that if prayer was effective, members of the British Royal family would live longer, given that thousands prayed for their well-being every Sunday. He therefore compared longevity in the British Royal family with that of the general population, and found no difference. However, Galton’s experiment suffered from a number of confounding variables.

Some studies of prayer effectiveness have yielded null results. A 2001 double-blind study of the Mayo Clinic found no significant difference in the recovery rates between people who were (unbeknownst to them) assigned to a group that prayed for them and those who were not. Similarly, the MANTRA study conducted by Duke University found no differences in outcome of cardiac procedures as a result of prayer. In another similar study published in the American Heart Journal in 2006, Christian intercessory prayer when reading a scripted prayer was found to have no effect on the recovery of heart surgery patients; however, the study found patients who had knowledge of receiving prayer had slightly higher instances of complications than those who did not know if they were being prayed for or those who did not receive prayer.

A number of studies have claimed that patients who are being prayed for recover more quickly or more frequently. One such study, with a double-blind design and about 500 subjects per group, suggested that intercessory prayer by born again Christians had a statistically significant positive effect on a coronary care unit population. Another such study was reported by Harris et al.. Critics claim Byrd's 1988 study was not fully double-blinded, and that in the Harris study, patients actually had a longer hospital stay in the prayer group, if one discounts the patients in both groups who left before prayers began, although the Harris study did demonstrate the prayed for patients on average received lower course scores (indicating better recovery). One of the largest randomized, blind clinical trials was a remote retroactive intercessory prayer study conducted in Israel by Leibovici. This study used 3393 patient records from 1990-96, and blindly assigned some of these to an intercessory prayer group. The prayer group had shorter hospital stays and duration of fever.

Most studies above have not to date directly measured the belief level of the beneficiary, leaving a possible confounding variable for the experiments.

Medical skepticism
An article in the Medical Journal of Australia complained that "One common criticism of prayer research is that prayer has become a popular therapeutic method for which there is no known plausible mechanism."

Some medical professionals are skeptical of new claims by studies until they have been given the test of time, and further scrutiny. For instance, a 2001 study associated with Columbia University has been associated with controversy, following claims of success in the popular media.

Medical hopes
In the early 20th century, Florence Nightingale, a pioneer of modern nursing, was a believer in the effects of prayer. She wrote, "Often when people seem unconscious, a word of prayer reaches them".

Today, the fact that different medical studies have been at odds with each other has not stopped physicians from studying or recommending prayer. According to Larry Dossey M.D.: "In 1993, only three U.S. medical schools had courses devoted to exploring the role of religious practice and prayer in health; currently, nearly 80 medical schools have instituted such courses".

Different approaches to medicine
In his book Reinventing Medicine Larry Dossey claims that there will be three eras of medicine, the first dealing with physical medicine (where patients take pills), the second with mind-body medicine (where the body treats itself through psychosomatic methods) and the third with eternity medicine in which patients are affected from a distance via intercessory prayer. As evidence, the book refers mostly to the same third party studies mentioned above, but suggests that they will be further strengthened by future studies.

Skepticism on scope of prayer
In a debate/interview in Newsweek with Christian evangelical Rick Warren, atheist Sam Harris commented that most lay perceptions of the efficacy of prayer (personal impressions as opposed to empirical studies) were related to sampling error because "we know that humans have a terrible sense of probability." That is, humans are inclined to recognize the few confirmations of their beliefs while discounting or ignoring the significantly larger number of disconfirmations.

Harris also criticized existing empirical studies for limiting themselves to prayers for relatively unmiraculous events, like recovery from heart surgery. He suggested a simple experiment to settle the issue: "Get a billion Christians to pray for a single amputee. Get them to pray that God regrow that missing limb. This happens to salamanders every day, presumably without prayer; this is within the capacity of God. I find it interesting that people of faith only tend to pray for conditions that are self-limiting."

Within Christian teachings, the comment by Harris regarding what he called the self-limiting nature of prayer had been addressed years before by multiple authors. For instance, in the 19th century William Peabody discussed the efficacy of prayer in the face of what he called the immutability of the laws of nature. He said:

Night follows day, and day night. The seasons preserve their succession... We may not hope to suspend their operation by our prayers... And yet notwithstanding all of this, we hold in an undoubting faith the doctrine of the efficacy of our prayers, or to use the language of another, "of an influence from above as diversified and unceasing as are the requests from below".

