Francis Galton

Statistical Inquiries into the Efficacy of Prayer

Review by Jenn Lindsay, 2011

Review by Jennifer Coleman, 2009

Review by Jenn Lindsay, 2011

Francis Galton, a productive anthropologist, statistician, meteorologist, explorer, forensics methodologist, eugenicist and Charles Darwin’s first cousin, was one of the great figures of 19th century human science. In his 1872 article "Statistical Inquiries into the Efficacy of Prayer," Galton seeks a result revealing “whether those who pray attain their objects more frequently than those who do not pray, but who live in all other respects under similar conditions.”

Galton notes that clergy frequently invoke a scriptural basis for the power of prayer and cites ways in which prayer surfaces in religious community: the Protestant church’s “biographies of its members, the journals of its missionaries, and the ‘united prayer-meetings’ of the present day” and Roman Catholic vows averting danger, pilgrimages to shrines, votive offerings and pictorial representations “of fatal accidents averted by the manifest interference of a solicited saint.” He notes the primâ facie support of prayer: the popular forgone conclusion is that prayer works because so many people keep doing it. Galton refuses to accept the efficacy of prayer on the basis of its historical universality, because as he says, then all forms of prayer, even Pagan, totemic, and Eastern, would have to be accorded equal status with the prayer of “orthodox believers.” The argument of universality quickly collapses and Galton is left with “a simple statistical question--are prayers answered, or are they not?” Galton sets out “to examine large classes of cases, and to be guided by broad averages” in order to deduce his conclusion. In his optimal study, “the same object is keenly pursued by two classes similar in their physical, but opposite in their spiritual state; the one class being prayerful, the other materialistic.”

In healing contexts, Galton reviews mitigating factors such as whether God graced nurses with more patience or surgeons with more precision, but focuses directly on the bottom line: did the praying patient recover more rapidly? For Galton, what constitutes an answer to a prayer? Galton names rapidity of recovery as the indication of prayer’s efficacy, not thoroughness of recovery or the subsequent mental state of the patient.

Galton could not locate any previous statistical studies on the efficacy of prayer, but writes, “the universal habit of the scientific world to ignore the agency of prayer is a very important fact.” He knows that the medical community is not unapprised to the use of healing prayer, but notes that if prayer were observed to be helpful it would be more broadly advised. Instead, medical practitioners “are unable to detect its influence.”

In order to evaluate the efficacy of prayer, Galton proposes data collection around throughly understood and frequently occurring conditions so as to minimize confounding factors, such as bone fractures and amputations. He proposes a division of two groups: “markedly religious piously befriended individuals” and “those who were remarkably cold-hearted and neglected.” Of course, studies in sociobiology and the healing affects of social contact are after Galton’s time, so he does not name “accompaniment” as a confounding factor, although in a contemporary reading of Galton his sample populations stand out more for being befriended or neglected than for their religious affiliation. This study could be taken as a survey of the effects of positive or negative attitudes on healing as much as those of prayer.

Galton surveys a number of studies confronting his same inquiry, beginning with a statistical study by Dr. Guy of the effect of prayer on the longevity of sovereigns; he notes they have the shortest lives of the affluent sample population despite being regularly invoked in prayer. The eminent clergy surveyed displayed no special longevity; their copious prayers too “appear to be futile in result.” Galton underscores this finding with his own study of Divines bearing “indifferent constitutional vigour.” Yet another study shows that missionaries too are “not supernaturally endowed with health.” Next Galton cites an inquiry into infant survival rate “among the children of the praying and the non-praying classes” wherein “the distribution of still-births appears wholly unaffected by piety.” He observes that constant collective prayers for the mental stability of nobility lack efficacy, as “religious madness is very common indeed.” He examines the lives and religious lineages of British leadership, from Lord Chancellors to ducal houses, and notes that no advantaged parties displayed outstanding devotion or “eminently prayerful qualities.”

Next Galton inquires as to whether seafaring vessels piloted by the pious or embarking on religious missions are safer than the vessels of the non-prayerful, namely, those of traders and of slave-dealers. He lists myriad confounders for such an inquiry, from trade route conditions to navigational skill, and detects no trends of higher success among the prayerful, and certainly no immunity to danger significant enough to be “entertained by insurance companies.” When Galton seeks instances wherein business success or security was enjoyed more frequently by the prayerful, he again cites a lack of support from insurance companies for the devout in business and cataclysmic matters. As Galton points out, an insurance arbiter does not ask when amassing character reference, “Does he habitually use family prayers and private devotions?”

