Check out the short summary on Wiki, https://en.wikipedia.org/wiki/Efficacy_of_prayer

for a start on scientific studies of prayer. It's a topic in the psychology of religion

There is a summary at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802370/

At Wiki on intercessory prayer: https://en.wikipedia.org/wiki/Studies_on_intercessory_prayer

I'd start with a good psychology of religion textbook.

The Psychology of Religion, Fourth Edition: An Empirical ApproachJul 15, 2009

by Ralph W. Hood Jr. PhD and Peter C. Hill PhD

Psychology of Religion: Classic and ContemporaryNov 22, 1996

by David H. Wulff

The Psychology of Religion, Third Edition: An Empirical ApproachAug 6, 2003

by Bernard Spilka PhD and Ralph W. Hood Jr. PhD

Thank you, Hendrika, for the certainly very useful reading list. 

But in addition I am sure that there are a variety of viewpoints and more personal opinions held across the varied membership of the RG community from which I (and we) can learn -- even if psychologists of religion would perhaps, in their scholarly way, see them as somewhat naive.

So I hope for further answers to my question...

Jim

PS Incidentally my question is about the reality (wassat?) we experience, rather than human psychology.

Here is a link to the classic Galton paper

http://galton.org/essays/1870-1879/galton-1872-fortnightly-review-efficacy-prayer.html

and here is a double-blind trial

http://www.sciencedirect.com/science/article/pii/0021968165900408

“More things are wrought by prayer Than this world dreams of.”

On one sense, I'm trying to figure out how the "world" dreams...

On another... some of us would consider "one thing" being "wrought by prayer" as being "more" than I would ever dream of.

But... how would anyone be able to find a causal link between a prayer and some occurence in the real world? given that Hume had enough trouble inferring causality from billiard balls...

--> Geoff Carver

"I'm trying to figure out how the "world" dreams".

It's poetic -- I guess Tennyson means something like "than human beings currently realize"

"But... how would anyone be able to find a causal link between a prayer and some occurence in the real world? given that Hume had enough trouble inferring causality from billiard balls..."

Yes, I agree that the notion of causality is far from clear. You imply you would not accept that prayer is itself an occurence in the real world?

--> Hosny Abbas

I feel that the poet (Tennyson) does indeed suggest something like your comment -- that his poetic King Arthur does have understanding of God's purpose in "ordering" prayer and hence knows that it is more effective than we realize.

But might God order "prayer" without causing it to be effective? If a small child prays for his rather strict teacher to die, would you expect that to be an effective prayer.?

My original question can maybe be reworded as: Can a  scientist  meaningfully use scientific methods (e.g .a double-blind trial) to test whether prayer actually is effective in reality as we experience it?

Best wishes

JIm

This isn't an answer but I am thinking about bird ringing and disease surveillance. It all hinges on the nature of the disease (or the prayer). I guess what you are implying is that it cannot be the case that the disease/prayer can be definitively marked as heard/cured at some moment in time (when it is treated/made) but may be later. (I pray for money to keep my aged granny and a year later she wins the pools. I suppose Go has quite a long "To Do List".) I do not know if there are diseases like this though. The bird ringing comes in because you'd need, at later points, to be able to tell (surveillance) to what extent people "found cured" had previously been ringed. (Maybe depression is an example, You get better before you get well and saying when you were fully well again is pretty hard and often retrospective.) If the quote is really about inscrutability (we will never know if x is the answer to a prayer) then I think it is untestable as stated. Or this could be complete bosh and not what you mean at all! Of course you do not really need bird rings, unambiguous identifiers would do fine (National Insurance Numbers?) but disease trials are usually heavily anonymised so this would go against the culture. You can tell I am thinking as I am writing but this might be an interesting question for educators. At the time the students may hate your lecture. 20 years on they may wish they had listened more carefully.

Edmund’s interesting and insightful post to this Q/A thread has prompted me to reread  Book V (the final Book) of Boethius’ very famous text “The Consolation of Philosophy” (written in Latin circa 524 -- I have  the 1969 translation by V E Watts)

In his final chapter Boethius tackles the perceived major difficulty that an omnipotent Supreme Being with total foreknowledge (as we typically assume) CANNOT grant free will to us. This is because everything that occurs must be set in advance (including our decisions) or it cannot be foreknown. Note foreknown not merely predicted.

In particular, meaningful PRAYER is impossible, it would seem, because, by assumption, the Supreme Being knows both the prayer and His/Her own response to it long before the times at which these two events occur. Hence there is no possibility of “free will” taking effect in the form of the prayer. This unattractive conclusion is clearly relevant to this Q/A thread.

Of course, Boethius argues against this conclusion.  As I understand his argument, he points out that the Supreme Being grasps the WHOLE of HISTORY, past, present and future, in one perceptual act so that free will IS possible (think about it!) and this  enables the meaningfulness of prayer.

The debate around this seeming problem (that foreknowledge is incompatible with free will) apparently goes back to Aristotle, Cicero, the NeoPlatonists, and St Augustine of Hippo amongst others. So “whole of history at a glance” argument is not original to Boethius, though perhaps his particular emphasis is.

If I have misrepresented Boethius or his argument here, someone please sort me out!

See also my RG Project: “Agents with Foreknowledge” which is of some slight relevance.

Best regards

Jim