Peabody then argued at length that prayers may have efficacy in a form that does not interfer with the arrangement of the laws of nature, and that God may respond in ways that are not anticipated, without changing the arrangement of nature. George Burnap echoed the same concept when he wrote:

God governs the universe by fixed and uniform laws, not only for the sake of order, but for human good... The fulfillment of every human desire would break up this order, and bring everything into disorder and confusion.

Prayers and miracles
The view expressed by Harris above regarding the "relatively unmiraculous" petitions used in prayers has been addressed in religious circles in the context of miraculous outcomes for prayer. There are different theological classifications of miracles, one of the most common being the three categories: "surpassing nature" (Latin supra naturam), "against nature" (Latin contra naturam) and "alongside nature" (Latin praeter naturam).

The raising of the dead is considered a "supra naturam" event and is not reported in theological writings beyond the gospels. Contra naturam events require significant changes to the "order of the world" (e.g. regrowth of limbs) and are also hardly ever reported. Praeter naturam events can proceed along the laws of nature. They have been reported in a number of cases, and have been subject to a large amount of debate. Examples include the claims of miraculous cures at pilgrimage site such as Our Lady of Lourdes. Many of these claims have been analyzed and only a few have been accepted by the Lourdes Medical Bureau.

Massive prayer
The scientific measurement of the efficacy of massive prayer requires the coordination of the activities of a large number of people, and no direct citations for the existence of such studies appear in the scientific literature. However, non-scientific instructions for massive prayer have been issued in the past, and conclusions about the effects of the prayer have been drawn by a large number of believers, outside a scientific framework.

In a historical context, in 1571 Pope Pius V called for all of Europe to pray the Rosary for victory at the Battle of Lepanto, in which the Christian belligerents included the Papal States. Trophies from the battle are now enshrined in various Christian churches which attribute the victory to the massive prayers. For a scientific test, the battle would need to be repeated several times, in similar weather conditions, with each side refraining from prayer, or performing different types of prayers with varying degrees of effort over different time periods.

Directions for even more massive, long term prayers were provided by the messages of Our Lady of Fatima reported by Lucia Santos, who stated that the Virgin Mary specifically asked believers to pray for the conversion of Russia. The 9 day Fatima Novena prayer includes a petition for the conversion of Russia. With a blessing from Pope Pius XII (who called himself "the world chief against communism") millions of members of the Blue Army of Our Lady of Fatima were instructed to pray for several years in publications such as Soul Magazine. Some Christians attribute the fall of communism in the Revolutions of 1989 to massive prayers, while economists attribute them to market forces and socioeconomic conditions.

Religious and philosophical issues
Religious and philosophical objections to the very study of the efficacy of prayer exist, given that states, "You shall not test the Lord thy God", reflecting the notion of some that prayer cannot, or should not, be tested.

The religious viewpoint objects to the claim that prayer is susceptible to experimental designs or statistical analysis, and other assumptions in many experiments, e.g. that a thousand prayers are statistically different from one. The objections also include the complaint that religion generally deals with unique, uncontrollable events; statistics, and science in general, deal with recurring phenomena which are possible to sample or control and are susceptible to general laws.

Religious objections also include the complaint that as prayer starts to be measured, it is no longer real prayer once it gets involved in an experiment and that the concept of conducting prayer experiments reflects a misunderstanding of the purpose of prayer. The previously mentioned 2006 study published in the American Heart Journal indicated that some of the intercessors who took part in it complained about the scripted nature of the prayers that were imposed to them, saying that this is not the way they usually conduct prayer: "Prior to the start of this study, intercessors reported that they usually receive information about the patient’s age, gender and progress reports on their medical condition; converse with family members or the patient (not by fax from a third party); use individualized prayers of their own choosing; and pray for a variable time period based on patient or family request."

With respect to expectation of a response to prayer, William Payley wrote: To pray for particular favors is to dictate to Divine Wisdom, and savors of presumption; and to intercede for other individuals or for nations, is to presume that their happiness depends upon our choice, and that the prosperity of communities hangs upon our interest.

From a philosophical point of view, atheist philosopher Bertrand Russell believed that religion and science "have long been at war, claiming for themselves the same territory, ideas and allegiances". And Russel believed that the war had been decisively won by science. Almost 40 years earlier, a 22 year old Russell also wrote: ""For although I had long ceased to believe in the efficacy of prayer, I was so lonely and so in need of some supporter such as the Christian God, that I took to saying prayers again when I ceased to believe in their efficacy."

The 21st-century scientist Richard Dawkins on the other hand believes that some elements of religion are testable and has stated that "the alleged power of intercessory prayer is at least in principle within the reach of science".