After a listing a panoply of once religiously promoted claims that have now fallen into popularly recognized categories of suspicion, Galton makes his conclusion: “It seems to me clear that all belief in the efficacy of prayer, in the sense in which I have been considering it, must be yielded also.” The burden of proof urges this conclusion.

Galton issues two caveats to his dismissal of the physical efficacy of prayer: that prayer can provide emotional catharsis through the act of self-expression, and that this study does not disparage the possibility of communing in one’s heart with God. This second assertion is presented with several qualifications around the interference of imagination and personality, but Galton concedes that serene contemplation on the ideals of fellowship, responsibility, and the creative heritage of humanity have “much in common with the effort of communing with a God.”

Galton cannot be faulted for writing in his own age and failing to anticipate the subtleties of the endocrine and nervous systems or how behavioral and social factors affect health as documented in Chapter 3 of Harold G. Koenig’s Medicine, Religion, and Health. His methodology of surveying surveys provides a persuasive overview of result trends that does not seem to be as persuasively angled or strategically compiled to support a certain end as does Koenig’s collection. Galton’s caveat about the value of prayer at the end of the article, buffered as it is with another caveat questioning whether it actually puts someone in touch with a God, conveys a certain respectful open-mindedness. Galton is not vitriolic about religion; one even gets the sense that he wishes that the universality of prayer in history amounted to something other than habitual recitations or futile expenditures. But his survey collection, if it was compiled as impartially and evaluated as honestly as it seems to have been, delivers the conclusive result that prayer itself cannot conclude infirmity.

Review by Jennifer Coleman, 2009

“Statistical Inquiries into the Efficacy of Prayer.” By Francis Galton. Fortnightly Review, vol. 12 (1872), pp. 125-35.

The Essay

Sir Francis Galton’s 1872 inquiry into the efficacy of prayer was and is considered by many the definitive study establishing the lack of positive correlation between intercessory prayer and health.[1] Enduring as nearly bullet-proof, if perhaps not entirely unassailable, Galton’s study has fared better than Galton’s reputation. Biographical accounts accuse him of being everything from pro-social genius to proto-Nazi. As in the case of a bell curve, which he more or less invented, the truer picture emerges an average compilation of the facts from one extreme of a study to the other. But first, let’s consider his famous essay on prayer.

In response to a “published challenge to test the efficacy of prayer by actual experiment,” issued by an unnamed “eminent authority,” Galton rouses extensive data previously and meticulously compiled “for the satisfaction of my own conscience,” but then allowed to slumber for many years. He asserts that the efficacy of prayer is a “simple” and “perfectly appropriate and legitimate subject of scientific inquiry.” (125) Rejecting the “universality of prayer,” i.e. the ‘everyone’s doing it so there must be something to it,’ argument, “leaves us solely concerned with a simple statistical question.” (126) That question is: “are prayers answered, or are they not?”

He identifies two possible approaches to get his answer: first to examine a large class of cases and be guided by broad averages, or alternatively, to study isolated instances where prayer is claimed to have ‘worked.’ He adopts the former as “most trustworthy.” To accomplish his task he needs to “gather cases for statistical comparison, in which the same object is keenly pursued by two classes similar in their physical but opposite in their spiritual state.” (126) The two classes are “prudent pious people” and “prudent materialistic people.” The “same object” at issue is their health and prosperity as evidenced by longevity. The question thus becomes: does praying, or being the beneficiary of prayer, increase health as measured by longevity?

To study this question, Galton posits that statistics about the longevity of both the pious and impious are easily available. He includes a table comparing the mean age attained by sovereigns with that of other classes of persons, including clergy. (128) Sovereigns are the most prayed for persons in any state. Yet, they are the shortest lived of the 11 classes of “eminent men” tracked in the table. Simply put: “the prayer therefore has no efficacy.” Clergy are presumed to be the most “praying” or pious of the lot. Yet Galton finds that the clergy are not “in any way more long lived in consequence.”[2] Neither being prayed for more than others, nor praying more than others, enhances longevity.

