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Ideomotor Response

Donate The Ideomotor Response underlies a number of occult phenomena and alt-med practices.  

by Kevin Hoover

Filed under Alternative Medicine, Consumer Ripoffs, Fads, General Science, Health, Paranormal

Skeptoid Podcast #451
January 27, 2015
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Ideomotor Response

What if you had the power to detect unseen things buried deep in the ground? Or channel messages from spirits? Even more useful, what if you could help handicapped persons who can't express themselves to communicate? The good news is, you already have these powers. Bad news, they aren't powers at all. These and other uncanny phenomena reflect a quirk of physiology known as the Ideomotor Response.

The Ideomotor (or Ideomotor) Response (or Reflex, or Effect) - is a term for the unconscious, unintentional physical movements which sometimes occur while you experience thoughts or memories, or feel emotion. IMR visits its neuromotor crosstalk on our throbbing gristle in countless ways.

You mash your right foot down onto a nonexistent brake while watching a movie car chase, or mindlessly drum on your desk to a familiar tune, maybe you lunge for a video game controller in response to a real-world situation, or draw an elaborate doodle while pondering something else entirely. Hello, IMR. And that's just the start.

While the mind is far from fully understood, Ideomotor movement links thoughts and feelings with unintended action in well-defined ways.

IMR isn't widely appreciated or always recognized. You may have no awareness of executing the movements. All this opens the door to suggestions that external, metaphysical forces are in play.

While a function of the nervous system isn't the same thing as a magical, mystical power, that's something the superstition salespeople Don't Want You To Know. They've got plenty of fanciful uses for IMR that often include a consciousness-expanding price tag.

Carpenter nails it

In case you missed Dr. William Benjamin Carpenter's lecture at the March 12, 1852 meeting of the Royal Institution of Great Britain, that's where "Ideo-Motor" gained its retro, vaguely steampunk name and why it's sometimes called the Carpenter Effect.

Fusing the term "ideo," for ideas, and "motor," for muscular movement, Carpenter's compound term married observations of IMR with what was surmised about the mind and nervous system in his day. He created a sort of signal flowchart tracing the way thoughts might become actions.

...And as we have seen that the emotions may act directly upon the muscular system through the motor nerves, there is no a priori difficulty in believing that Ideas may become the sources of muscular movement, independently either of volitions or emotions.

Carpenter was an omnivorous intellect and, later in life, quite the skeptic. Right away, he linked ideomotor movement to hypnotism, sleepwalking and what we now know to be Placebo Effects. Other scientists expanded and further defined the phenomenon based on his pioneering work.

As usual, mere knowledge doesn't automatically disengage the superstitious from their exploiters, or make much of a dent in their historical co-dependency. Let's dwell on the most persistent - and profitable - misimplementations of Ideomotor Response.


Even in introducing the concept, Carpenter linked ideomotor activity with divination.

Divining rods are used to detect all kinds of underground resources. If you're looking for water, oil, buried treasure - whatever you need and are willing to pay for - practitioners have been ready to cash your checks since the fifth century. It's a rich tradition.

Dowsing, or water witching, involves use of twigs, rods, pendula or other contraptions. An operator holds the device and sweeps it over the area being surveyed. Antennae swivel and point to where digging should take place.

The process by which this remote sensing occurs is variously described as vibration, radiation, magnetism and that old favorite, energy or Qi. These "divine" forces are channeled in some occult fashion from the coveted material via the shiny utensil to the practitioner. In other words, it's magic!

In reality, it's the combined power of IMR and cognitive bias - the usual correlation/causation mashup, topped off with arguments from tradition and popularity.

Dowsers and their customers are, literally, invested in the notion that it works. The dowser is being paid to find something via a magical process and has that sweet dowsing rig to pay for, so involuntary muscle movements are inevitably going to animate the instrument in a manner consistent with commercial expectations.

If it does this five, 10, 20 times with no result, but then strikes gold (in one form or another) somewhere, fallacious Post Hoc Ergo Propter Hoc reasoning links statistically meaningless cause with happy ending and voila! - through the non-magic of motivated reasoning and confirmation bias, another testimonial is born and a timeless tradition is upheld.

