Archaeological Dowsing (Part One) – Divining Bad Archaeology

Indy 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 BadScience.net 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).