Archaeological Dowsing IV – Revenge of the Rods


Emmeline thought the “Ideomotor” must be some newfangled form of transport…


I’ve written before about the limited (but still too widespread!) acceptance of dowsing in archaeology on several occasions. Needless to say it hasn’t gone away since then. As dowsers are all too fond of telling us, it’s an “ancient” technique. I recently became aware of an attempt by  a group of amateur archaeologists convinced of its efficacy to win over their professional colleagues and raise public awareness. You can read it here.

The most superficially impressive claim therein is this;

“[Paul Daw’s] discovery, by dowsing, of anomalies between the stones in the Stanton Drew circle, Somerset, prior to their detection by fluxgate gradiometry, merited a brief note in the magazine British Archaeology, No. 111 (March-April 2010)”

This wouldn’t be the first time that non-academic archaeological publications have uncritically reported dowsing, but I wanted to investigate this further. The note in question is entitled “Geophysics finds encourage new look at Stanton Drew” and the relevant paragraph reads;

“[The archaeologists] found anomalies between the stones of the circle, which John Oswin and John Richards (BACAS) and Sermon suggest may be contemporary features. Though not revealed before by geophysics, similar features had been claimed earlier in the year by dowser Paul Daw.”

There is a subtle but important difference here. The claim implies a match between anomalies “discovered” by the dowser and those actually found by geophysical survey. In fact nothing is said about just how “similar” they were, nor how precise a match they were to the dowser’s features. Just that “similar features” had been claimed.

Now, a stone circle, oddly enough, consists of one or more circles of, er, stones. Stones require holes in the ground in order to set them. Several thousand years often leads to stones being removed, relocated, or destroyed. Thus there is a pretty good chance of finding some sort of buried hole in the ground in between those holes in the ground that are still obviously filled with stone. One can also take a pretty good guess at the likely size of any as-yet undiscovered holes in the ground based upon said above-ground stones. Finally, stones in stone circles are usually spaced in an even manner, further increasing the chances of correctly guessing the location new features. The upshot of all this is that unless we can know how closely Daw’s plotted holes matched those found by science, the claim is worthless. This is the closest thing to independent assessment of this society’s efforts that’s offered. Everything else is self-claimed and self-affirmed (as with the “test” linked in the closing paragraph of the newsletter).

The rest of the newsletter consists mainly of claims to have discovered or confirmed the suspected routes of stretches of Roman road (and features connected to them) in the area. Most are unfalsifiable, and to be fair, without professional backing dowsers often lack the means to “verify” their own work. One claims to have been cited by (presumably) an archaeologist;

“Interestingly, just a few months ago, Judy and I attended a lecture on ‘Roman Roads in Cumbria’ by a man we’d never met, and were amused to learn that ‘Andrews and Andrews’ are now officially credited with the discovery of the Kendal to Ambleside Roman route – even if we did use dowsing to find it!”

The big problem here applies to the other supposed success stories in this newsletter. These people may well have discovered a stretch of Roman road, but the extent to which they used dowsing to do so is far from clear. In fact like the other contributors, it is clear that their achievement relates to their fieldwork methodology as a whole including visual survey (simple observation of the lie of the land), field survey (measuring it with trundle wheels, ranging rods, perhaps even theodolites in order to detect changes in topography) placename research (settlement and feature names known or suspected to denote a former Roman road in the landscape), map work (using maps to determine likely routes based on contour lines, watercourses etc) and a bit of local knowledge to speed things up. Together with confirmatory excavation, this is how such features are found. We need to know precisely how the dowsing was done, and what aspects of the find it supposedly contributed to. Naturally I suspect that it played no part.

To be fair, being a local archaeological society, funding and opportunity for excavation is going to be limited, hence these guys aren’t often going to be able to confirm their fieldwork (dowsing or otherwise). Hence on page 7;

“Our results were vindicated when a gas pipeline subsequently cut across the line of this road and revealed a cobbled surface complete with two Roman hobnails on exactly the same alignment as that determined by dowsing (Wilson, 2009: 288)”.

