Thursday, July 26, 2018

Josh Rasmussen on prayer studies

In this post I'm going to quote a paper by Christian philosopher Josh Rasmussen on the limitations of prayer studies, and how skeptics draw fallacious inferences from prayer studies:


Proof #2 - Statistically analyze prayer
Here’ the basic argument:
Premise 1: God never answers any prayers.
Premise 2: If God is real, then God at least sometimes answers prayers.
Conclusion: God isn’t real; he’s imaginary.
This proof has a cool feature: it’s logically valid. That means that if the premises are true, then the conclusion is true. But are the premises true? Have they been proven? Let’s consider each premise:
Premise 1: God never answers any prayers.
The author says that we can put premise 1 to the test through science. And when we do, he thinks the results are decisive. He states: “we have scientifically proven that God does not answer any prayers on earth.” Is that true? Let’s look at the evidence he cites. 
To start, consider the quote from the Boston Globe:
One of the most scientifically rigorous studies yet, published earlier this month, found that the prayers of a distant congregation did not reduce the major complications or death rate in patients hospitalized for heart treatments.

The Boston Globe article doesn’t cite the primary source, but I did some digging and found it here. Interestingly, the scientists who conducted the test report this

             “the lowest absolute complication rates were observed in patients assigned to off-site prayer.” 
And this article cites this same experiment as lending support to the hypothesis that intercessory prayer has a positive effect. Huh… 

Well, it is true that the measured effect of prayer wasn’t dramatic: it didn’t reduce “the major complications.” 

But if you think about it, you might not expect the effect to be dramatic even if God regularly answers prayers of this type. For as the Boston Globe article points out, “Nearly 90 percent of all the patients participating said someone was praying for them separate from the prayers commissioned by the researchers. So the study, in effect, measured whether distant prayer provided an added benefit to personal, local prayer” (emphasis added). In other words, most of those who “weren’t prayed for” received heart-felt prayers from loved ones. We might expect, then, that prayers from strangers wouldn’t bring much, if any, additional benefit. Anyway, the first study didn’t show that prayer had no effect; it appears the opposite. 

Consider next the 17 studies that allegedly found no significant effect for prayer or other healing methods. …Now where are those primary sources? Lots of websites tout the Boston globe quote, but none give a primary source. Interestingly, this article from The Telegraph copies the Boston Globe quote word for word without even citing the Globe! 

Remind me, how do rumors get started? 

Here’s the good news: I eventually found an article (2007) about 17 studies on distant prayer, and it actually cites a primary source! Now for the ironic news: the article says this: “when the effects of prayer are averaged across all 17 studies, controlling for differences in sample sizes, a net positive effect for the prayer group is produced” (emphasis added).  …So far, the evidence for Premise 1 isn’t inspiring much confidence. 
But let’s consider the famous 2006 study. It’s the largest of its kind, and it shows prayer not having a positive effect (primary source here). The study is limited to the following kind of prayer:
For physical wellbeing
At a distance
For people you don’t know
Without feedback on the patient’s condition
Scripted by the researchers
Keep in mind that those in the “not prayed for” group likely did receive prayer. The study reports that “almost all subjects [~95%] believed that friends, relatives, and/or members of their religious institution would be praying for them” (p. 937). And this doesn’t include the prayers from the patients themselves. So, the study only really addresses how much additional health benefit might result from the scripted prayers of strangers. 
The study suggests, then, that there’s not much, if any, additional physical benefit from this type of prayer from strangers. Note: there might still be some benefit: the researchers point out that “the magnitude of the reduction could be smaller than the 10% that our study was powered to detect” (p. 941). But if there’s a benefit, it is small. That’s interesting; and for truth-seekers, it’s good to know.
Should we infer from this particular study that no types of prayers have a measureable effect? Are there studies on other types of prayers? There are. Actually, there are quite a few double blind studies that report a positive health effect for certain prayers. That’s fully compatible with other studies not measuring an effect. (See these studies.) Each study controls different variables. This research article reports [with citation] that “Of 212 published studies that have assessed the effects of spiritual factors on health care outcomes, 75% report a positive effect, 17% report no effect, and 7% report a negative effect” (p. 1193). So, if anything, we seem to have evidence against Premise 1. We certainly haven’t “scientifically proven that God does not answer any prayers on earth.” The evidence is more complex. Reality is more complex. 
To be clear, I am not aiming here to show that God does answer prayers. Maybe every study that suggests a positive effect is flawed or is explicable in terms of non-divine factors. I’m only investigating whether we have evidence that shows that God doesn’t answer prayers. We want to see if Proof#2 succeeds. In light of the data we have so far, it appears not. Perhaps we should keep investigating. 
We should also keep in mind that the studies cited are limited to prayers for physical health. It could be that God setup a universe in which prayers for moral reform, better relationships, and wisdom are the most likely to have an effect. That’s a possibility not addressed by Proof # 2.
Consider now premise 2: if God is real, then God at least sometimes answers prayers. 
Ironically, it has been argued that if God were real, there wouldn’t be breaches to the natural order. But even if we don’t go that far, we might well expect a perfectly rational being to want a very orderly world—one that’s governed by predictable rules (be they deterministic or probabilistic). Perhaps a perfect being would rarely, if ever, cause a breach in the normal workings of the world. In that case, we wouldn’t find our prayers to have effects over and above the effects predicted by the laws that govern our universe, our bodies, and our minds. What if God has granted us the responsibility to learn how to heal one another? That’s certainly possible. But Proof#2 doesn’t address this possibility. Thus, Proof#2 doesn’t show that its second premise is true—far from it. 
The value of digging deep

The author challenges us to open our eyes and look at the data. To see the truth, we must actually look at the data on both sides. This takes courage. It takes persistence. It takes intellectual humility. I applaud this attitude; its reward is a deeper understanding of reality as it really is. So, thanks for the challenge. It’s a good one. I recommend it to my religious friends and to humans in general. To see the truth, we must go deep in our investigation. Then we’ll make progress—real progress.


  1. //I’m only investigating whether we have evidence that shows that God doesn’t answer prayers.//

    Why not also investigate whether we have evidence that an undetectable dragon doesn't exist in my garage?

  2. Stephen Galanis

    "Why not also investigate whether we have evidence that an undetectable dragon doesn't exist in my garage?"

    You should have gone with the original, i.e., John Wisdom and Antony Flew's invisible gardener instead. Carl Sagan took his dragon in the garage from them.