Look, if the question is: Can people who use dowsing rods find items at greater than chance probabilities?
And the answer is clearly yes. HeXen’s grizzled old foreman is a clear example. People use dowsing rods of various sorts in various ways, and they are able to find all sorts of stuff.
And the next question is: what explains this ability?
The simple obvious answer is that successful dowsers usually have a lot of experience with the sorts of things they’re trying to find, and they use conscious and perhaps unconscious clues to make an educated guess about the location of what they’re trying to find, and the sticks or rods or pendulums are moved by the dowser even if the dowser is not consciously trying to move the device.
If there is some other phenomenon going on then what exactly that phenomenon is, and how it works must be discovered.
Is there some outside physical force that moves the stick or rod or pendulum? Or is it the dowser himself who moves the object, consciously or unconsciously?
Well, when we do experiments where the dowser knows where the object is–we put the object under 1 of 10 buckets as the dowser watches and ask the dowser where the object is, the stick or rod works perfectly to find the object. But when the dowser doesn’t see suddenly the rod doesn’t move by itself and the effect is much weaker, and it’s very hard to distinguish between the results and chance.
And so it is very reasonable to conclude that the dowser is the one that creates the motion of the stick, rod, or pendulum, or whatever. And this makes sense because there are so many physical methods of dowsing that all work differently but give the same result. Why would this mysterious force make one dowser feel a wooden stick pull downward, another see a pair of metal rods cross, another see a pendulum rotate counterclockwise instead of clockwise? And why is it that if we mount the stick or rod or pendulum on a platform suddenly this movement doesn’t happen, it only happens when a human being is able to touch the detector?
So they hypothesis that the movement of the detection device comes from the human operator is very well supported, and any alternative explanation would have to account for all these facts. Of course this doesn’t mean that something interesting isn’t going on, it just means that the feat is taking place in the human mind, not some electrical or mechanical phenomenon that makes the stick move.
And of course, the fact that dowsers often disagree about how dowsing works doesn’t mean it doesn’t work, it’s often the case that people are able to do a task but not being able to explain how or why they do it. It just means that we shouldn’t accept the theories of a particular dowser about their own abilities at face value, since they often disagree with each other. And of course there is the possibility that different methods of dowsing work in different ways.
So now that we’ve established that the movement of the detection device comes from the human dowser, consciously or unconsciously, what next? How are they able to use their minds to detect these objects?
And of course, it turns out that lots of people are able to use their minds to figure out where things are, even if they sometimes can’t explain or don’t understand why.
So take HeXen’s grizzled foreman buddy. He can go out in a field, walk around for a bit, and tell his team to dig over here, and he’s very often correct. Is that a surprising result? As HeXen said, it’s always some grizzled old experienced guy who does this, not the sensitive youngster.
So the decades of experience of the grizzled old foreman at locating stuff in his professional life turns out to achieve results much better than chance. And this is surprising?
And if we took that same old dowser, and instead of letting him walk around the job site and look and listen and smell and touch the clues about where the hidden object might be located, if we took him to a featureless test area where none of those clues exist and ask him to find the hidden object, what happens? It turns out that in tests like this the ability of dowsers to find hidden objects at greater than chance probability drops tremendously, to the point where it doesn’t seem like the ability exists at all.
So what are we left with? The astounding ability of people with a lot of experience in a particular task to accomplish that task without much in the way of obvious clues, and without being able to explain how their minds were able to make that educated guess. The fact that they use an apparatus that doesn’t work without the input of the human mind and body just means that’s the method they use to reveal the output, rather than just saying, “I think it’s over here”.
We see this sort of thing happen with other sorts of “apparatus”, like drug sniffing dogs. Line up ten people, give them each a sealed package, and one contains cannabis and the others contain chamomile. Ask a drug agent with a dog to find the package. And it turns out that when the dog handler knows where the package is, the dog will alert to that package much more frequently. And so we realize that the dog isn’t just alerting based on smell, but also by getting cues from the handler. If the handler thinks he knows where something suspicious is, the dog will alert even if the dog doesn’t smell anything, because the dog isn’t in the business of finding drugs, the dog is in the business of pleasing the handler. Does that mean the dogs are useless? No, the dogs really do detect some packages by smell. But the dogs are also a tool for the subconscious mind of the handler.
And so with dowsing, if anything else extraordinary is going on, before we can even start to explain it we’d have to show that something else is, in fact, going on. People can find things by using various clues, even if the clues aren’t obvious. As we remove all the clues, the ability vanishes. Therefore, the ability is the ability to interpret the clues. Any other theory of dowsing will have to explain this mountain of evidence better than the theory that people are smart and can figure stuff out from clues they aren’t even aware of sometimes.