Again, we are expected to take their word for this – the word “exactly” is not quantified. I realise that this is only a newsletter and not a journal article, but if the goal is to lure more “conventional” archaeologists into the fold, surely something other than bald assertion will be needed. A nice diagram of coinciding datapoints, perchance?

I realise you’re trying to attract paying members in order to keep your heads above water guys, but how about at least a sneak preview of any data that might actually lie hidden in a copy of your journal, archived in the basement of the local library and labelled “beware of the leopard”? Of course even some impressive-looking results would still need to be subject to peer review and then reliably replicated before we could all burn our magnetometers. It doesn’t matter how cheap and easy dowsing is if it does no better than chance.

So, though working somewhat in the dark, it seems to me that these chaps are checking existing lines along which roads are suspected to run. Roman roads are (famously) linear, but tend to respect the existing topography (at the time). So it should be no surprise that dowsers are able to plot a fairly straight route vaguely in the same alignment using nothing more than pre-existing knowledge and educated guesswork, mediated by the ideomotor effect. Without knowing how close a match they got, or how many “misses” they made, we can’t begin to assess whether dowsing has played a meaningful part. Quite apart from it having no currently conceivable mechanism behind it.

Now, if excavation confirmed a stretch of road “found” wholesale by dowsers without any prior evidence that there was one there – that would be more impressive. But you would need to undertake some sort of initial survey to find a place in which to begin looking. As a result there would still be a percentage chance of finding something, and so we would still need to know how many attempts were needed before gold was struck, as it were. It also wouldn’t be fair to expect a dowser to just go and find a road, because even a geophysicist would struggle without some kind of lead. The only fair way to test is a with a tailor-made and agreed blinded protocol, where there is definitely something there to be found, and the only means of doing so is by dowsing. Like this, for example.

In summary then, this newsletter presents strictly anecdotal evidence of a technique that is very difficult to separate from others that by necessity must be used when in the field. It’s never going to be able to persuade any critically thinking archaeologist that dowsing is worth looking at.

Guys, if you’re sincere and interested in evidence, even when it doesn’t work out in your favour, why not construct a proper test and publish the results in a future issue? Or at least give us enough information about your fieldwork “successes” to let us think for ourselves about them.


Archaeological Dowsing (Part Three) or ‘Dead and Buried?’

gravestoneIt might be ‘fringe’, but I doubt it will ever truly die…

Forgive me if I appear to beating a dead horse, but I feel vindicated in posting this last instalment by this recent article. It contains the usual anecdotes,  and absolutely nothing to suggest that the same old mix of ideomotor effect and educated guesswork isn’t also at work here. See the JREF forum for some discussion. Suffice to say that there is just no evidence to support the dowser’s claims to be able to precisely locate grave cuts.

Anyway, I promised in Part II (Part I is here) to dissect the one readily-accessible ‘study’ of archaeological dowsing cited in the recent pro-dowsing article in ‘Time and Mind’ journal. So here we go…

I tend to draw a parallel with another deluded group of people that think they can divine special information – ‘psychics’. In this case it seems to me that, like a psychic with semi-conscious prior knowledge of a client, the dowsers here knew roughly what types (and sizes) of structure they were looking for, and approximately where they ought to be. They also started from visible features above ground. Despite these advantages, the results remain far from impressive. The final dowsing survey, by the author’s own admission, varies considerably from the true layout of the structures. How is it possible to divine roughly the right shape, yet have it be metres out of place? Do the rods need calibrating?

