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Prayer Doesn’t Work . . . and it Might Even Kill You!

A new study on the healing power of prayer raises as many questions as it answers.
by Igal Moria & Ross Robertson

People have been praying on behalf of others—for the needy, for the health of a loved one—since at least biblical times. But does intercessory prayer actually work? Research in the late eighties and early nineties failed to produce conclusive results. Then in 1998, Dr. Herbert Benson of the Harvard Medical School, author of the 1975 bestseller The Relaxation Response and an icon in the field of mind-body research, designed the most ambitious prayer study ever conducted. Armed with a $2.4 million grant from the John Templeton Foundation, he began measuring the effects of intercessory prayer on the recovery patterns of eighteen hundred people undergoing cardiac bypass surgery in six U.S. hospitals.

The results of Benson’s landmark “Study of the Therapeutic Effects of Intercessory Prayer” (STEP), completed in 2001 and finally published last spring in the American Heart Journal, were met with a mixture of surprise and dismay by people whose faith or life experience has led them to believe in the healing power of prayer. Why? Because according to Benson’s research, intercessory prayer not only failed to reduce patients’ rates of postoperative complications, but for those patients who knew that they were being prayed for, it actually seems to have made things significantly worse.

That’s right—at first glance, Benson’s findings suggest that if you’re going in for heart surgery, having people pray for you may be a pretty bad idea. Participants in the study were randomly divided into three groups—two that didn’t know whether or not they would be prayed for (one did receive prayer and the other did not) and a third that knew for certain that prayers would be said for them. Complication rates for the first two groups were effectively equal—fifty-one percent for those who received no prayers and fifty-two percent for those who did. Fifty-nine percent of the third group, on the other hand, seem to have been adversely affected by the knowledge that divine aid was being sought on their behalf, and experienced complications during recovery.

Prayer doesnt work

What happened? For starters, some researchers have criticized the study’s design. Dr. Mitchell Krucoff, an eminent Duke University cardiologist and internationally regarded expert in alternative forms of healing, argues that the way the prayers were performed may have rendered them ineffective. Indeed, those who prayed for the patients knew nothing about them but their names, were instructed to stop praying after fourteen days, and were asked to modify their usual prayers to incorporate a short sentence written by the STEP designers. The authors of the study defended these measures as necessary for standardization, but renowned prayer for health protagonist Dr. Larry Dossey agrees with Krucoff, suggesting that because no one actually prays this way in “real life,” the constraints may have doomed the project from the start.

These concerns may or may not explain why prayer made no difference for those who weren’t sure whether or not they were receiving it, but what about those who did know and found themselves worse off for it? The STEP team has said only that this unexpected result “may have been a chance finding.” Krucoff, on the other hand, contends that approaching patients just prior to major surgery and informing them that prayers are to be said on their behalf is not exactly the best way to set their minds at ease. Dossey, who wrote a whole book about prayer’s potential for causing harm as well as good (Be Careful What You Pray For . . . You Just Might Get It), even goes so far as to suggest that the adverse results in the third group indicate some negative intention at play, be it cynicism on the part of the STEP investigators, strong antipathy from critics of prayer research, or even counter-prayers against the experiment by people who believe that putting prayer to the test is an act of heresy or blasphemy.

While counter-prayers might sound a little far-fetched, the medical efficacy of an intervention as subtle and mysterious as intercessory prayer is not an easy thing to reliably measure. And it’s not too much of a stretch to assume that, to some degree at least, researchers’ own attitudes are relevant to the success or failure of their research. Benson himself demonstrated this in a 1979 paper published in the New England Journal of Medicine, “Angina Pectoris and the Placebo Effect.” Apparently five different therapies for chest pain that were shown in an original study to be eighty percent effective were found to be completely ineffective in follow-up studies performed by different researchers. Later it was discovered that the authors of the first study enthusiastically believed the treatments would work, while the follow-ups were performed by physicians who had doubts. As Dossey comments, “The idea that an experimenter’s intentions might influence the outcome of the experiment is no more outrageous than the idea that someone’s prayers might change ‘the world out there.’”

So if, heaven forbid, you find yourself hospitalized and your doctor offers you intercessory prayer as part of your treatment, find outif he or she is a believer. And by all means, make sure that if prayers are said on your behalf, you don’t know anything about it. Because apparently the old adage is true: What you don’t know can’t kill you.


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This article is from
Our Mystery of Evolution Issue


January–March 2007


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