May 09 2013

Nocebo Mass Delusion

Expectation bias cuts both ways, for positive and negative expectations. Expectation bias, the tendency to perceive and accept data that reinforces your expectation, is one of the many contributors to placebo effects (the illusion of a positive benefit that derive from something other than an active treatment). It is also, however, part of nocebo effects  (the illusion of negative side effects from something other than active treatment).

Expectation bias can be powerful enough in some people to lead not only to the perception of a benefit or side effect but to a frank delusion. When this happens on a large scale, that can lead to a mass delusion. There are many episode that demonstrate this effect, but now there is also a controlled experiment that also confirms it.

A recent study looked at sham exposure to wifi signals in 147 subjects. They were first exposed to either a documentary about the dangers of wifi, or to a documentary about internet security. A total of 54% of the subjects experienced

“…agitation and anxiety, loss of concentration or tingling in their fingers, arms, legs, and feet. Two participants left the study prematurely because their symptoms were so severe that they no longer wanted to be exposed to the assumed radiation.”

Further, the group exposed to the wifi documentary experience significantly more symptoms.  This is a small study but it matches prior research showing that those who believe they have electromagnetic sensitivity will experience symptoms when exposed to sham EMF. The difference with the current study is that it used healthy volunteers and controlled for media exposure.

Systematic reviews of the research on EM hypersensitivity show that those who self-identify as having EM hypersensitivity (which has now been renamed in the technical literature as “Idiopathic environmental intolerance attributed to electromagnetic fields”) cannot tell the difference between real and sham EMF. This review concluded:

” No robust evidence could be found to support this theory. However, the studies included in the review did support the role of the nocebo effect in triggering acute symptoms in IEI-EMF sufferers. Despite the conviction of IEI-EMF sufferers that their symptoms are triggered by exposure to electromagnetic fields, repeated experiments have been unable to replicate this phenomenon under controlled conditions.”

The new study suggest that this nocebo effect can happen on a large scale due to media reports, and cautions the media about sensationalizing such reports.

Perhaps the most famous recent example of this phenomenon is the Pokemon Contagion episode. In December 1997 it was reported widely by the media in Japan that one  particular episode of Pokemon that involved flashing lights provoked seizures in a few susceptible children (they had photosensitive epilepsy). This led to over 12,000 reports of symptoms among children watching the episode. Analysis of cases found that only a very few cases were legitimate seizures, the rest appeared to be anxiety provoked by the media reporting.

Robert Bartholomew is a sociologist who specializes in delusions. He wrote an excellent article for the Skeptical Inquirer in which he documents many of the mass delusions over the last millennium. My favorite is the Seattle Windshield Pitting Episode of 1954. The observation of small pits in the windshield of a car led many in the public to examine their own windshields, finding similar pitting. This led to wild speculation about atomic fallout and other causes.

What is clear from both research and historical cases is that media reporting can provoke a self-fulfilling phenomenon by creating the very symptoms that are being reported. Ideally, media outlets will show restraint and professionalism when reporting on possible medical risks. (I’ll stop there as your hysterical laughter will probably keep you from being able to read further.)

28 responses so far

28 Responses to “Nocebo Mass Delusion”

  1. oldmanjenkinson 09 May 2013 at 9:01 am

    What is so interesting about this psycho-somatic “phenomenon” is that the earth is bombarded by electromagnetic radiation 24hrs a day (23hrs 56 mins) 365 days a year. If this diagnosis were a true condition these individuals would be “suffering” symptoms non stop. I think it is another “pathalogizing” something that is a nothing. IMO it is a halo effect. It is amazing what our minds can create and for these individuals their perceptions makes it “reality.” Our mind truly is a deception engine.

  2. evhantheinfidelon 09 May 2013 at 9:30 am

    This reminds me of when I was a younger kid and I took four vitamins. I know that wasn’t too good for me (the cap on the label was two, I believe), but I was so convinced that I was dying that I went to hide in the closet and started puking from the anxiety, which fed further into my delusion.

  3. ccbowerson 09 May 2013 at 10:03 am

    Controlled research in this area is tricky, because of ethical considerations of possibly introducing negative symptoms with no benefit to the participants. Fortunately we have many real life examples of mass delusions and mass psychogenic illnesses to learn from. Thanks for the link to that article BTW. In addition to the famous examples, such effects happen more commonly on smaller scales with strange smells and apparently ill people in offices and in other close quarters like trains and planes.