If you’re trying to make sense of the plot yourself, you should note all the many instances in which red lines seem to overlie existing features on the map – this is because surface features not discovered via dowsing are for some reason still included in the ‘dowsing’ overlay, along with other features known archaeologically – like the cellar and tower base – also not surveyed by dowsing. For comparison of dowsing results with reality, this basically leaves the chapel – which is nevertheless known to exist on the site. Further, it is a type of structure well known (archaeologically and colloquially) to appear as a simple rectangular structure aligned east-west, often with an apse at the east end. Nor can we by any means discount prior knowledge of this particular structre. The approximate size of the building appears in the historical record, and the excavations that uncovered the chapel were done many years beforehand, qualifying the claim that the dowser’s “ all came before the excavations..”, which must refer to the most recent round of digging. The site of the building is even marked on Ordnance Survey maps, including a Victorian map that the author shows in his own report. Even without this information to hand to refer to, the surface features surrounding the area really don’t give much room for maneouvre, making the chances of placing this east-west oriented rectangle of known size somewhat accurately into this constrained area actually fairly high. Despite all of these advantages, by the author’s own admission the accuracy of the divined features ‘is poor’. Rather than the technique perhaps being at fault, this is blamed upon the subsequent mapping process. As for the ‘correct disposition’ claimed – we’ve already seen how the chapel plot might resemble sub-surface remains – but as no dimensions are given for the dowsed plot, we can’t even be sure that compare the level of precision in the plotting of the walls. Finally, the chapel itself contains a number of gravecuts, as one would expect – but are they really that close a match for the excavated graves? There are so many that hits are almost inevitable – and why the discrepancies (e.g. no tightly-spaced second row of graves, some out of place, others not even plotted)? And what of the distinctive apse plotted by the dowser? Bzzzt, wrong. There’s a pile of debris that could once have been an apse, but why would the dowser show up an intact apse rather than a pile of rubble?

I should stress that there is no question here of an intent to deceive – most of this information is presented by the author of the report himself. In fact, some of the worst failures in accuracy, or even missing some pretty substantial features entirely, are included in the report (and further undermine it). The author is simply placing too much weight on the results that can be rationalised as hits – presumably because of wishful thinking. But these hits are highly subjective in the interpretation. For example – how close a match do you think this culvert plot actually is? What of the features revealed by geophysics that don’t line up? Once again – pointing out ‘hits’ whilst ignoring the misses, also known as ‘observational selection‘ just like a psychic reading or an observation that the full moon affects violent behaviour.

The same report also includes a ‘test survey‘ that one might hope would be a controlled, blinded scientific study, but actually amounts to a subjective survey of the experience of dowsing, with no quantification or qualification of any successes had. The ‘positive results’ amount to an aggregated and near-random scatter of points – and again a good deal of faith is required to match any clusters of points with real features. If you were to draw a new plot of imaginary features and overlay that on top of the same scatter, you would still find ‘correlations’. It is nothing more than a ‘join the dots‘ game. And at the risk of poisoning the well somewhat, despite the citing of this study by the Time and Mind article, note the inclusion of Test 5, intended to “locate their own body field which is normally at about 450mm”. There is no evidence whatever for (and a few laws of physics against) the existence of such an ‘aura‘. Hard science, this ain’t.

As an aside however, I would like to give full credit to the author of that report for debunking what is a myth even within dowsing circles – that dowsing is depicted in the cave paintings at Tassili nAjjer in the Sahara. It isn’t – the figures are patently archers.

Archaeological Dowsing (Part Two) – ‘Non-Sense of Place’

sentaidowseThe future of archaeology?

As promised – the second part of my article about dowsing in archaeology (first part here). This week, we’re bang up to date with the latest ‘research’…

A recent article in the fringe journal ‘Time and Mind’ (behind a paywall and with a stupidly long title) included a section in support of dowsing as part of a supposedly emergent approach called ‘Spirit of Place‘, borrowed from ‘psychogeography‘. Right away, a flaw becomes apparent. Psychogeography is only valid (insofar as it is!) because it deals with what people we can actually talk to – who are alive today – are thinking about the place they’re in. Archaeology is about dead people. The difficulties here should be apparent!