So is a major profit center. These days, water witchers adopt a sciencey/techy overlay to help command juicy fees for products and services.

While a simple dowsing rod might set you back just 15 bucks, professional setups incorporating all the "latest technology," and cossetted in fine leather cases, go well into the four figures and beyond.

But hey, they wouldn't sell this stuff if it didn't work, right?

Wrong. Like Feng Shui advisors, astrologers and other woo-slingers, dowsers don't agree among themselves on proper procedures and standards. Some witchers, for example, wear rubber shoes, while others would never.

And there's no data to back up anything about dowsing. Study after study has shown it to be no better than guesswork, the results indistinguishable from statistical noise. But for every damning dowsing data point, there's at least one folksy testimonial or YouTube video to counter it.

Dowsing is one of those old school bits of superstition that skeptical pioneers like Carpenter, and later, the Amazing James Randi, have roundly debunked.

Look, if people want to spend their money on useless products and services, make friends and uphold tradition - hey, what's the harm? Well, it's all fun and games, until it isn't.

Bomb Detection

During the Iraq War, asymmetric warfare in the form of cheap, easily concealed car bombs and suicide bombers killed and injured thousands. While others mourned, scammers sensed an opportunity. Soon, a host of IMR-based explosives-detection devices came to market.

They weren't cheap. These "remote substance detectors" - essentially bomb dowsers - fetched thousands, tens of thousands and even hundreds of thousands of dollars.

Desperate for solutions and flush with cash, various militaries were quick to snatch up these devices at any price.

One of the most notorious was the "Alpha 6" dynamite detector, assembled by British subjects Samuel and Joan Tree in their garden, using cheap mail-order parts from China.

A plastic box with no electronic components, just a freely rotating piece of metal billed as an antenna, the Alpha 6 was actually a rebranded golf ball detector previously marketed as the "Gopher."

Where the Gopher sold for $12, the near-identical Alpha 6 fetched more than $3,000 and up to $25,000. The government of Egypt placed an order valued at more than $1.5 million for a fleet of Alpha 6 units.

Mr. and Mrs. Tree raked in an estimated $3 million before a BBC investigation revealed the scam. In 2012, the couple was convicted of fraud, and sentenced to jail and community service. Cruelly, the bomb detectors were also billed as able to locate missing children.

The Trees weren't alone. Other ineffectual, ideomotor-based bomb dowsers sold for as much as a half-million dollars. They were used at military checkpoints in Iraq, allowing fully loaded truck bombs right on through to strike that country's justice and foreign affairs ministries.

An even more suave-looking, brushed-metal device called the Sniffex was marketed to the U.S. military in the mid-2000s. After purchasing eight Sniffex explosives detectors for $50,000, the Navy subjected them to double-blind testing using TNT and C4 explosives.

Results were no better than random chance. A truck loaded with 1,000 pounds of explosives and driven within 20 feet of the Sniffex failed to elicit any indication.

Investigators didn't bother with diplomacy or bureaucratese in their assessment. "The Sniffex handheld explosives detector does not work," the Navy concluded. "There was absolutely no indication the device met any single vendor claim."

In response, Sniffex vendor Paul B. Johnson offered special pleading. He claimed that the Yuma Proving Ground where the device was tested was polluted with explosive residue which skewed the results.

But the Navy got it right, squarely placing the Sniffex's random antenna deflections on the operator's Ideomotor Response.

Even without a bombing range to play around with, the Amazing Randi swiftly sussed the Sniffex as nothing more than a fancy divining rod. He invited Johnson to prove its efficacy in the James Randi Educational Foundation's One Million Dollar Paranormal Challenge. Johnson declined.

Facilitated Communication

If IMR was able to bamboozle some of the military some of the time, just imagine its potential in the world of alternative medicine.

Hypnotism depends heavily on IMR, as does chiropractic. But these days there's something even more sciencey: Facilitated Communication, or FC.

FC popped up in the 1970s. It is used to assist persons who have communications impairments such as autism, with expressing themselves. The theory is that they some have "undisclosed literacy" which FC can reveal and amplify.

