Sunday, October 17, 2004

Prayer of the heart

Last week the New York Times had a front page story on scientific tests of the efficacy of prayer. The gist of the story was that although much energy and money gone into testing the power of prayer, not much has come of it.

Prayer has two purposes: intersession and celebration. Only intercessory prayer expects a response that might be measured.

Sir Francis Galton, the nephew of Charles Darwin, was among the first to wonder if scientific methods might be used to test the efficacy of prayer. In an essay published in the Fortnightly Review in 1872, he compared the longevity of clergy as compared to doctors and lawyers. He found that clergymen as a whole did live slightly longer; however the longevity of eminent clergy compared to that of eminent doctors and lawyers was the shortest of all three groups.

Ockham's Razor would suggest that what Galton was really measuring was the stress of various lifestyles, rather than the power of prayer. He also examined the life spans of sovereign monarchs, for whom innumerable prayers for longevity are offered by faithful subjects. These much-prayed-for rulers of the realm were the shortest-lived of all groups considered by Galton.

Of course, none of this proves anything. Too many uncontrolled -- and uncontrollable -- variables render Galton's results inconclusive.

On the face of it, however, we can say with confidence that non-anecdotal evidence for the efficacy of prayer is conspicuously absent. Millions of Indians pray for sons rather than daughters -- the provision of prayers for the birth of sons is something of a major industry in India -- yet the sex ratio of Indian babies is the same as elsewhere in the world.

Yet it remains true that the great majority of humans swear by the power of prayer. This may indicate that skeptics fail to see what is obvious to everyone else. Or perhaps, as Galton wryly proposed, this could be evidence for a "universal tendency of man to gross incredulity."

In recent years, the scientific study of intercessory prayer has most often taken the form of double-blind experiments in a medical setting. Church congregations or prayer groups are asked to pray for some hospital patients. Other patients, the control group, are not prayed for. Neither the patients nor their caregivers know who is prayed for and who is not. Only after medical outcomes are determined are correlations sought.

Any such experiment is fraught with ambiguity. There is no way to control who is prayed for, by whom, or how much. And who is to say that God -- assuming he exists -- hears all prayers equally, or infallibly chooses to respond.

I have surveyed all the research done to date -- at least all that I can find -- and none has shown an unambiguous positive response. For example, a much ballyhooed study by Randolph Byrd on cardiac patients at San Francisco General Hospital did show small advantages in some aspects of treatment for prayed-for patients (less diuretics, fewer antibiotics), but mortality rates were the same as for the control group.

A more recent study at Columbia University that seemed to show a marginal efficacy for prayer has now been tainted with a charge of fraud.

Several other studies found no difference between prayed-for and unprayed-for patients.

Suffice it to say that for the time being no scientifically respectable evidence has been adduced for the efficacy of prayer.

Still, that won't stop people of faith from addressing petitions to God, and mistaking coincidence for answer. One half of Indian parents who have said prayers for a son will believe their prayers were answered; one half will wonder what fault of their own caused God not to listen.

None of this has any bearing on the other purpose of prayer: celebration. Regardless of one's theological beliefs or lack of them, it is difficult not to feel that the universe is shot through with mystery -- a profound interplay of law and chaos, beauty and terror that science can reveal in ever greater detail, but never fully understand.

I have seen no evidence for the efficacy of intercessory prayer, but I am as ready as the next person to hurl words of celebration into the dark and silent spaces between the galaxies.

Further Reading

I was not able to find online the following two studies on the efficacy of prayer, but here are the references:

C. R. B. Joyce and R. M. C. Welldon, "The Objecyive Efficacy of Prayer: A Double-blind Clincal Trial," Journal of Chronic Diseases, 18: 367-377 (1965). Joyce and Welldon found no effect, and wrote: "In the area of intercessory prayer, we see people confusing anecdotal evidence with scientific research. In fact, many people were very eager to tell us why they think that intercessory prayer is therapeutic, but were quite disappointed (and occasionally quite distressed) when we told them that we were looking for evidence from controlled scientific studies. Such confusion should alarm not only scientists, but anyone concerned about the health and safety of others."

Collipp, P. J., "The Efficacy of Prayer: A Triple-blind Study," Medical Times, 97: 201-204 (1988). Collipp concluded that prayer works, but the number of patients invloved was too small to be judged statistically significant.

Larry Dossey is a physician and best-selling guru of prayer: Healing Words: The Power of Prayer and the Practice of Medicine, Harper, San Francisco, 1993. Out of print.

If you read Dossey, or one of the many similar books, also check out Barry Beyerstein, "Why Bogus Therapies Seem To Work", Skeptical Inquirer, Sept.-Oct. 1997, pp. 29-34.

Herbert Benson at Harvard University has written on the topic: Timeless Healing: The Power and Biology of Belief, Scribner, New York, 1996. We await publication of Benson's extensive study of the therapeutic value of prayer.

Benson's book is notably reviewed by skeptics I. Tessman and J. Tessman in Nature, vol. 276, April 18, 1997, 369-370. Available online only by subscription.

Elizabeth Targ is often quoted as having amassed evidence for the effectiveness of healing prayer.

Student Activities

  1. What is Ockham's Razor?
  2. A test for the efficacy of prayer might be a good science project, if for no other reason than to discover how inclonclusive any such study must be and why it is NOT a good science project.

    Of course, you cannnot use human patients. You might see if prayer affects the growth of plants. Consider how many seedlings you need for a reliable study. How do you control for all variables except prayer? Make sure you do not know yourself which plants are being prayed for until after you have analyzed the results. And make sure you select people to pray who take their responsibility seriously. The prayer presumably should be that God makes himself manifest in the outcome of your experiment.

    Keep in mind the words of Reverend Raymond Lawrence Jr., director of pastoral care at New York-Presbyterian Hospital/Columbia University Medical Center: "There is no way to put God to the test, and that's exactly what you're doing when you design a study to see if God answers your prayers...This whole exercise cheapens religion, and promotes an infantile theology that God is out there ready to miraculously defy the laws of nature in answer to a prayer."

  3. If you decide that it is impossible to do a meaningful empirical test of intercessory prayer, you will know why scientists disqualify Creationism and Intelligent Design as science.

Discuss this essay and more over on the Science Musings Blog.