The authors wish to graft this onto a little-known but pre-existing discipline called ‘archaeography’ – originally defined as a scientific, documentary-based parallel to field archaeology of the historical period (though colloquially, it has a portmanteau meaning of archaeological photography!). In contrast, ‘Spirit of Place’ is an attempt to reconstruct the psychological ‘feel’ of a site (including prehistory) along the lines of the post-modernist field of phenomenology, using such approaches as archaeoacoustics, lighting effects, temperature, weather and even feelings of foreboding. Not quite paranormal stuff (more psychology and art-based), but pretty speculative and subjective. The whole idea seems to be a perverse reaction to the realisation that archaeology has relatively little to tell us for sure – this kind of thing seems to me to be throwing baby out with bathwater though. A licence to make things up doesn’t ‘fix’ the problems with traditional archaeology – it compounds them, adds to confusion, and validates those in the new age fringe that have quietly championed such approaches for years, albeit for religious/spiritual rather than epistemological reasons.

Back to dowsing though, which is the initial focus of the piece. The piece acknowledges the existence of criticism by professional archaeologists (the authors being in fact a business analyst and a complementary therapist respectively), but instantly dismisses it;

“..others have been scathingly dismissive (Williamson and Bellamy 1983), though sometimes perhaps more from prejudice than practical experience.”

‘Practical experience’ has its many uses, but falsifying a scientific method is not one of them. Again – if the aim is to establish whether dowsing works AT ALL, properly controlled tests would make that experience utterly irrelevant. In fact, when we look up the bibliographic reference given, we find that the book (a debunking of another ‘woo’ idea in archaeology – ‘ley lines’) for some reason conceded that;

“No doubt it is possible to dowse for buried water,..”

Assuming (correctly) that ley lines do not exist, and that archaeological dowsing is contingent upon that, it then proceeded to dispose of this in a two-for-one deal;

“.. but when the search is for ‘earth currents’ the process becomes far more subjective.”

This was therefore a pretty questionable example of criticism to choose, as it takes for granted that dowsing in general terms is valid, and only quibbles with its application in archaeology. It is therefore easily dismissed as ‘prejudice’. Having seen off their carefully-chosen opponents, The Time and Mind article authors, in common with many proponents, therefore proceed under precisely the same lazy assumption – that water-dowsing is in any way proven. Also typical of pro pieces is that the bulk of the evidence offered is anecdotal (more on this later) or at best, what (arch-enemy of Dowsing) Vogt calls ‘field tests‘ (as opposed to scientific tests) prone to all sorts of misleading results. Where this article differs slightly is in this string of apparently academic bibliographic references;

“…a Roman fort and Tudor culvert beneath the site of Kensington Barracks (Bell 1947); Iron Age defensive ditches at Mellor hill-fort (Andrews 2007); Roman roads in Lancashire (Plummer 1976) and Essex (Ingram 2007); and medieval farm buildings at Cressing Temple (Hillman-Crouch 1999).”

Impressive, no? ‘No’ is right. ALL but one of these are from the same source – the Journal of the British Society of Dowsers – hardly scientific, not even peer-reviewed – fringe publications. They are also not accessible online (though neither are most proper journals), and tough to find even in the real world. I did however come across this amusingly scathing review of an anthology of BSD articles (edited by one of the Time and Mind co-authors!) that does appear to include Kensington Barracks article (or at least another about the same site). My favourite quote has to be;

“This kind of nonsense would normally hardly merit a review in any respectable journal.”

This is very true, and rightly so. At the same time, this kind of passive disdain by academics can make it all the easier for the unwary archaeologist to fall for the charms of the technique. Fortunate then that this reviewer decided after all that some attention should be devoted to it. Needless to say, I wholly agree with him on both counts.

The final quoted source is an online-only self-publication of sorts – an earnestly written report into dowsing at Cressing Temple Barns in Essex. It’s the only one that we can access with any degree of ease, and it’s an excellent case study in the sort of well-intentioned but wrong-headed approach that leads to people being convinced that dowsing (of any flavour) actually works. I’ll take a look at this in detail as a final part to this series next week.

Back to the Time and Mind piece, as in bass-ackwards fashion it attempts to explain how such ‘results’ are obtained;

“As for how it works, the various scientific studies over the past century all seem to indicate that no single mechanism is involved (Barrett and Besterman 1926; Maby and Franklin 1939; Tromp 1949; Maby 1966).”

