STEPP Study — Proximal Intercessory Prayer and Sensory Improvement in Mozambique (2010)
The story
Skip to the verdict ↓A prospective peer-reviewed study by Indiana University researchers measured statistically significant improvements in hearing and vision in 24 Mozambican subjects following proximal intercessory prayer.
The STEPP study (Study of the Therapeutic Effects of Proximal Intercessory Prayer) was conducted in rural Mozambique by Candy Gunther Brown (Indiana University Department of Religious Studies) and colleagues. Published in the *Southern Medical Journal* in September 2010, it evaluated 24 Mozambican subjects reporting impaired hearing (14) or vision (11) before and after receiving proximal intercessory prayer from local Christian ministers.
Using an Earscan 3 audiometer and standard "Illiterate E" vision charts, researchers measured statistically significant improvements in both sensory domains (hearing: p<0.003; vision: p<0.02). Authors noted that effect sizes exceeded what has been documented in prior hypnosis and suggestion research.
The Study Design
The study did not use a randomized control group, and assessors were not blinded to treatment condition. Subjects knew they were receiving prayer. Baseline medical diagnosis of impairment was not independently verified by audiologists or ophthalmologists, and no follow-up measurement was conducted. The sample size was 24 subjects.
No replication study has been published. The study appeared in a peer-reviewed venue and remains the most-cited empirical data point in the prayer-and-healing literature.
It happened — and nature accounts for it.
Reviewer Notes
Miracles Jar weighs each claim two ways — how extraordinary it would be, and how strong the evidence is.
Assessed by Miracles Jar AI
Peer-reviewed but methodologically weak; results are suggestive but not sufficient to rule out demand effects or placebo response.
The evidence points strongly toward a natural explanation, and the case is a weak one for authenticity.
The reasoning behind that assessment: results were measured with calibrated instruments (Earscan 3 audiometer, standard vision charts) and published after peer review, but the study has serious methodological limitations — no blinded assessors, no control group, no follow-up measurements, tiny sample (n=24), and a demand effect (participants knowing prayer was occurring) that could substantially inflate self-reported and even behavioral response. The lead author (Candy Gunther Brown) is a religious studies scholar at Indiana University, not a clinical audiologist, and critics note the absence of independent medical verification of pre-existing conditions. No attempt to replicate the study has been published.
The original body framed the methodological points as "concerns" and "sustained criticism from clinicians and methodologists." The specific issues: (1) no randomized control group; (2) assessors were not blinded to treatment condition; (3) subjects knew they were receiving prayer, creating a demand effect; (4) baseline medical diagnosis of impairment was not independently verified by audiologists or ophthalmologists; (5) no follow-up measurement was conducted; and the sample size of 24 is too small to control for regression to the mean.
Demand effect is identified as the leading alternative explanation among critics: behavioral and self-report changes are well-documented in unblinded studies. The authors' own claim that effect sizes exceeded prior hypnosis and suggestion research is weak supporting evidence because it is the authors' own claim and not independently replicated.
Sources include the primary study (Brown CG, Mory SC, Williams R, McClymond MJ, *Southern Medical Journal* Vol. 103(9):864-869; PMID 20686441), Brown's 2012 book *Testing Prayer: Science and Healing* (Harvard University Press), and a methodological critique by Tom Rees / Patheos Epiphenom (2011, "A Truly Dreadful Study Into the Effects of Prayer"), described as summarizing the demand-effect and control-group limitations — not peer-reviewed but substantively accurate.
Evidence ledger — what the verdict rests on
Published in a peer-reviewed medical journal (Southern Medical Journal) with statistically significant results (hearing p<0.003, vision p<0.02)
The only such study measuring sensory outcomes before/after prayer with calibrated instruments
No control group, no blinded assessors, no independent medical verification of baseline conditions
Standard methodological critiques that substantially limit causal inference
Demand effect: subjects knew they were receiving prayer; behavioral and self-report changes are well-documented in unblinded studies
This is the leading alternative explanation among critics
Effect sizes reportedly exceeded prior hypnosis and suggestion research, which the authors note
Authors' own claim; not independently replicated
What would raise the meter: Documented recurrence in cases with no expectancy pathway — or records ruling out functional overlay — would raise the meter.
What would lower it: Evidence of symptom relapse, revised diagnosis, or undisclosed treatment would lower the evidence bar.
How we weigh every claim — the full method, deductions and all →
The natural explanation
The leading natural account for this case is expectation, suggestion & the placebo response. Read what it explains — and where it stops.
Sources
Tagged by proximity to the event. Primary sources are direct or contemporaneous; tertiary are downstream retellings.
- 1.Primaryacademic
Brown CG, Mory SC, Williams R, McClymond MJ, "Study of the Therapeutic Effects of Proximal Intercessory Prayer (STEPP) on Auditory and Visual Impairments in Rural Mozambique", 2010· no public link
Southern Medical Journal, Vol. 103(9):864-869; PMID 20686441 — peer-reviewed primary source
- 2.Secondarybook
Candy Gunther Brown, "Testing Prayer: Science and Healing", 2012· no public link
Harvard University Press; provides extended context for the study findings
- 3.Secondaryother
Tom Rees / Patheos Epiphenom, "A Truly Dreadful Study Into the Effects of Prayer (methodological critique)", 2011· no public link
Summarizes the demand-effect and control-group limitations; not peer-reviewed but substantively accurate
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