To buttress what is already the conclusive point, Galton considers the cases of missionaries (prayed for, and praying) (129), still-births among praying and non-praying classes (130), the Nobility prayed for during public liturgy, and the youth of those “who have left a mark upon our English history,” as demonstrated by inclusion in prominent biographies of famous persons (131). In no case is it shown that the prayed for, or the prayerful, enjoy greater health, longevity, prosperity, social position, political privilege, immunity from disease, or other benefit. In fact, he notes that often prayerfulness or being prayed for correlates negatively; and put otherwise, that righteousness and virtue are often negatively related to prominence and success. (131-32)

He clearly thinks little of “divines” – the clergy – noting that like most praying persons they “are not practical” and make “bad coadjutor[s] in business matters.” Having clergy on a business board or as investors does nothing to improve business. In fact it probably is a disadvantage because “there is reason to expect that devout and superstitious men should be unreasonable.” (132) Insurance companies do not rate the risk of boats carrying missionaries any differently from ships operated for profit by profane men. (133) Churches, he notes, abandoned the practice of relying on God instead of lightening rods to spare them from accidents. (134) Churches befall calamity on a par with other buildings of the same class.

Wrapping up, Galton notes infamous examples of religious superstition only then recently abandoned: the belief the sovereign could cure by laying on hands, witches and exorcisms, trial by ordeal and duel, astrology, to name a few. By association, prayer’s time has come:

The civilized world has already yielded an enormous amount of honest conviction to the inexorable requirements of solid fact; and it seems to me clear that all belief in the efficacy of prayer, in the sense in which I have been considering it, must be yielded also. (134-35)

Pulling back a little, Galton avers that this conclusion does not negative “the fact that the mind may be relieved by the utterance of prayer.” (135) By this he means a physical, almost animal “voice convulsively sent out into space.” Yet he allows that human intellectual powers permit memory to travel back over past incidents and complex emotions and therefore humans pray “at length.” He also denies throwing any light “on the question of how far it is possible for Man to commune in his heart with God.” Such “a confident sense of communion with God must necessarily rejoice and strengthen the heart, and divert it from petty cares.” However, the same can be said about “those who on conscientious grounds are skeptical as to the reality of a power of communion.” These dwell on solidarity between themselves and what surrounds them, “through the endless reactions of physical laws, among which the hereditary influences are to be included.” Such reflection, like communion with God, “is quite as powerful in ennobling resolves” and can “give serenity during the trials of life and in the shadow of approaching death.”

The Man

Francis Galton (1822- 1911) was a first cousin to Charles Darwin. His interests included African exploration, invention, measurement, statistics, and eugenics. The last being the most controversial for scholars and scientists, and probably the most passionately pursued by Galton. Although he wrote an autobiography, he emerges more fully enfleshed in biographies written about him. The first, written by his protégé and the first Galton scholar, Karl Pearson, is widely considered a less-than-objective treatment of the man. Pearson’s four-volume effort includes many letters and drawings, and although effusive and deferential to Galton, the first generation experience and insight into the man are hugely compelling. Galton emerges as a genius, optimistic about society’s progress and committed to the belief that hereditary science could reduce human suffering and improve society.[3]

As seen through the letters included in Pearson’s volume 3, Galton emerges as a regular correspondent with his beloved sister Adele (who was physically disabled by curvature of the spine), and after Adele’s death, with her daughter, his niece, Millie. He is reported to have had a good marriage of long tenure with his wife, Louisa Butler, the daughter of a “divine” – a clergyman who died of heart disease shortly before they married.[4] Biographers agree that he suffered greatly because the marriage produced no children. They disagree over the extent to which he blamed his wife for being infertile, and the extent to which the marriage was a loving one, or one in which Galton acted cruelly towards a wife he regarded as an invalid.[5]

In a “biographical” letter to Pearson on Galton’s death, his niece Millie affirms her uncle’s agnosticism, but insists he was fond of discussing religious matters, reading the Bible aloud, favored William James’ Varieties of Religious Experience, and “was scrupulously careful not to say anything on religious topics that could possibly distress or injure the faith of anyone.”[6] Millie insists that her uncle prayed regularly and that he “had the will to believe… but it was the power that was denied him.” Id. These last observations surely seem an overwrought effort to recast the man responsible for one of the hugest uproars in society during his life, the effects of which persist.