None of these are ‘scientific studies’ by any reasonable definition, and what they indicate (by their disagreement) is not that more than one mechanism is required to explain the phenomenon, but that the phenomenon does not actually exist! .

“Instead, it seems more likely that a “weighted sum” is derived from multiple perceptual mechanisms, akin to pattern-recognition in neural networks (Bishop 1995). What is also clear from the studies is that, despite appearances and the users’ impressions, the instrument moves only because the hand moves in response to a nervous impulse arising from that “weighted sum;” and the response conforms to that of a mediated or semi-voluntary learned reflex.”

Aside from the pseudoscientific techno-babble, this is very telling, as it eschews the usual external explanation – that the sticks move by some ‘energy’ unknown to science – in favour of something completely indistinguishable from the usual sceptical explanation for dowsing – ideomotor effect. And bearing that explanation in mind, I think it’s telling that the article claims that;

“A solid grounding in archaeology is definitely advantageous; to paraphrase Louis Pasteur; dowsing may at first appear to be chance, but such “chance” favors the prepared mind.” In this it resembles the practical skills required in fieldwalking surveys; an experienced fieldwalker would have little difficulty in distinguishing between fragments of chert and flint, for example, while the “untutored eye” will struggle to identify anything. In short, the quality of results will depend on the skill, experience, and background of the dowser; and discipline is essential.”

Except that fieldwalking is a visual survey method to which an experienced ‘eye’ can be applied – and the eye as a sensing organ is pretty well documented! Whereas dowsing is supposedly about sensing hidden features using some unknown organ or aspect of the mind. This analogy pre-supposes that it’s even possible to detect anything. Nor does the article give any evidence for the untrained dowser actually being any less adept at achieving good results than the so-called ‘expert’. The only difference is likely to be that the ‘pro’ will make many more dowsing pronouncements, and so end up with more ‘hits’ – like a psychic making regular predictions in order to secure that one impressive result for her website.

We’ve already seen that few professional archaeologists actually believe in dowsing, and even fewer actually seek it out as a technique. The only people pushing it are the new agers, certain of the subject-enthusiasts, and now these ‘archaeographers’. But strip away the post-modernist trappings, and what’s left? Imagination, questionable use of psychology, ‘conversation with place’ and;

a ‘belief in a ‘Spirit of Place’ that [is] held as if true, which is not the same thing as saying that it is true’.

So in fact the information being gathered isn’t actually real? Is that really any more use to anybody than new age feel-good religion and its own associated tracts of word-salad? I wonder whether ‘Spirit of Place’ – especially archaeological dowsing – isn’t just an attempt to legitimise fringe practices by creating a new discipline not bound by the same rules and conventions as field archaeology or archaeological science. Dowsing even crops up again at the end of the article, in the form of a bizarre psychic fieldwalking exercise guided by dowsing rods and attempts to ‘talk’ to the monument. Quite what this is hoped to achieve is even less clear than the ‘conventional’ usage already described. Given the spiritual overtones, emphasis on ‘feelings’ rather than facts, and employment of otherwise-questionable techniques like dowsing, isn’t this simply the New Age in a tuxedo (or perhaps a tweed jacket with elbow patches)?

So much for the latest reinvention of this old chestnut. Essentially, the reason archaeological dowsing is bunk is the same as applies to all other dowsing – there are no scientific tests to support it, no scientific method by which it could work, and the ‘results’ it obtains are better explained by the ideomotor effect and perhaps a measure of educated guesswork. Where excavation seems to confirm a dowsing survey, to eliminate other more parsimonious explanations we would need to keep track of the ‘hit’ rate. In other words, what proportion of dowsing pronouncements actually result in a find? For every Roman fort, how many follow-up excavations or remote sensing surveys fail to locate what was suggested – and how many fail to find anything at all? Otherwise, we are counting the hits and ignoring the misses, just like a ‘psychic’ reading. No matter how often the authors insist that dowsing and ‘Sense of Place’ should never replace scientific methods but instead complement them, there’s no evidence that they’re of any objective use whatever.

