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September 21, 2010

The Claims:
Prayer is a religious ritual that has been practiced since ancient times. It is an act that seeks a connection to a god or spirit, and can take many different forms, in public or private, in words or song, in praise or in entreaty, and for personal benefit or for the sake of others.

The modern English word is derived from the 14th century French preiere, meaning “to obtain by entreaty.”

The Evidence:
Many religious people truly believe in the efficacy of prayer. Yet this can be explained by confirmation bias. An example: when someone prays for a specific result and that result later occurs, he believes that his prayer was “answered”. Most people fail to consider instances in which their prayer went “unanswered”? Statistically, one would expect some prayers to play out successfully by coincidence alone.

Ambrose Bierce offered a witty definition of the verb ‘to pray’: ‘to ask that the laws of the universe be annulled in behalf of a single petitioner, confessedly unworthy’.

Consider opposing armies on a battlefield, as both pray to god for victory over the other. The victor – and there is usually one – can always claim god was on their side.

Scientific studies regarding the use of prayer have mostly concentrated on its effect on the healing of sick or injured people (“faith healing”). The efficacy of prayer for healing has been evaluated in numerous studies, with inconclusive results.

In 1872, Francis Galton conducted a famous statistical experiment to determine whether prayer had a physical effect on the external environment. Galton hypothesized that if prayer was effective, members of the British Royal family would live longer, given that thousands prayed for their wellbeing every Sunday. He therefore compared longevity in the British Royal family with that of the general population, and found no difference. While the experiment was probably intended to satirize, it set the precedent for numerous subsequent studies.

Several 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 (unbeknown to them) assigned to a group that prayed for them and those who were not.

In a 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; interestingly enough however, the study found patients who had knowledge of receiving prayer had slightly higher instances of complications than those who did not know.

Many believe that prayer can aid in recovery not from divine intervention but simply due to psychological effect – knowing that one is being prayed for can be uplifting and morale-boosting, thus aiding recovery. This is no different from the placebo effect.

Finally, food for thought: Why has there never been one single documented instance of a person regrowing a limb through faith healing? Truly, that would be a “miracle”. There is a clever website which addresses this issue:

A final point to consider: Faith healing has been criticized on the grounds that those who use it may delay seeking potentially curative conventional medical care. This is particularly problematic when parents use faith healing techniques on children.

There is no evidence to support that prayer or faith healing works.

7 Comments leave one →
  1. fnord permalink
    January 22, 2014 8:36 PM

    This article does not mention research like “The Intention Project” and other research that has yielded positive results.

  2. Dave permalink
    January 19, 2012 4:56 AM

    This article has no basis in fact. A friend of mine went on a missionary trip to South Africa in 2008 and prayed for a man who’d lost his thumb in an industrial accident at work. His thumb spontaneously regenerated the next day. God DOES heal amputees.

  3. Andrew permalink
    March 5, 2011 10:09 PM

    @ Don.

    To call that SMJ article scientific proof is a fallacy of immense proportions. There was no researcher blinding and no control group in that study you cited, and the overall N is terrifically small. But I suspect it isn’t intended to be critically appraised, just merely foisted around as scientific proof of belief by Pentecostals (Which keeps the donations flowing for this sort of amateur research; as a feel good initiative for the people of Africa… where many cultures are deeply superstitious and still believe in magic). SMJ has an impact factor of less than 1, the acceptance of controversial articles is in their best interest to generate hype. I don’t see evidence of anything here.

  4. Brian Ritter permalink
    December 7, 2010 3:02 PM

    @Don –
    The study also found that more patients in the uninformed prayer group — 18 percent — suffered major complications, like heart attack or stroke, compared with 13 percent in the group that did not receive prayers. In their report, the researchers suggested that this finding might also be a result of chance. […]
    At least one earlier study found lower complication rates in patients who received intercessory prayers; others found no difference. A 1997 study at the University of New Mexico, involving 40 alcoholics in rehabilitation, found that the men and women who knew they were being prayed for actually fared worse.

    Patients who knowingly received prayers developed more post-surgery complications than did patients who unknowingly received prayers—and patients who were prayed for did no better than patients who weren’t prayed for. In fact, patients who received prayers without their knowledge ended up with more major complications than did patients who received no prayers at all.

    And finally:

  5. December 6, 2010 1:55 PM

    I prayed that all stupid people would become mutes but we still hear theme yapping Sunday mornings….

  6. Don permalink
    December 6, 2010 6:05 AM

    There actually has been positive results for the power of prayer recorded in peer-researched scientific studies. See

  7. December 3, 2010 7:38 PM

    beleivers claim all prayers are answered, but most of the time the answer is no.

    I think it’s telling how open a mind is.

    Playing word games to make the evidence or lack thereof proof of the claims is not open minded. It’s very closed because nothing is going to change it.

    Saying we don’t know or we don’t know yet – is an open mind because it’s a mind that is not yet made up.

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