Intercessory Prayer, Group Psychology, and Medical Healing

Judith L Johnson & Nathan D Butzen. Miracles: God, Science, and Psychology in the Paranormal. Editor: J Harold Ellens. Volume 2: Medical and Therapeutic Events. Westport, CT: Praeger, 2008.

For many Christians, prayers for healing and the sick emanate directly from the Bible. The Bible discusses many cases of divinely inspired healing (e.g., Matthew 15:29-31: New American Standard Version [NASV]),1 and approximately 72 percent of Americans believe that praying to God can cure someone, even if science says the person does not stand a chance (Newsweek Poll 2003). Earlier, a 1996 Gallup poll found that 82 percent of Americans believe in the healing power of personal prayer and 77 percent agreed with the statement that God sometimes intervenes to cure people who have a serious illness (Poloma and Gallup 1991). Thus it is safe to say that prayer is biblically founded and believed to have a healing effect by a majority of Americans.

But what is prayer? Are there different types of prayer? Has prayer been scientifically proven to ameliorate physical problems and facilitate healing? What are some of the difficulties and limitations in the study of prayer and physical healing? This chapter is designed to address these questions and is organized in the following way. First, different types of prayer found in the research literature will be defined to provide the foundation for later discussion on prayer and healing. The chapter then moves on to outline selected empirical findings from both quantitative and qualitative research paradigms regarding prayer and physical healing. Finally, some of the difficulties associated with the study of prayer will be addressed. The chapter concludes with several summary statements regarding what we do know about prayer and physical healing, along with suggestions for future research.

Researchers in the area have identified up to 21 different types of prayer (McCullough and Larson 1999). Indeed, there is a prayer for physicians and healers that first appeared in print in 1793. The Maimonides’s daily prayer of a physician is said to have been written by a twelfth-century philosopher named Moses Maimonides and is often recited by newly graduated medical students. Later writers indicate that the prayer was likely written by Marcus Herz, who was a German physician and pupil of Immanual Kant. The Maimonides Prayer reads, in part, as follows:

In Thine Eternal Providence Thou hast chosen me to watch over the life and health of Thy creatures. I am now about to apply myself to the duties of my profession. Support me, Almighty God, in these great labors that they may benefit mankind, for without Thy help not even the least thing will succeed.

More recently, and out of the 21 identified types of prayer, empirical studies have made a distinction between the broad categories of ritual, conversational, meditative, and petitionary prayer (Poloma and Gallup 1991). Ritual prayer is that kind of prayer commonly found at formal religious services and is often found in liturgical church services.Conversational prayer involves talking with God in a small group in a normal tone of voice and in an informal, conversational style. It is thought to produce a greater awareness of God’s presence and be useful in teaching others how to pray. Meditative prayer has a variety of connotations; however, it is characterized by a relaxing and “being with God” that is thought to reduce expectations that people should be doing something in prayer. A common meditative prayer may start with relaxation and thankfulness, combined with openness to hearing God’s word. When it comes to prayers directed toward healing, petitionary prayers are those that ask for divine intervention into sickness and life-threatening illnesses. It is primarily this type of prayer that is the focus of this chapter.

It is noteworthy that there are many terms used in the literature that refer to prayer-like behavior. These terms are not necessarily interchangeable. Terms such as psychic healing, nonmedical healing, spiritual healing, miracle healing,and laying on of hands have been used in published studies. Hence there is no agreement on language or on definitions when referring to prayer, prayer-like behavior, and physical healing.

In terms of healing, petitionary prayers may be further distinguished according to who is praying for whom or whether there is physical distance involved (distant intercessory prayer). Furthermore, the frequency and intensity of prayer and formal versus private versions of prayer have not been adequately addressed as variables that may or may not be important (Krause 2000) in studying possible links between prayer and physical health. There has also been little empirical attention addressing other aspects of prayer such as how many people are praying, or their faith traditions, or whether the person being prayed for has a religious or nonreligious worldview.