I’ll end with a quote from my new hero, the author of that ‘Antiquity’ piece…
“I do feel very strongly that archaeology is already lumbered with far too much lunatic fringe – mostly born out of ignorance of the natural sciences; and that this sort of pernicious nonsense can serve no purpose other than to increase confusion.

…and a reminder that any archaeological/graphical (or for that matter, any other dowser) still stands to win one million dollars if they can show results better than chance under agreed controlled conditions. What’s your excuse?

Archaeological Dowsing (Part One) – Divining Bad Archaeology

indyIndy was never without his dowsing rods.

Archaeology has a tremendous amount to offer us all – at least as much as history as a discipline – and is in many ways more accessible and more exciting. However, it’s my impression that as a younger discipline with radical roots and romantic baggage, it remains rather vulnerable to speculation, assumption of facts not in evidence, and the embracing of what is known in sceptical circles as “woo“. The New Age has a lot to answer for, and some of the same hippy types and left-of-field thinkers that make archaeology so vibrant as a field can also inadvertantly do it down. Notable amongst the techniques and approaches adopted by some archaeologists of that era is archaeological dowsing.

The first part of this article explains why it is actually entirely bogus, and attempts to explain its popularity regardless of this. Part two covers the most recent attempt by proponents to rehabilitate dowsing in archaeology by defining a role for it on the periphery of the field – potentially adding to public and media confusion and perhaps even leading a new generation of archaeologists to believe that it is a legitimate technique.

Allow me to put it bluntly. Dowsing – the detection of water or buried objects and features (in this case archaeological ones) by the human body via a stick, pair of rods or a pendulum – is bollocks. Not one properly controlled, blinded (i.e. scope for bias of both experimenter and dowser eliminated) trial has ever shown it to perform better than chance – and crucially – any positive results have not been repeatable. This means that the successes, the ‘hits’ if you will, are a mixture of pure luck and some other factors that I will come to later. And yet, unware or unfazed by this fact, people still buy into it – including those involved in archaeology.

A survey reported in American Antiquity in 1984 showed that teachers of the subject were much more likely to both cover archaeological dowsing in class, and to put it in a positive light, than they were other “fringe” ideas including Bigfoot, Noah’s Ark, ancient astronauts, and psychic archaeology. Yet none of these are accepted by science as legitimate subjects of study, and all have the same low quantity/quality of evidence to support them. In my younger days, I too was taught that it was a valid, if less effective, technique when compared with geophysical survey methods. I swallowed this uncritically for many years until set straight by a sceptic. And it wasn’t just one kooky tutor.

One of my old course books for archaeology students in the UK, Greene’s ‘Archaeology: An Introduction’, lists dowsing along with legitimate scientific techniques like ground-penetrating radar and geophysical survey. The author cites his own personal experience of seeing it ‘work’ at a South Devon site – even though he makes clear that the dowsing farmer in question had already observed the feature as a crop-mark. How hard can it have been to then ‘locate it’ using a forked stick? Interestingly the updated edition seems to have excised the section on dowsing. The archaeology student’s bible, ‘Archaeology: Theories Methods and Practice’ has a commendably open-minded mention of the practice, noting anecdotal success but stressing that most do not believe in it and that the evidence thus far is wanting. This is more open-minded than I personally think it deserves – like the search for ESP, the evidence has not improved since the first half of the 20th century. And in fact the up-to-date edition again seems to have backed away even from this already sceptical position – as it includes a reference to a thorough demolition of the ‘technique’ written after my own copy was published.

This cautious acceptance of dowsing in the literature has come from individuals within the field who championed its use, especially in the first half of the 20th century. Wind the clock back fifty years, and you will find archaeologists like T.C. Lethbridge, who was admittedly more an antiquarian museum keeper than a field archaeologist in the modern mould (and not, as the National Trust recently claimed, a PhD). Dowsers today would like to abstract dowsing from its occult context – Lethbridge clearly saw it as part of the magical realm.  Probably the earliest legitimising source is R.J.C. Atkinson’s ‘Field Archaeology’, published in 1953.

