I recently ran into this post on the Ideomotor Response, a real and captivating effect. You experience unconscious, unintentional physical movements that seem to contain knowledge beyond your own. It’s sort of neuromotor crosstalk that feels magical and has given us Ouija boards, automatic writing, and dowsing.
If you’ve never tried dowsing, give it a shot. It’s one of those remarkably compelling experiences that only science can sort out.
As I had a chance to see for myself.
Out here in rural New Mexico a lot of well drillers use, or at least offer, dowsing. I live on thick layers of ancient limestone and dolomite, crisscrossed with volcanic intrusions and alluvial deposits. Water is usually deep and not found in the lovely, predictable aquifer layers that favor much of North America. We see a lot of expensive dry holes.
Superstitions thrive when you seek an outcome that is very important but heavily influenced by chance. Whether winning a ball game or drilling a well, it’s hard to avoid developing a belief in lucky socks or dowsing. The ideomotor sensations are compelling – dowsers are honest people.
One of my neighbors was convinced he could detect water with dowsing rods. He was as curious as I was to find out if dowsing could be proven. We worked out a test protocol, and agreed that 5 or more “Hits” would be good evidence.
I added my procedure under the More Tag below – feel free to use it if you’d like.
Here are our results:
My neighbor got 2 hits, well within chance and below his expectation. He’s a bit mystified (indeed, one experiment needs to be replicated) but it was fun to be able to run an experiment ourselves.
Test of Dowsing for a Half-Liter Bottle of Water
Set-up crew (one person to set up and one to record results)
Observer to record dowsing results
Retreat Areas: Both the Set-up Crew and Dowser & Observer must have nearby areas where they are isolated from each other and the equipment.
Half-liter bottle of water
6 empty yellow plastic cat litter buckets, numbered 1 thru 6 (nest pairs of buckets together if necessary to ensure they are opaque)
Piece of plywood to provide a flat surface
Set-up sheet – paper with rows numbered 1 thru 10
Results sheet – paper with rows numbered 1 thru 10
Set Up will be outdoors:
Dowse a candidate area to find a place free of interference – we used about 80 feet by 10 feet.
Dowser may select the area in advance but will confirm it is acceptable before starting the test.
Set out the buckets, upside down, with 10 feet between.
With all personnel present, place the bottle under one bucket.
Perform a non-blinded set-up trial:
Dowse to be sure the bottle registers and empty buckets do not. Move the bottle to each bucket and repeat to be sure everything is working.
Lay the plywood down in the Setup Crew’s retreat area and set out the die.
- Dowser & Observer retreat to their area.
- First set-up person rolls die and moves bottle to under the corresponding bucket. Avoid leaving clues – walk along all the buckets and touch each one. Second person records the location of the bottle and observes to be sure the number rolled on the die is the number of the bucket where thebottle was placed. Retreat out of sight. Call dowser to begin.
- Dowser selects a bucket without touching any bucket.
- Observer records number of the Dowser’s selected bucket.
- Dowser and Observer retreat, call to Set-up Crew for next trial.
- Repeat until 10 trials are recorded.
Repeat the non-blinded set-up trial:
Dowse for the bottle under a bucket known to the dowser to confirm bottle registers and empty buckets do not register – to make sure everything is still working.
Place set-up and results sheets side by side. Place a check for each “Hit” on the results sheet. A “Hit” is defined as an exact match (selecting a bucket adjacent to the correct bucket is a “Miss.”)
The test will be analyzed as a binomial experiment, with 10 independent trials, each resulting in a Hit or Miss. The probability of a Hit by chance is 1 in 6 or 17%. Microsoft Excel function BINOMDIS provides the probability of obtaining various numbers of Hits by chance(presented below.)
We agreed in advance that five or more hits would be an impressive demonstration of dowsing.
If you guess you have:
- 16% chance of getting zero hits
- 32% chance of getting exactly one hit
- 29% chance of getting exactly two hits
- 15% chance of getting exactly three hits
- 5% chance of getting exactly four hits
- 1% chance of getting exactly five hits
- And less than 1% chance of getting more than five hits