The plausibility effect

July 12th, 2008 by Ben Goldacre in bad science, electrosensitivity, Lucy Johnston, Lucy Johnston Express, psychology of woo, roger coghill, secret data | 31 Comments »

Ben Goldacre
The Guardian,
Saturday July 12, 2008

You will remember, two weeks ago now, we saw the Sunday Express claiming on its front page that an impressive government adviser called Dr Roger Coghill had performed a research study demonstrating that the Bridgend suicide cases all lived closer to a mobile phone mast than average. When I contacted Coghill it turned out he wasn’t really a government adviser, he had previously claimed that Aids was caused by power cables, he said the Express had made a mistake in calling him a doctor, he had lost the data, and he couldn’t even explain what he meant by “average”.

You will be very pleased to hear that Dr Coghill has now found the data.imageThis is a matter of great public health significance, as suicide is the second most common cause of death in men aged 15 to 44, and mobile phone use is extremely prevalent. Sadly Dr Coghill still does not wish to tell me what figures he collected, what analysis he did on them, what “average” he compared them with, what the results were, and what interpretation he makes from these results. This baffles me. He claims online that he has offered to let me inspect his data but that I declined. This baffles me too, because he also explains – in a complaint to the Press Complaints Commission about me harassing him – that he will not give me his data, as he considers it “sensitive”.

I’ve no interest in a squabble. Please, Dr Coghill, these are important issues you have raised, I would like to take you seriously: you need not hand over the raw data, but it would be a kindness to those affected by your front page revelations if you could take the time to answer my simple, clear questions.

Without data, we have only a bloke. Week in, week out, we see apparently scientific claims being made in the newspapers with great confidence, as if they were based on evidence, when in reality they are based on nothing more than authority, and often from one man. This is because science is communicated to the public by journalists, who sometimes have no understanding of what it means for there to be evidence for an assertion. They are impressed by enthusiasm, long words, by a PhD, a white coat, or a medical qualification.

What if this is taken to an extreme? In 1973 a group of academics noticed that student ratings of teachers often seemed to depend more on personality than educational content. They wanted to find out how far this effect could be stretched: what if you had an impressive, charismatic and witty lecturer, who knew nothing at all about the subject on which they were lecturing? Could plausibility alone make an audience feel satisfied that they had learned something, even if the information delivered was deliberately inconsistent, irrelevant, and even meaningless?

They hired a large, affable gentleman who “looked distinguished and sounded authoritative”. They called him “Dr Myron L Fox” and he was given a long, impressive, and fictitious CV. Dr Fox was an authority on the application of mathematics to human behaviour.

They slipped Dr Fox on to the programme at an academic conference on medical education. His audience was made up of doctors, healthcare workers, and academics. The title of his lecture was Mathematical Game Theory as Applied to Physician Education. Dr Fox filled his lecture and his question and answer session with double talk, jargon, dubious neologisms, non sequiturs, and mutually contradictory statements. This was interspersed with elaborate diversions into parenthetical humour and “meaningless references to unrelated topics”. It’s the kind of education you pay good money for in the UK.

The lecture went down well. At the end, a questionnaire was distributed and every person in the audience gave significantly more favourable than unfavourable feedback. The comments were gushing, and yet thoughtful: “excellent presentation, enjoyed listening”, “good flow, seems enthusiastic”, and “too intellectual a presentation, my orientation is more pragmatic”.

The researchers repeated the performance. Time and again they got the same result: the third group consisted of 33 people on a graduate-level university educational philosophy course. Twenty-one had postgraduate qualifications. They loved it: “extremely articulate”, “good analysis of subject that has been personally studied before”, “articulate”, and “knowledgable”, they said.

Nobody can check everything, we’re all interdependent for information, and sometimes you might find yourself in a soulful, detached state, wondering whether everything you think you know is grounded in nothing more than a string of half-remembered assertions from people like Dr Fox.


Donald H. Naftulin, M.D., John E. Ware, Jr., and Frank A. Donnelly
Journal of Medical Education, vol. 48, July 1973, p. 630-635

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31 Responses

  1. JQH said,

    July 12, 2008 at 12:41 am

    He’s got the data but won’t show it? How does he square this with his assertion on the forum that he’s going to take us through the peer-reviewed evidence that supports his position.

    We’re all still waiting.

    And when is he going to correct the Sunday Excess’s assertion that he’s a “Dr” and sits on a government advisory committee? Neither are true.

