I’ve taken a break from blogging because I haven’t felt the urge to write for a while. But just now I’m intrigued by the row about British water companies using ‘divining’ techniques. It’s the kind of thing that interests me: an example of the great gulf that exists between science and experience – or theory and practice – in matters of this kind.
It started when a couple in the Midlands needed to identify the path of the mains pipes near their home for a building project, and got the local water company to send a technician. They were surprised to see him walking around with ‘divining’ rods. As it happens, their daughter is an evolutionary biologist and blogger, Sally Le Page. She tweeted the company to ask what on earth it was thinking, using occult techniques when there is ‘zero evidence they work’. It tweeted back that in fact it finds some of the older methods are just as effective as the new ones, although it also uses drones and satellites.
This got someone else hot and bothered, and he contacted his local water company, which confirmed that yes, some of its technicians still used dowsing rods when they needed to. Le Page then tweeted the UK’s other water companies, and most of them said the same. A total of ten out of twelve confirmed that they use dowsing.
All this then got into the mainstream press. I first saw it in the Guardian, which has now run several pieces, essentially crying ‘witchcraft!’ As with homeopathy, the outrage is about people resorting to superstitious practices, along with high-minded complaints about wasting taxpayers money, risking damage to lives and property, and so on.
The water companies naturally took fright, and ordered their PR people to do an about-turn. As a result, some companies now say they don’t actually equip their technicians with dowsing rods, but they understand some use them on their own initiative. Others have decided they disapprove of the practice, and blame ‘rogue engineers’.
As it happens, I went into this subject recently when the Psi Encyclopedia (which I edit) uploaded an entry on dowsing, the preferred term to ‘divining’, as its author points out. The article mentioned some interesting evidence in its favour, but didn’t give much detail, so I expanded it somewhat, and in view of the current brouhaha I now think it should be presented in much more depth in a separate entry. It comes in two lengthy articles by a German geophysicist named Hans-Dieter Betz, published in the Journal of Scientific Exploration in 1995.
Betz starts by describing a 1980s water-drilling project in Sri Lanka carried out by a German development agency, Deutsche Gesellschaft fur Technische Zusammenarbeit (GTZ), and funded by the German government. Using conventional methods to locate potable water sources for rural communities in Third World countries is time-consuming and costly, especially as they often come to nothing. This applied here, where the aim was to provide drinking water for the town of Vavuniya and poor rural villages in the north of the island. So the project manager, Hans Schröter, used dowsing techniques to identify promising sites, and in most cases drilling revealed usable water strata that, it’s claimed, could not have been identified by means of conventional geo-electrical measurements.
The value of this result has to be highly appreciated: in a terrain largely unknown from a hydrogeological point of view, proving to be particularly difficult on account of its principally crystalline bedrock of variable and mostly light fracture intensity, 654 wells have been successfully constructed within a short time and without any noteworthy precursory studies, partly under very difficult imposed conditions, and with a small staff and two relatively simple and medium-capacity rigs… Within the final evaluation of the entire program, only 27 of the 691 drillings can be considered as classical dry holes; that constitutes a failure rate of 4%. Not only for that particular area, a success rate of 96% must be considered as being untypically high; no prospecting area with comparable sub-soil conditions is known where such outstanding results have ever been attained.
But was Schröter’s dowsing really the cause of this success? To try to find out, GTZ carried out a simple field experiment near Vavuniya. Two bore holes had been drilled in a school yard by in a separate project funded by Norway; both turned out to be dry. GTZ asked Schröter to dowse for alternatives in the same area. There was no vegetation, and no other visual clues to enable intelligent guessing, as confirmed by sceptical hydrologists. Betz writes:
After a short time, Schröter found, thanks to his subjective dowsing reaction, a place where he supposed that drinking water could be found at a depth of as low as 35m and with a yield of at least 10 l/minute. The allegedly productive spot was located some 30m from the one and 80m from the other dry borehole. A light mobile drilling rig could immediately carry out the test drilling and finished it by dawn of the same day. The result was unequivocal: water was found just as predicted. In this case, the value of the dowsing technique was confirmed, regarding not only the location but, to general surprise, also the depth and deliverable water quantity.
In a second test, Schröter was asked to reverse the process and identify a dry site near to a successful borehole, one that would yield less than 5 litres per minute at a comparable depth, ie 50 metres. Drilling at the site he indicated produced water at 13 litres per minute near the surface, but none in the hard rock below, which was the target area. (Betz makes the point that skilled dowsers seem able to distinguish the depths at which water can be found.)