Empirical study of prayer and physical health has yielded inconsistent findings. Indeed, some authors have questioned whether it is even appropriate, both theoretically and methodologically, to claim to study the effects of prayer (Masters 2005). In terms of inconsistent empirical findings, McCullough and Larson (1999) have suggested that failure to consistently relate frequency of prayer to measures of health likely results from methodological problems. Some common design problems include use of single-item measurement of constructs, different and uncontrolled sample characteristics, and choice of outcomes. Furthermore, authors typically have failed to include appropriate design or statistical control of extraneous variables such as baseline health, religious commitment, personality, and ethnicity (McCullough and Larson 1999). Because of this, many extant studies of the relation between prayer and health may not be comparable, and there is also an absence of replication of findings in the literature. Limitations of research designs and criticisms of this field of study will be more fully discussed subsequently.

Empirical Findings

By far, the most researched form of prayer directed toward healing is distance intercessory prayer (IP), defined as prayer offered for the healing benefit of another person (Tlocynski and Fritzsch 2002). This prayer is directed toward the well-being of others and may be performed by strangers, family members, acquaintances, or service providers. The one being prayed for may or may not be aware of the prayer on his or her behalf. IP is directed toward God or a transcendent being, and the person praying believes that this may effect change and promote healing in another person.

From a historical perspective, perhaps one of the most famous studies of IP was published by Byrd in 1988, and this set the stage for a firestorm of controversy that continues to the present. In essence, this study used a randomized double-blind trial of 393 coronary care unit (CCU) patients, who were prayed for by Christian prayer groups (intercessors). The patients who were prayed for demonstrated fewer instances of congestive heart failure, pneumonia, and cardiopulmonary arrest. Furthermore, they exhibited less need for antibiotics, intubation, and diuretics. Byrd (1988) concluded that IP had a beneficial effect on CCU patients; however, later authors have noted that the Byrd (1988) study examined 29 outcome variables and only established six positive outcomes for the prayed-for group (Sloan, Bagiella, and Powell 2001). This fact, combined with the failure to control for multiple comparisons, calls into question whether IP truly had an effect on these six outcomes (Sloan, Bagiella, and Powell 2001).

Since this early study, there have been many empirical and quantitative studies reported in the research literature. As noted earlier, findings are often contradictory. For example, Harris et al. (1999) reported on a randomized trial of distant IP on various outcomes with coronary care patients. These authors randomly assigned coronary care patients into two groups. The control group received the usual medical care, and the treatment group received distant prayer from interdenominational Christians for outcomes such as faster recovery or no complications. The group that received prayer demonstrated significantly better progress on such things as speed of recovery; however, Chibnall, Jeral, and Cerullo (2001) note that there have been similarly designed studies that have not produced conclusive findings.

For example, a long-awaited study that used state-of-the-art scientific procedures found no effect for IP (Benson et al. 2006). More specifically, distant IP had no effect on whether cardiac bypass surgery patients experienced complications. In this study, patients were randomly assigned into three groups: group 1 received IP after being told they may or may not receive prayer; group 2 did not receive IP, after being told they may or may not be prayed for; and group 3 received IP after being told they would receive it. The patients in group 2, the group not receiving prayer, fared slightly better than the patients in group 1, who did receive IP. A provocative finding was that patients in group 3, who knew they were being prayed for, fared the worst. Complications within 30 days of surgery occurred as follows: group 1, 52 percent; group 2, 51 percent; and group 3, 59 percent. One of the cardiologists who participated in this study observed that one possible reason that group 3 had a poorer outcome was that knowledge of being prayed for may have had an unexpected side effect of frightening the patients—hence accounting for greater complications; however, this remains to be seen. It is noteworthy that this particular study involved I P, not prayer for self or prayer from close friends and relatives.

Since single studies do vary by research design, participant sample, and procedures, it is often difficult to draw a singular conclusion to the question of whether IP affects healing. One way to attempt to summarize studies is through meta-analysis, which is when the researcher combines the findings from a number of studies by statistically integrating the various sets of results (Sprinthall 2007). Thus the researcher collects a number of studies focused on prayer and healing and reviews them. Statistics are used for estimating the effect size to predict the actual population effects. An effect size of zero indicates that the independent variable (IP) had no effect on the dependent variable (various healing outcomes such as need for surgery or time to recovery). An estimated effect size of 0.8 would indicate a very strong effect for IP on healing outcomes such as surgical complications.