As science turned its attention to dowsing, the climate became less conducive to such endorsements, but as post-processualism and post-modernism set emerged in the 1960s, dowsing was able to keep its head above water, for example this 1967 quote from Ivor Noel Hume;

“… archaeological dowsing has been tested under all sorts of conditions and there remains no doubt that two pieces of wire, each bent at a right angle and held lightly in each hand, will cross when they pass over metal.”

The early 1980s witnessed a second boost for archaeo-dowsing in Britain with the publication of a new field manual by the father of wetland archaeology, Dr John Coles. At this time individual archaeological units even made use of it, for example York Archaeological Trust who in 1983 reported their employment of a dowser in a published monograph (p.47). Today archaeological dowsing has mostly returned to the periphery, largely ignored by the mainstream of the profession, but it could once again be on the up. Not just enthusiasts but also a number of professional archaeologists continue to set store by it, to varying degrees. Most notably, Prof. Timothy Darvill of Stonehenge fame recently reaffirmed his belief in it to the author of a new article on the subject – though Darvill also embraces some other ‘interesting’ neo-antiquarian approaches, as the Counterknowledge link (and a post of mine) demonstrates. Dowsers are still permitted to involve themselves with archaeological sites (though they may no longer appear in excavation reports). The rationale is no doubt that their services are free and harmless – but if their results inform later excavation, money has been wasted. In terms of the heritage/visitor attraction side of archaeology, even the English National Trust recently published an article (see page 60 here) affirming that it;

“…has many practical, if seldom publicly credited, uses” and that “the National Trust … has, unofficially, been putting it to use for some years”

The author has simply bought the dowsers’ propaganda rod, wrist, and forearm. Incidentally, I challenge anyone to come up with evidence of dowsers being employed by utility companies, and especially by the police.

Local archaeological societies, in the best traditions of their amateur antiquarian forebears, are also liable to dabble in dowsing, just as dowsers are wont to dabble in archaeology. Today, you can even go on a course to learn to dowse for archaeological features, and the various National Trust properties mentioned in the above-linked article also offer ‘workshops’ in it. I’m personally aware of one national museum that employed a dowser, and less well-funded sites take advantage of the low cost and high level of mystique associated with putting on dowsing events at their museums. Finally, like other questionable aspects of archaeology, it maintains a public profile via the media, including several appearances on Channel 4’s Time Team, though to their credit they outline its failure to date and remain sceptical.

There remains a lack of engagement by archaeologists with the subject of dowsing, whether pro or con, few seem interested in actually testing it or analysing its claims. Those criticisms that exist are sometimes cautious – a lack of reliable results making archaeologists suspicious or even cynical about dowsing, but not necessarily truly sceptical. Clark’s benchmark book on remote sensing in archaeology bemoans a lack of data, but also ends up adopting a circumspect “it’s probably bollocks but let’s not offend our more eccentric colleagues” attitude. Colleagues in the more scientific disciplines of the field appear bemused and dismissive – understandable when you consider that it’s those without a grounding in the sciences who are most prone to drink the dowsing Kool-Aid – but though well-placed to look into the technique, they instead steer clear. Even the Institute of Field Archaeologists, who go so far as to recommend against using it, don’t go into any detail. This seems strange given the wealth of sceptical literature on the subject in general – even in the popular press.