  4. Kawarthajonon 09 May 2013 at 12:07 pm

    This is great. I have people at my work who say they are sensitive to wifi from the business below and I’ve always thought that this was nonsense, not to mention that the free signal from below is too weak for me to get a consistent wifi connection.

    I would be really interested in Steve doing an article on similar sensitivity to wind turbines. People in my area are up in arms about the health effects of wind turbines that are located at least more than 500m away from their houses – they even have signs saying “Think of the Children, Say No to Wind Farms”. They list a number of non-specific symptoms and I believe it is all the nocebo effects, along with other fantasy dangers (i.e. blades coming off the towers and flying more than 500m into people’s heads). Sounds like a similar phenomenon to me.

  5. steve12on 09 May 2013 at 12:38 pm

    We’re having a particularly troubling episode of this in the Boston area, where windmills are said to be causing health problems similar to those claimed about EMF.

    Our public radio station was reporting on the phenomena, and related drive to remove the windmills, and did a horrible job representing the science, getting a quote from a public relations guy a a local environmental education group who spouted a bunch of false equivalency nonsense. This was the type of reporting that leads to this belief (and therefore symptoms for some) becoming more widespread.

    I emailed the reported – but he of course never got back to me. Now that journalism is a giant he said/ she said bifurcation error a go go there’s no need to consider that actual truth, but that’s another story…

  6. steve12on 09 May 2013 at 12:40 pm

    ” People in my area are up in arms about the health effects of wind turbines that are located at least more than 500m away from their houses – ”

    Are you in Boston?

  7. Ori Vandewalleon 09 May 2013 at 1:11 pm

    Some really rough approximating tells me that if you’ve got a wind turbine blade 210 feet off the ground with a tip speed of 180 mph and it is magically released from the nacelle at its highest point and there’s no air resistance (hmm…) then it will travel about 150 meters before hitting the ground. That’s an upper limit, and it’s using terrible assumptions.

    (One assumption I didn’t mention is that its center of mass is in the geometric center of the object, which I’m guessing is not true. If the center of mass is closer to the ends of the blade, it will travel farther before hitting the ground, but not more than twice as far as I said above. Another assumption is that it falls the full 210 feet before hitting the ground, which is ridiculously unlikely.)

    Anywho, yeah, there’s no chance of a wind turbine blade going half a klick.

  8. ConspicuousCarlon 09 May 2013 at 1:21 pm

    Further, the group exposed to the wifi documentary experience significantly more symptoms.

    What were the actual numbers of symptoms for each group?

  9. Steven Novellaon 09 May 2013 at 1:29 pm

    I have to say, the write up of the data in the study is terrible. There does seem to be a consistent effect, but only when you combine exposure to the wifi film and attribution of symptoms to wifi, which at least makes sense. But they express everything in standard deviations and risk, etc. without giving a clear breakdown of the raw numbers. (I have access to the full article, which is behind a paywall.)

    The primary weakness of the study, it seems to me, is that they look at many variables and comparisons. Seems ripe for the “researcher degrees of freedom” problem.

  10. steve12on 09 May 2013 at 1:39 pm

    And in case anyone was wondering, the wind turbine illness similarly lacks any evidence of a link (I found no peer reviewes work showing one) and looks like nocebo:

  11. nickmPTon 09 May 2013 at 1:51 pm

    The worried well strike again. Do you think better education overall would help this phenomenon, or is there just some personality quirks that will always be present? (I know this asks for a lot of certainty of the uncertain, more just seeking an opinion)

  12. steve12on 09 May 2013 at 2:13 pm

    “The worried well strike again. Do you think better education overall would help this phenomenon, or is there just some personality quirks that will always be present? ”

    I think it’s fair to say that the particular varietal of BS covaries with socioeconomic status, region, identity politics etc. along with personality characteristics. We all have our anecdotes, but who’s more likely to to deny evolution vs. not vaccinate their kid: a pipe fitter from South Carolina or a Ph.D. in English from New York? My hunch is that there’s some polling data that bears this out.