In meta-analysis, which uses a number of different studies, an effect size of 0.8 would be very strong evidence for the effect of prayer on healing insofar as the effect of prayer has cut across different research settings, participants, and methods (Sprinthall, Schmutte, and Sirois 1990). Hence a better understanding can be achieved regarding the effect of prayer on healing through use of meta-analysis. This is particularly the case when different studies yield different findings regarding this relationship.

There have been two recent meta-analyses on the effect of IP on healing outcomes. Masters, Spielmans, and Goodson (2006) included 14 studies in their meta-analysis. To be included, the studies (1) used IP as an intervention in either physical or mental health disorders, (2) were sufficiently empirical to provide data to be used in the meta-analysis, (3) used a control or comparison group, and (4) had participants who were blind as to whether they were in the IP versus the control group. Medical/healing outcomes ranged from events within cardiac patients (Aviles et al. 2001) to complications related to dialysis (Matthews, Conti, and Sireci 2001). Masters, Spielmans, and Goodson (2006) also examined whether certain aspects of study participants and particular research designs had an impact on overall findings. Specifically, the impact of types of participants, frequency and duration of prayer intervention, and assignment of participants to experimental conditions was assessed to establish whether these factors had an influence on IP and outcome variables.

The meta-analytic findings from the Masters, Spielmans, and Goodson (2006) study were not positive. These authors found no support for any effect of IP on medical/health outcomes. Furthermore, study design characteristics, such as types of participants and their assignment to groups and frequency of prayer, did not moderate or influence any potential effect of IP on outcome variables. They concluded, “There is no scientifically discernable effect for IP as assessed in controlled studies. Given that the IP literature lacks a theoretical or theological base and has failed to produce significant findings in controlled trials, we recommend that further resources not be allocated to this line of research” (Masters, Spielmans, and Goodson 2006, 21). Hence this meta-analytic review found such a notable lack of support for IP on influencing medical/health outcomes that the authors could find no justification for further study on the topic.

A more recent meta-analysis was a bit more positive. Hodge (2007) examined 17 studies on IP and health. Inclusion criteria for these studies were as follows: (1) studies used IP as an intervention that was (2) used with a population of clients or patients for healing. Furthermore, included studies were designed to examine the efficacy of the intervention (prayer) using double-blind randomized control trial methodology (RCT). In RCT, research participants and the researcher are kept blind, or uninformed, about who is receiving the IP. Participants are randomly assigned to either a prayed-for group (the experimental or treatment group) or a group not receiving prayer (the control group). Single case studies and studies using personal prayer (as opposed to IP) were excluded from Hodge’s (2007) study. Across the 17 studies, outcomes varied from mortality, complications, and major events within recovering cardiac bypass patients (Benson et al. 2006) to abstinence from alcohol abuse (Walker et al. 1997).

Hodge’s (2007) meta-analysis indicated significant, but small effect sizes for IP across the 17 reviewed studies. Although this is generally a positive finding, it is interesting to briefly consider these studies when grouped into significant versus nonsignificant findings.

Five of the 17 studies did not find significant effects for IP on various healing outcomes with diverse medical ailments. Prayer was not found to have a significant effect on patients receiving treatment for cardiac bypass surgery (Benson et al. 2006), alcohol abuse (Walker et al. 1997), kidney dialysis (Matthews, Conti, and Sireci 2001), or psychiatric disorders (Mathai and Bourne 2004) and on patients receiving heart surgery (Seskevich et al. 2004).

Three of the 17 studies found significant effects for IP with cardiac patients (Byrd 1988; Harris et al. 1999; Furlow and O’Quinn 2002). Three additional studies found significant effects for IP with AIDS (Sicher et al. 1998), bloodstream infections (Leibovici 2001), and women receiving treatment for infertility (Cha and Wirth 2001). One study found significance for in-person IP but not for distance prayer for women with arthritis (Matthews, Marlowe, and MacNutt 2000).