An FC facilitator holds the arm of an impaired subject, supports them and helps guide the person's finger toward a special alphanumeric keyboard. The subject may then answer questions, converse or just tap out statements. In other words, communicate.

Initial responses were dramatic and persuasive, gaining accolades in the special education community and spurring adoption of the practice.

You know what comes next. When FC was tested using scientific method, its usefulness evaporated. The responses were found to be those of the facilitator, not the subject - something the well-meaning facilitators were often unaware of.

FC survives even though it is basically a parlor trick gussied up as "augmentative communication." It's a latter-day iteration of automatic writing, an IMR-based practice which has been deluding the credulous and profiting practitioners for centuries.

Virtually every serious organization involved with communications therapy, from the American Psychological Association to the American Academy of Pediatrics and others have repudiated FC as useless.

Ouija Boards

While the average person might go through life never needing a dowser's services, a bomb detector or Facilitated Communication, almost everyone has tried out a Ouija Board. They're a lot of fun - in the right hands.

First introduced as a toy in 1890, the Ouija or Talking Board is a flat board typically embellished with the alphabet, numbers 1 through 0 and the words "YES," "NO" and "GOOD BYE."

Like FC, it relies on users to manually spell out words. A person or two people sitting side by side will hold the board in their lap. The operator places a hand on a pointer called a planchette, which wanders from letter to letter, seemingly on its own and guided by supernatural forces, to spell out words.

Spiritualists seized on the Ouija Board and popularized it as a divining tool. But the boards have also been denounced as witchcraft and demonic influence.

The operative function is plain old IMR. It's yet another form of automatic writing dressed up this time as a "mystical oracle." Today's Ouija Boards sell for $20 to many times that, and come in compact and glow in the dark models.

Astrophysicist Neil deGrasse Tyson said Ouija Boards are his favorite form of woo. He likes the way the channeled spirits tend to make the same spelling errors as the person prodding the planchette.

And so on

Seeing through dirt and walls, facilitating the impaired, talking to the dead - oh, Ideomotor Response, is there anything you can't do?

Probably, although the limits of IMR's commercial exploitation have not yet been discovered. To this day, bogus IMR products and services continue to spring up.

Aura meters, Applied Kinesiology, Traditional Chinese Medicine, radiesthesia and countless other dodgy gimmicks all rely on IMR. All have fierce defenders who will regale skeptics with oft-told stories of personal experiences and uncontrolled, unscientific experimentation.

We'll go out on a limb here and look for answers from science - not toy manufacturers, alt-med hucksters or war profiteers.

Next time you smack your lips thinking of Mom's apple pie, or grimace at memories of your Auntie Grizelda's goulash, thank scientist William Benjamin Carpenter for first unveiling the secrets of the Ideomotor Response.

By Kevin Hoover

Please contact us with any corrections or feedback.


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Cite this article:
Hoover, K. "Ideomotor Response." Skeptoid Podcast. Skeptoid Media, 27 Jan 2015. Web. 30 May 2023. <>


References & Further Reading

Carpenter, Willian Benjamin. "On the influence of suggestion in modifying and directing muscular movement, independently of volition." Proceedings of the Royal Institution of Great Britain. 12 Mar. 1852, Unknown: 147-153.

Carroll, R. "Ideomotor Effect." The Skeptic's Dictionary. Robert T. Carroll, 12 Sep. 2014. Web. 5 Aug. 2015. <>

Easton, R., Shor, R. "An Experimental Analysis of the Chevreul Pendulum Illusion." The Journal of General Psychology. 1 Jul. 1976, Volume 95, Number 1: 111-125.

Hyman, Ray. "How People Are Fooled by Ideomotor Action." Quackwatch. Stephen Barrett, M.D., 26 Aug. 2003. Web. 5 Jan. 2015. <>

Randi, James. An Encyclopedia of Claims, Frauds, and Hoaxes of the Occult and Supernatural. New York: St. Martin's Press, 1995. 128, 169, 177, 228.

Tyson, Neil deGrasse. "Star Talk Radio." Star Talk Radio. Curved Light Productions, 21 Dec. 2014. Web. 27 Dec. 2014. <>


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