In a third test, in rural villages in Sri Lanka, a direct comparison was made between conventional methods and dowsing. The aim was to identify drilling sites in a particular area that would provide at least 100 litres of water per minute. Fourteen sites were identified by conventional methods – mainly geo-electrical procedures, supplemented by the study of geological maps and aerial photographs, and information supplied by local experts based on previous explorations. This took several weeks of intensive work. Schröter was then asked to inspect the same area and identify drilling sites by dowsing alone, without benefiting from any of the available data. Within a few days he had come up with seven positions.
Drilling then began on all 21 sites, carried out by the same team using the same equipment and to the same depth. Of the fourteen sites identified by conventional methods, three were found to be above the target, producing 300-400 litres per minute; the rest were below. Of the seven identified by Schröter by dowsing alone, six were above the target (150-400 l/m); one was below.
For practical purposes, this was a clear win for dowsing over conventional methods – 86% compared with 21% - and you can see why GTZ were so keen to persevere with it. (Betz goes on to point out that the company’s success was far greater than that achieved by a Norwegian company in the same area a couple of years earlier.) The rest of his first paper documents similarly successful activity involving dowsing in other countries: the Philippines, Dominican Republic, Congo, Niger, Yemen, Verde Island, Kenya, Egypt and Namibia.
In his second paper Betz describes three other high performing dowsers in Germany (briefly summarised in the Psi Encyclopedia article). He goes on to report in detail on two scientific studies which he carried out at Munich’s Ludwig-Maximilian’s University, with Schröter among the subjects. One was in a barn, and involved trying to trace the path of concealed water pipes. Most of the subjects performed at chance, although there were significant results in a few cases, but nothing spectacular. A second similar experiment was carried out outside in fields. Here too the results were poor in most cases, but highly significant in a few (naturally including Schröter).
The first of these experiments was scrutinised by Jim Enright, a sceptical behavioural physiologist. Enright rejigged the stats used by Betz in order to get an insignificant result, and larded his piece with the usual sort of polemic to drive home his point, reassuring those who feel insulted by the idea that something as crazy as dowsing might actually work. In his rebuttal, Betz rejected Enright’s cleaned up stats as ‘crude and illegitimate’, which Enright in his turn dismissed ‘feeble’.
As is often the case in these sorts of quarrels, I have no idea who’s in the right – once researchers start fighting over stats, it’s hard to follow. Of course there’s a history of sceptics doing this to discredit findings they don’t like, and there have been notable instances when professional statisticians have sided with the researchers. I’m also curious about the earlier ‘failed studies’ listed on Wikipedia. As Guy Lyon Playfair points out in his book on twin telepathy, early, supposedly negative experiments in that area were found to be positive on later reinterpretations, and here it would be interesting to know how the research was carried out, with what assumptions, and so on.
But as far as I can tell – and I still feel woefully uninformed on this topic –the large-scale double blind experiments in controlled conditions that would validate dowsing to doubters just don’t exist. So I can’t blame the critics for being snooty about it. At the same time, there does seem to be at least some evidence that dowsing works in real-life situations. Clearly, the phenomenon applies to certain gifted people, and therefore isn’t likely to show up in controlled studies carried out with multiple subjects. But in that case, I wonder, if something like dowsing really is true, how would we know?
One way is simply to trust the experts, which brings us back the water companies, and their (initial) airy admission that some of their engineers use dowsing because it works. They get results from it. The technician who was seen using ‘divining rods’ to find buried water pipes presumably did so because it had worked on previous occasions, and at least was worth a try. There’s a strong business rationale, too, if it means getting a quick result with a minimum of expense, in what is a costly and time-consuming activity.
In a situation like this, it seems to me, something that works, and that saves time and money, is at risk of being prohibited because of the prejudices of a few people, who rage against the idea of solutions being applied for which they can think of no conceivable explanation. If it really was down to guesswork and subconscious clues, as they argue, it surely wouldn’t be adopted in professional situations.
This dynamic is repeated over and over in different contexts. US government security agencies in the Star Gate program didn’t keep spending money on remote viewing in the hope that it might help them find bad guys, locate enemy activity, release hostages, and so on, but because it actually did so. It’s also why some detectives sometimes work informally with psychics, because it gives them leads and helps them locate bodies. Businesses use dowsing to find oil and minerals. They don’t need to know how it works, or take fright at the lack of a meaningful theory, or the absence of validation by controlled double blind studies. They’re driven by profit and just get on with it
None of this interests sceptical scientists, who focus on their own agenda as evolutionary psychologists, behavioural physiologists or whatever. But surely if they started to ask why some professionals persist in ‘superstitious practices’, with genuine interest – and listened to the answers – some meaningful science might eventually come out of it.