Finally, five of the studies found a favorable trend for a positive effect of IP on health outcomes, despite lack of statistical significance. Three of these studies examined the effect of IP on cardiac patients with heart disease (Aviles et al. 2001) and those receiving heart surgery (Krucoff et al. 2001, 2005). Two older studies found a positive trend with patients with rheumatic disease (Joyce and Welldon 1965) and children with leukemia (Collipp 1969).

It is important to note that both the Masters, Spielmans, and Goodson (2006) and Hodge (2007) meta-analyses only included quantitative studies involving between-group comparisons and use of inferential statistics to gauge the effectiveness of IP. By its nature, meta-analysis does not include qualitative studies or single case studies, where an individual’s subjective experiences regarding prayer and healing can be examined. This being noted, the quantitative research paradigm underlying techniques such as meta-analysis is inconclusive with respect to IP. Along these lines, Hodge concluded (2007, 185), “Indeed, perhaps the most certain result stemming from this study is the following: The findings are unlikely to satisfy either proponents or opponents of intercessory prayer.”

Qualitative Findings

Although the above two meta-analytic studies exemplify quantitative work studying the effect of prayer on medical healing, it is important to note that nonexperimental studies on prayer generally provide favorable outcomes (Koenig, McCullough, and Larson 2001). Furthermore, qualitative and anecdotal reports of prayer and healing abound. These studies range from single case studies to small group studies, with anecdotal reports from patients with a variety of diseases and medical problems. As noted earlier, there are compelling arguments from both theologic and scientific perspectives against the wisdom of subjecting prayer and healing to empirical study (Masters 2005). Hence first-person reports of healing provide a different perspective on the relation between prayer and healing.

Single case studies are reported in many different venues. For example, an Internet Google search for “prayer and healing” found close to 3 million hits, with articles ranging from newspaper reports to publications such as the U.S. Catholic. Anecdotal reports of healing are numerous and often dramatic. For example, there are reports of cancerous tumors that miraculously disappear and healing from terminal illnesses. Reports from both patients and their treating physicians are found.

It is of interest to note that there are entire books devoted to this subject, such as Dr. Larry Dossey’s Healing Words (1993) and Prayer Is Good Medicine (1996). Since there are so many individual reports of (miraculous?) healing, for the purposes of this chapter, one exemplar will be described (Dubois 1997). Oncology nurse Cindy Thomas took a parish-based class on healing in 1984 and subsequently added prayer for her patients as she tended to them. She noted immediate results, when patients told her they felt better or slept better than before. She then started praying for guidance as she drove to work as well as individually praying for her patients. Some patients began to ask her to pray with them, and most slept peacefully through the night. Thomas tells a particularly compelling story about a young woman admitted to Providence Hospital in Everett, Washington, who had a deadly form of cancer in the lining of her heart. Thomas worked with the family and learned they had already experienced the tragic deaths of two children. According to a report,

Thomas took the woman’s hands and said, “You’ve had enough tragedy. It’s time to pray for a miracle. You’re due for one.” At 1 A.M. the next morning, the pathologist called the nurses’ station. He sounded confused. “This is a weird thing,” he told Thomas. “Something made me go back to the lab and look at the slides (with the fluid specimen taken from the woman’s heart lining). And they’re completely negative.” “That sounds like a miracle,” Thomas said. “I, I guess it does,” stammered the pathologist. An ultrasound the next morning confirmed the new test results. (Dubois 1997, 3)

Individual reports of healing through prayer are difficult to verify through the scientific method, which typically relies on larger group studies. They are also difficult to examine since they often may involve errors within the diagnostic or prognostic processes, and health professionals are understandably reluctant to divulge such information. Perhaps it is safe to say that many do believe in and report medical miracles and that this is sufficient to conclude that they do occur. Indeed, valid criticisms of the scientific study of prayer and healing are so strong that qualitative reports may have more veracity than scientific studies.