  13. SimonWon 09 May 2013 at 5:38 pm

    Since mobile phones operate with similar frequencies, often at higher power and closer proximity, did they control for those? I assume anyone with genuine(?) sensitivity wouldn’t have a mobile phone, but might be exposed to signal from the tester’s or other participants.

    There are some signalling difference, but I’d expect mobile phones to nearly always be worse.

    I’m reminded of people trying to improve their wifi, because the signal broke up whenever they used their microwave oven. How much do we have to teach people about physics before they realize they need to sort the microwave oven’s shielding.

  14. ConspicuousCarlon 09 May 2013 at 7:42 pm

    Maybe the difference between test and control groups is actually weakened by the fact that everyone has already heard about teh evilz oF wIfI. Watching the scaremonger video beforehand would be expected to add dramatic effect even if the subject already knows about the claims, but both groups got the drama of “We are turning on the WiFi (DUN-dun-DUNNNN…)… does your head hurt?” Neither group was really free of scare cues.

  15. Kawarthajonon 09 May 2013 at 9:04 pm


    I’m in Ontario. There is a new push to make Ontario a clean energy producer so there are wind/solar farms going up all over the place, although there has been huge opposition to wind farms because of the supposed health effects.

  16. banion23on 09 May 2013 at 11:45 pm

    The concern about flying blades is ridiculous, though ice can and does accumulate on the blades near the hub. The ice forms in sheets, and some of the ice blocks can be half the size of a car. These ice sheets can be “flung” by the blade. In a “perfect storm” of sorts, the slinging action is similar to putting a rock in a wrapping paper tube and slinging it. The tips of the blades on some of the larger units are traveling hundreds of miles per hour. This isn’t really anything to be worried about.

    In regards to EMI, it’s ridiculous to assume that windmills are creating that much electromagnetic interference. I could understand resonance at lower frequencies traveling through the ground, but again this is highly unlikely. The bottom line is these people who are fighting against windmills are what we like to call “NIMBYs.”. You’ll find there are 2 types of people who don’t advocate for windmills–the “global warming is fake” crowd (i.e. people who deceive themselves into believing everything is fine until it is too late) and people who don’t want them in their backyards. Both are ignorant. So they’ll make up anything to oppose windmills and windmill legislation. Ironically, some of these people consider themselves “green”, and usually have a 200A service hooked up to their 3,500 sq. ft home that they heat 100% of in the cold months, while walking around in “save the world one bottle at a time” and purchase a new hybrid car that takes many barrels of oil to manufacture.

    What a strange, delusional world we live in.

    But, in regards to the post, it’s very interesting. I believe, as well as it has been proven, that mind over matter is true, to varying levels depending on the situation. People have cured themselves of cancers mysteriously without treatment, weaker people have lifted cars to get their children out from under them, people have had insane luck that is virtually improbable, and many other situations through mind over matter. I definitely believe that people that think they’re sick all the time end up getting sick, even though they weren’t in the first place. And I’ve experienced having an easy time picking up large weight because I wasn’t aware of the weight, and had a hard time picking up some things because I thought they were much heavier than they were.

  17. banion23on 09 May 2013 at 11:50 pm

    oh, also, look around the internet for videos of windmill disasters.

    But the bottom line is this: Windmills go up easy, and will come down easy. Until we find more efficient means of electrical generation with lower TCO, this is what we have. The good news is when we do find more efficient electrical generation that costs less to maintain/repair it will be easy to take the windmills down and reuse the materials. Literally remove the wiring remove the bolts, and tip the thing over. Or take it down piece by piece if the windmills are sold to another country, hopefully one that has limited electrical generation and/or distribution.

    Sorry to talk so much about windmills, I’m just familiar with them, that’s all.

  18. Bruce Woodwardon 10 May 2013 at 4:09 am

    I am surprised no one has linked autism to Wifi signals.

    While we are at it, how about that inverse relationship between pirates and global warming!

    Save our planet!!! Bring back the pirates!!! aaarrrrr!!!

    On a serious note, it is annoying that the data for a study that debunks these kinds of things is behind a paywall when idiots give out bad information for free.

