Scientific Studies of the Power of Prayer

A proposal was made in July of 1870 to set aside two wards in a London hospital and then have persons pray for those in one ward but not the other. As soon as word circulated about this experiment a cry of protest arose proclaiming that it was unethical to withhold treatment from those who needed it simply to test the efficacy of prayer.

In response to this outcry, the scientist and statistician Francis Galton wrote a paper in August 1872 for the Fortnightly Review: "Statistical Inquiries Into The Efficacy of Prayer," using the method of statistics on already available data.⁷ Galton was the grandson of Erasmus Darwin and a first cousin of Charles Darwin. Unfortunately, Galton became the father of the science of eugenics and his ideas of improving the human race were later incorporated into some of the worst atrocities of the Nazis in Germany.

With respect to prayer Galton wrote:

An eminent authority has recently published a challenge to test the efficacy of prayer by actual experiment. I have been induced, through reading this, to prepare the following memoir for publication, nearly the whole of which I wrote and laid by many years ago, after completing a large collection of data, which I had undertaken for the satisfaction of my own conscience. The efficacy of prayer seems to me a simple, as it is a perfectly appropriate and legitimate subject of scientific inquiry. Whether prayer is efficacious or not, in any given sense, is a matter of fact on which each man must form an opinion for himself. His decision will be based upon data more or less justly handled, according to his education and habits. An unscientific reasoner will be guided by a confused recollection of crude experience. A scientific reasoner will scrutinise each separate experience before he admits it as evidence, and will compare all the cases he has selected on a methodical system.

The question of prayer was said to be

a simple statistical question – are prayers answered, or are they not? There are two lines of research, by either of which we may pursue this inquiry. The one that promises the most trustworthy results is to examine large classes of cases, and to be guided by broad averages; the other, which I will not employ in these pages, is to deal with isolated instances. An author who made much use of the latter method might reasonably suspect his own judgment—he would certainly run the risk of being suspected by others—in choosing one-sided examples."⁸

Galton then chose the data he had acquired on longevity of various classes of people who had survived their thirtieth year, from 1758 to 1843. He excluded deaths by accident or violence. He found Members of Royal Houses had an average life span of 64.04 years, Clergy 69.49, Lawyers 68.14, Medical Professionals 67.31, the wealthy Gentry 70.22 and those in the fine arts 65.96. From these data he concluded: "The sovereigns are literally the shortest lived of all who have the advantage of affluence."⁹

Among the clergy, who regularly practiced prayers within their families and received prayers for them by their congregations, he concluded: "Hence the prayers of the clergy for protection against the perils and dangers of the night, for protection during the day, and for recovery from sickness, appear to be futile in result."¹⁰

Similarly, he pointed out that missionaries sent to foreign lands were prayed for intensely, but that their lives were notoriously cut short by illness and unfamiliar diets.

He also tested the efficacy of prayer by "inquiry into the proportion of deaths at the time of birth among the children of the praying and non-praying classes." He found: "However, the distribution of still-births appears wholly unaffected by piety."¹¹

His conclusion that God does not answer prayers caused a stir in England and much controversy about the use of scientific methodology to address matters of faith. As a result there were few published papers until Randolph C. Byrd, a cardiac physician in San Francisco published a startling paper in July 1988, in the Southern Medical Journal.¹²

In a carefully designed random double-blind protocol Byrd examined the effect on 393 patients admitted to a coronary care unit (CCU) who after signing informed consent were divided into two groups of 192 and 201 patients. "While hospitalized, the first group received intercessory prayer (IP) by Christians praying outside the hospital; the control group did not. At entry, chi-square and stepwise logistical analysis revealed no statistical difference between the groups. After entry, all patients had follow-up for the remainder of the admission.

The IP group subsequently had a significantly lower severity score based on the hospital course after entry (P < .01). Multivariant analysis separated the groups on the basis of the outcome variables (P < .0001). The control patients required ventilatory assistance, antibiotics, and diuretics more frequently than patients in the IP group. These data suggest that intercessory prayer to the Judaeo-Christian God has a beneficial therapeutic effect in patients admitted to a CCU."

Needless to say, these published data created a lot of interest in the medical community as well as communities of faith. Here were scientific data which positively affirmed the efficacy of prayer.

There was a revival of experiments, and a unit at the National Institutes of Health began to collect and collate papers which dealt with this subject. At present hundreds of papers have been indexed.

This revival of interest has been summarized well by Keith Stewart Thompson.¹³ He points out that "matters of the human spirit are not well suited to investigation by the scientific method."¹⁴

For example, the issue of controls is extremely difficult. How does one obtain a control group which is not prayed for? Remember that there are worldwide religious groups who pray regularly for the well being of all persons. Similarly, how does one prevent individuals from praying for themselves? Also, the quantitative measure of prayer is unknown. Are prayers of an individual as effective as the intercessory prayers of a large number of people?

Discussion Questions:

• What is your first experience of prayer?



• Is a scientific test of the power of prayer appropriate?



• Can science prove the existence of God?

7. Francis Galton, "Statistical Inquiries Into the Efficacy of Prayer," Fortnightly Review New Series 68: 125-135, August 1, 1872.
8. Ibid, p. 125.
9. Ibid, p. 128.
10. Ibid, p. 129.
11. Ibid, p. 130.
12. Randolph C. Byrd, "Positive Therapeutic Effects of Intercessory Prayer in a Coronary Care Unit Population," Southern Medical Journal, Journal of the Southern Medical Association, 81: 826-829, July 1988.
13. Keith Stewart Thompson, "The Revival of Experiments on Prayer," American Scientist 84 (November - December, 1996) pp. 532-534.
14. Ibid, p. 533.