Doctrinal Differences in Beliefs about Healing Prayer

It is significant to note that within various Christian denominations, there are many different views on praying for the sick. Different faith traditions tend to argue that certain forms of prayer are more effective than others, and these discrepancies are often based on a doctrinal emphasis on specific scriptures. For example, some Christians believe that when dealing with sickness, it is important to use the prayer of Jesus for the will of God to be done that he modeled while praying in the garden of Gethsemane in Matthew 26:39-44. Other Christians may argue that when trying to alleviate sickness, it is important to follow Christ’s sage advice that “this kind does not go out except by prayer and fasting” (Mt 17:21). Another group of Christians believes that Satan has significant power to cause sickness, and only by engaging in spiritual warfare can someone be healed of a serious illness.

Certain faith traditions believe that prayer for healing requires a certain level of faith to work, while others believe that “faith like a mustard seed” can accomplish miracles, including the healing of the sick (Lk 17:6). Some Christians believe that God heals who he will and has predestined all of the ways of a man, while others believe that it is possible to change God’s mind on a number of issues that could encompass healing. With such a diversity of theological beliefs in regard to prayer for healing, it is clear that major difficulties would exist in standardizing the form and content of prayer that is offered for healing. There is not room to completely explain all of the theological implications encountered when trying to conduct this type of research, but these examples suffice to illustrate the diversity of prayer practices encountered when evaluating prayers for the sick in the Christian community.

Practical Problems with Prayer Research Based on Doctrinal Differences

Differences in Christian doctrines of praying for the sick could play out in scientific studies. For instance, consider an intercessor who believes that a so-called healer or someone with a gift of healing must touch or lay hands on a sick person so that he or she can be healed. If this person were asked to engage in distant IP, he or she would likely experience cognitive dissonance because this is not how the person has been taught that prayer is supposed to work—or at least be the most effective. The argument could be made that when asked to do distant IP for a research study, intercessors who practice any different rituals for praying than those required by the study might doubt the efficacy of the prayer and thus not have faith that it will work.

Benson et al. (2006) note that many intercessors felt constrained by the limits or methodological controls that were used to ensure a good empirical design. Rather than pray from a distance, the intercessors were accustomed to having personal contact with the families and individuals for whom they were interceding. Perhaps this is a confound to the research, and typical in-person IP could be more beneficial to a person’s health, if simply for the increased social support that patients receive during this time. In fact, this is consistent with the empirical study of Matthews, Marlowe, and MacNutt (2000) mentioned earlier, who found an effect for in-person prayer but not for distant IP. Of course, this type of finding would not prove that there is a God or that prayer works. However, in an indirect way, this conceivably shows that the way God’s people function when a member of their faith group becomes sick does actually have beneficial health effects.

David Myers (2000), an author of introductory psychology textbooks and an outspoken critic of the empirical investigation of prayer, still commends a multiplicity of research studies on people of faith. Some of these studies have found that people with an active faith are healthier on a variety of health and mental health domains. Myers points out, for example, that after controlling for other pertinent variables, people of faith cope better with life events and report more happiness, while actually living longer as well. This latter finding remains salient even when healthy lifestyle choices are controlled for.

Further Challenges in the Study of Prayer and Health

As noted earlier, there have been critics of the theoretical, theological, and scientific fallacy of subjecting IP to empirical study. Masters (2005) provides an excellent treatise on this issue. Although the reader is referred to Masters’ publication, it is worthwhile to briefly outline some of his concerns. First, many quantitative studies of IP and health are not properly grounded in theory, perhaps because there is no theory that is applicable or appropriate. If a group that is prayed for does better than one that is not (the control group), why would this be the case? Masters notes that God would not be preferential toward one group versus the other simply because an individual who needed healing ended up in a control group. Similarly, many studies do not examine whether those in the control group were prayed for by those close to them, which leads to another troubling theoretical conundrum: Why would prayer by a stranger (intercessor) be more effective than prayer from loved ones? Similarly, if IP does not have an effect, does this mean that God did not want to help or that prayer is useless? There are no theologically sound answers to these questions.