  19. BillyJoe7on 10 May 2013 at 8:59 am

    banion: “Sorry to talk so much about windmills, I’m just familiar with them, that’s all”

    Yeah but…what do you know about wind turbines?

  20. ccbowerson 10 May 2013 at 1:04 pm

    “Yeah but…what do you know about wind turbines?”

    Hmm. Maybe these wind turbines generate electricity that power machines that turn grain into flour.

  21. Kawarthajonon 10 May 2013 at 2:14 pm


    Thanks for your post. It’s not EMI people are worried about in my area, it is low-frequency sound waves caused by the turbines that they think can cause things like anxiety, headaches and other non-specific symptoms.

  22. BillyJoe7on 10 May 2013 at 5:37 pm

    “Hmm. Maybe these wind turbines generate electricity that power machines that turn grain into flour”

    Good one.
    (Well, not bad)

    But actually I made that comment more in line with Kawarthajon’s last comment.
    Banion doesn’t seem to understand what the objection is that people have to wind turbines.
    Having said that, I’ve just realised that I don’t know what he means by EMI.
    As far as I know EMI is a music company…the irony!

  23. Jared Olsenon 10 May 2013 at 9:41 pm

    Reminds me of the ‘Werther Effect’
    I seem to remember a ‘gentleman’s’ agreement amongst the media not to sensationalise high profile
    suicides because of this effect. But, as you said Steve, restraint in the media is laughable.

  24. tmac57on 11 May 2013 at 11:21 am

    Bruce Woodward-

    I am surprised no one has linked autism to Wifi signals.

    Be surprised no more…here you go:

  25. Bruce Woodwardon 13 May 2013 at 4:08 am

    The comments on that site are quite entertaining. Thanks for that.

  26. Bill Openthalton 13 May 2013 at 9:23 am

    The Coca-Cola hysteria in Belgium in 1999 was another example of this phenomenon. In Bornem, 42 school children became ill and had to be hospitalised apparently after drinking Coca-Cola, and this was widely reported in the press. Over the next days, kids in other towns became ill as well, forcing Coca-Cola into a huge product recall. The investigation showed that a batch of Coke was manufactured with carbon-dioxide tainted with sulfur compounds. So far, so good.

    The subsequent scientific analysis (in which I had a tangential involvement) showed that the level of contamination was so low (between 5 and 17 ppb) the sulfur compounds could not be the reason for the symptoms. It was also discovered that in four of the five or six schools, the children who had been hospitalised hadn’t been drinking Coke that day. The conclusion of the report was that Coca-Cola wasn’t responsible for the symptoms at all and labelled the outbreak a case of mass-hysteria.

    What it did lead to is firm opposition to the presence of soda vending machines in schools, and even some government action to force the removal of the machines (which were sponsored by the soft drink industry — schools got money for education projects if they allowed vending machines on their premises).

    Humans are a weird species 🙂

  27. antiqueston 13 May 2013 at 1:57 pm

    I would be curious to hear how treatment for someone who suffers from EM sensitivity would work. Even if there is no physiological effect, these people aren’t faking it, they’re really suffering so they really do need help with their symptoms. Clearly, just telling them it’s all in their head won’t work.

    How effective is placebo in treating nocebo? Would it be ethical in this situation to prescribe a placebo or do they really just need therapy?

  28. Bill Openthalton 14 May 2013 at 5:56 pm


    Obviously, if there are no effects of the EMR on the tissues, there is an effect of the (real or presumed) presence of the EMR on the brain of the sufferer, which is a physiological effect.

    In my opinion, anything that improves the wellbeing of people who feel pain is ethical, as long as it does not negatively affect other people. What is not ethical is using methods that do not work, like in the case of an acquaintance of mine who has been receiving more than 10 years of acupuncture to treat his asthma, but still carries an inhaler, and informs me his acupuncturist says his treatment is a long-haul affair, another decade or so — which it will be, as it doesn’t do anything. Clearly he is scared of steroids and other asthma medication, and comforted by the acupuncture, but that doesn’t make it ethical.

    In matters of the mind though, placebos can cure if they change the patient’s perception. They might be a placebo with regard to the (non-existing EMS), but they are a cure for what ails their mind, much like psychotherapy would be.

Trackback URI | Comments RSS

Leave a Reply

You must be logged in to post a comment.