Luckily, there are a handful of truly sceptical articles to be read. For British archaeology, Hancock’s ‘Dowsing the Rollrights‘ is interesting because it tackles dowsing from its most convincing aspect – personal experience, and still comes away unconvinced. The most comprehensive debunking out there is Van Leusen’s ‘Dowsing and Archaeology‘ from the journal of Archaeological Prospection, later reprinted in Skeptical Inquirer magazine. It summarises the literature, and focuses upon the book ‘Dowsing and Church Archaeology’ – held up as the best evidence available, but as this article makes clear, actually incredibly flimsy and open to interpretation. The abstract says it all;

Both among the general public and among archaeologists there is a widespread belief in the presumed abilities of dowsers to locate underground archaeological features. This article reviews the nature of such beliefs as evidenced in published materials from professional archaeologists in the UK. It is found that there is a contradiction between largely privately held convictions that dowsing works and public rejection, caution or silence. An examination of the best available published evidence for the validity of dowsing shows that field tests were badly designed and executed, ignoring important statistical biases and modifying test parameters in order to obtain positive results. These methodological shortcomings are traced to archaeologists’ lack of training in controlled test design, and prior belief in the validity of dowsing. Where field tests were properly designed and executed, no evidence for the validity of dowsing was obtained. The article concludes that properly designed tests are entirely feasible, and that it is up to the proponents of dowsing to conduct such tests.

It’s the same story in the US, where the State Archeologist for Iowa has online another very sound and even-handed review of the literature that nevertheless doesn’t end well for the dowsers. So if you feel my own tone is too dismissive and sarcastic, please do have a look at these sober pieces, which despite the damning evidence, still retain the proverbial ‘open mind’ to any future, properly designed testing.

So if most archaeologists agree with their professional body in not setting store by dowsing, why this reluctance by others to consign dowsing to the loony bin of archaeology? Well, dowsing is superficially plausible, especially if you’ve seen it done or, given how little it costs to try and the reliably impressive physiological mechanism by which it ‘works’ (more on this later) – if you’ve experienced it yourself. Even without this ‘easy sell’ if, like me a few years ago, you haven’t actually given it much thought and don’t have a grounding in the sciences, it still seems like something that could work. See this clip from a Scottish archaeological programme in which the presenter is amazed by the apparent response of the rods, yet when a trench is cut, nothing but clay is found.

Crucially, dowsing also doesn’t require an overtly paranormal mechanism – no ghosts, aliens, or even ley lines required (though the latter are often invoked, along with even weirder notions). It also carries with it a great deal of anecdotal evidence – given a great deal of credence by people informally weighing up everyday claims, but actually worthless when it comes to such scientifically falsifiable (and laws-of-physics-defying) claims as this. Another factor is that most people – no matter how intelligent and highly educated – are not scientists, and field, academic, museum, and theoretical archaeologists aren’t either. They are what Dr Ben Goldacre of calls “humanities graduates”. Clever, knowledgeable, but not familiar with even the most basic scientific method. So if those sticks move without your conscious effort, it must be some magnetism or something, right? Makes sense. More importantly though, most people (and archaeologists) have little clue about critical thinking – a process to help us weed out the BS from the kosher. Most of us use our gut feelings, and such feelings have served archaeologists well. They carry about their experience and knowledge, and apply it both consciously and subconsciously in their work – they don’t plug variables into equations or run proper experiments – they interpret what their techniques (some of them hard science) reveal, and peer review takes care of the rest. The problem with dowsing is that it purports to provide the same hard facts of the scientific side of the field, when in fact it is based wholly in the other and produces even less useful results. It is, in fact, a massive red herring.

In the next part of this article, I’ll analyse a recent attempt to rehabilitate archaeological dowsing as part of a questionable new approach dubbed ‘Spirit of Place’.

Update 18.8.09 – thanks to Keith Harmon in the comments below for (if inadvertently) leading me to another example of a museum pushing archaeological dowsing to a credulous audience – Gunnersbury Park, operated by the respected Museum of London.

Update 3.9.09 – some vintage dowsing going on at no less a site than the Tower of London by a Major C.A. Pogson –  dowsing luminary and official water diviner for the Bombay government. The treasure they had supposedly found – Barkstead’s Treasure – remains undiscovered to this day – the ‘treasure’ that they were plonking into finds trays (without the assistance of the dowsing chappie) appears to consist of bits of pot and animal bone (rather more usual archaeological finds).