This lack of answers to theory-driven questions confounds the ability of the research to provide meaningful findings. Masters (2005) also notes that methodological choices of instruments used and samples chosen are similarly hampered by the lack of a cogent theory to guide the study of IP and health. The choice of outcome measures often lacks a rationale. Similarly, there is no theory to guide the choice of patient samples or of the intercessors themselves.

Masters (2005) presents convincing arguments that empirical studies are not appropriate to the study of IP and advocates that research resources be allocated to other, more appropriate religious/spiritual topics that can be studied scientifically. Masters concludes (2005, 268), “It is further argued that the experimental methods of science are based on important assumptions that render them ill-equipped to study divine intervention. As a result IP studies are seen as a distraction from more appropriate work that should be done in the areas of religion and health.”

Along these lines, some writers have identified potential ethical problems associated with concluding that IP has a positive effect on health variables, when it actually does not, and strongly caution that prayer as an adjunct to medical interventions should not be prescribed. Although directed toward physicians, Sloan, Bagiella, and Powell (2001) note that issues of coercion, privacy, doing harm, and discrimination may arise should a physician suggest prayer or religious/spiritual activities to a patient, particularly in the absence of a sound body of research literature validating the effect of prayer on healing. The reader is referred to this work for a more in-depth discussion of these ethical considerations.

It is clear that some of the criticisms of the methodology for the studies that do exist on prayer and healing include significant problems operationalizing constructs like prayer, faith, and intercessory. It is also very difficult to reduce error variance among those praying. For instance, do some people pray longer than others? Are there some who pray outside of the appointed times to pray for the suffering victim? If someone has a gift of compassion and is in close communion with God, is it difficult for that person to stop “praying without ceasing”? Some researchers have made significant efforts to control for these factors, but these efforts beg the question whether a scripted prayer can truly be considered intercessory.


Given the conclusions of the two meta-analyses provided by Masters, Spielmans, and Goodson (2006) and Hodge (2007), it is difficult to conclude that IP has an effect on healing. However, this conclusion must be tempered by the limitations of the quantitative research tradition and whether quantitative group studies of distant intercessory prayer are even an appropriate tool to study prayer, faith, and health. Furthermore, there is a lack of theological rationale and integrated theory guiding the empirical research to date (Masters 2005). This lack may well explain the absence of sound and replicable empirical findings.

Perhaps researchers should listen to the advice of both Myers (2000) and Masters (2005), suggesting that it is time to put resources toward more measurable and clear domains than the effect of IP on health; however, this suggestion does not preclude the consideration of prayer as a predictive factor for many other positive outcomes. For instance, Butler, Stout, and Gardner (2002) found that married couples who prayed together had attitudes that enhanced conflict-resolution skills and more productive problem-solving skills. They suggest that further research should be conducted to determine whether prayer could be used as an effective intervention for religious couples in therapy. Case and McMinn (2001) found that spiritual practices, such as prayer, serve to mediate anxiety for religious psychologists, and these psychologists also perceive prayer to be one of the practices important to healthy functioning in their professional roles. So, clearly, it is possible to use empirical research to demonstrate that prayer, or at least the ritual of prayer, can have positive effects on mental and psychological health outcomes. The difference is the consideration of the ritual of prayer as an effective coping mechanism or practice within a constellation of other religious and spiritual variables versus an attempt to prove that the content of a prayer is directly responsible for an outcome such as better health. The latter approach approximates testing God and/or prayer to deliver a predetermined outcome, while the former allows for the act of prayer to be a helpful practice, without relying solely on the prayer’s content.

Although IP has been the dominant area for research into prayer and health outcomes, it may well be that directions for future research should include more emphasis on qualitative research such as single case studies. This will not negate the criticisms put forth by several authors, particularly those criticisms aimed at the lack of theological or theoretical rationale. However, single case studies that are subjected to verification processes may continue to be descriptive of individual experiences and be heuristic for future researchers.