Although famous for his study on the efficacy of prayer, Galton is infamous for his work in hereditary science for which he coined the term “eugenics.” Firmly committed to the belief that nature trumped nurture, Galton undertook studies and promoted policies that, if implemented, could, some opine would, have resulted in selective breeding, forced sterilization of genetically undesirable persons, and prioritizing the services and benefits of society for those deemed worthy to propagate while ignoring those who were not. His single-mindedness about heredity and eugenics were striking in a life otherwise marked by moving easily and quickly from one issue to another. Prayer was one of the issues that, at least professionally, Galton struck a blow and moved on. Eugenics was not. The co-opting of eugenics by the National Socialists to disastrous ends taints not only Galton’s work but also the man himself. (Compare Sandall with Comfort)

The Reaction

Charles Darwin wrote to compliment his cousin on his essay: “What a tremendous stir-up your excellent article on prayer has made in England and America!”[7] His niece Millie didn’t even mention the essay in her letter to Pearson. She did however rue the inclusion of a chapter on prayer by Galton in his Human Faculty (1883). She rejoiced to find it suppressed in a subsequent edition “at the urgent request of the publisher.” (Pearson, 448) She claims it was a materialistic notion of prayer “written under a complete misapprehension of the real Christian position with regard to it.” Id. She said he felt compelled to speak “even though it cost him the disapprobation and even the deep sorrow of some whose love and sympathy he most valued.” Id. It is easy to see in these remarks the impact of his essay on the efficacy of prayer and its reception by his family, publisher and others. In a letter to Milly written September 27, 1883, Galton comments that most people’s ideas about prayer are “habitually confused.” He rails against the “hopeless disaccord” of the average clerical mind. And in what is certainly a nod to his essay of efficacy of prayer, he states that belief in the objective efficacy of prayer is untenable. (Pearson, 471-72)

If Galton’s 1872 study was the high-water mark for scientific inquiry into the efficacy of prayer to improve health, then why are we doing spending millions of dollars still to study the same conclusively discredited phenomena? That is the question asked by Weissmann, who is less concerned about studies proceeding than with who pays for them. (Weissmann, 1279). Others argue that continuing such studies is not just purposeless but unethical.[8]


[1] Weissmann, Gerald. 2006. Editorial, “NIH Funding: Not a Prayer.” The FASEB Journal, vol. 20, pp. 1278-1280. Commenting on the STEP study funded mainly by the John Templeton Foundation, at a cost of $2.4 million, which found no positive correlation between intercessory prayer and recovery from coronary artery bypass graft (CABG) surgery, Weissmann stated: “Indeed the STEP trial had been scooped by an older, irrefutable, and far less expensive analysis: Galton’s essay of 1872.” (1279)

[2] The conclusion about clergy relies on date not reproduced in the essay, which Galton claims he reviewed thoroughly in his treatise Hereditary Genius, on the chapter on “Divines.” He declares somewhat peckishly: “I give abundant reason for all this, and do not care to repeat myself.” (129)

[3] Pearson, Karl. The Life, Labours and Letters of Francis Galton. 4 vols. Cambridge: University Press, 1914, 1924, 1930. Comfort, Nathaniel. 2006. Book Review, “Zelig: Francis Galton’s Reputation in Biography.” Bull. Hist. Med, 80, pp. 348-63, 353-354. In this review, Comfort actually writes a lengthy essay reviewing three recent biographies about Francis Galton. In the process, he actually produces a mini-biography of his own, drawing on the three reviewed books, and Pearson’s text.

[4] Sandall, Roger. 2008. “Sir Francis Galton and the Roots of Eugenics.” Soc. 45, pp. 170-76, 174-75.

[5] Comfort, 353. Pearson comments that Galton was not “fond of animals, nor had he a keen comprehension and love of young things [children].” Pearson, Vol. 3, 56. At the extreme is Sandal who speculates that Galton wrote his essay attacking the efficacy of prayer to mock his distraught wife who likely prayed nightly for children, and to express his anti-clericalism, including mocking his father-in-law, as “weak and unprolific men who bred weak and unprolific children.” Sandall, p. 175.

[6] Pearson, pp. 446-449, “Recollections of Francis Galton by Millicent Lethbridge.”

[7] Written by Charles Darwin to Francis Galton, November 8, 1872, reprinted in Weissmann at p. 1278.

[8] Paul, G. 2008. “The Remote Prayer Delusion: Clinical Trials that Attempt to Detect Supernatural Intervention are as Futile as the are Unethical.” J. Med. Ethics. 34:e:18, pp. 1-3. Paul asserts that such research entangles physicians in matters that are none of their business, and in ways that may actually harm patients. See also, Ragle, Brian. 2006. “Prayerful Science – More on the Relationship Between Prayer and Healing.” Skeptic, 12:4, p. 11. The STEP study discussed at note 1 indicated that patients who knew they were being prayed for did worse than the class who was unaware of being prayed for.