Originally published 17 October 2004
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.