  2. bob_calder said,

    July 12, 2008 at 2:36 am

    At this point the guy is probably praying for a way out that isn’t utterly humiliating.

  3. rthibode said,

    July 12, 2008 at 4:40 am

    Thanks for exposing this. The screaming headline in the Sunday Express is embarrassing.

    Careful, please, about conclusions from the Dr. Fox study. You say “student ratings of teachers often seemed to depend more on personality than educational content.” The fellow who played Dr. Fox gave only one lecture and spoke on an area outside the students’ expertise. It would be a mistake to conclude that students prefer personality to substance in their lecturers, or that student evaluations of teaching are inherently unreliable.

    I know Dr. Goldacre is making a different and valid inference from the Dr. Fox study — that people can be tricked by phony credibility.

    For more on critiques of the Dr. Fox study, search the listserv archives of the Professional and Organizational Development Network in Higher Education ( for further discussion.

  4. Norbury said,

    July 12, 2008 at 9:53 am

    This is shaping up to be a classic confrontation. Do the PCC publish results of complaints?

  5. phayes said,

    July 12, 2008 at 9:55 am

    Dr Cogloose is an unusual crackpot if he does feel humiliated.

  6. Mojo said,

    July 12, 2008 at 11:26 am

    “Do the PCC publish results of complaints?”

    There is a brief summary for adjudicated cases and an even briefer one for “resolved” cases.

    Here’s an example of a resolved case:

  7. michaelandreas said,

    July 12, 2008 at 12:56 pm

    Have you noticed Mr. Coghill’s “challenge” involving a bet on a newborn’s life?
    Hopefully he does not believe his own claims, otherwise his ethics and moral values might perhaps be considered as somewhat distorted. Anyway, an interesting application of psychological models of decision making (value of a newborn’s life * perceived risk) and sociology (social norms concerning the abuse of a newborn as a bet).

  8. Sili said,

    July 12, 2008 at 11:07 pm

    Hazing of various kinds seem to be a staple of greeting rus at uni.

    I think using ‘plants’ in the initial tutoring groups is more used here in Denmark, but I seem to recall a lecture that was taken over by invading students at some point, too.

    I never did pay much attention those first years …

  9. danohuiginn said,

    July 13, 2008 at 10:57 am

    Interesting. I’d never heard of Myron L Fox before. Compare to Sokal, who gets trotted out all the time. I’m sure that goes to show something…

  10. Billy the kid said,

    July 14, 2008 at 3:04 am

    I noticed a letter by Roger Coghill in the BMJ (BMJ 2005;331:635) about the cancer risk that power lines pose to children. At the bottom of this letter it is stated that Mr Coghill has no “competing interests”.

    On its website ( the BMJ writes: “A competing interest exists when professional judgment concerning a primary interest (such as patients’ welfare or the validity of research) may be influenced by a secondary interest (such as financial gain or personal rivalry). It may arise for the authors of a BMJ article when they have a financial interest that may influence, probably without their knowing, their interpretation of their results or those of others… We used to ask authors about any competing interests, but we have decided to restrict our request to financial interests.”

    Does anyone want to provide a generous interpretation for why Mr Coghill does not financially gain from data that might demonstrate a link between electromagnetic radiation and cancer, thus clarifying why he does not have a competing interest in this topic?

  11. Mizuchy said,

    July 14, 2008 at 6:14 pm

    Dear Ben,

    First of all, I enjoy your column/blog very much.
    Second of all, this comment is not related to this post. It’s generated by pure contingency.
    Third of all (and I finally got to the point of this “comment”), looking at your amazon wish list I noticed that you received three copies of “The Dictionary of Fashionable Nonsense: A Guide for Edgy People” by Ophelia Benson and Jeremy Stangroom, a book which is currently unavailable and I was just wondering whether you might be willing to ship one copy of this book to me so that I could read it, and then ship it back to you?
    (I’ve become accustomed to this shipping to and fro of books by being an almost maniac user of, a website that allows its members to share books around the world.) I am willing to send you a cheque covering the shipping costs, if needed.

    Thank you!

  12. Ben Goldacre said,

    July 14, 2008 at 9:35 pm

    Absolutely nothing has been deleted from this thread, Mr Coghill. Nothing at all.

    I find it astonishing that you will stoop to pathetic attempts to smear, when all I have ever asked you for is details of your research study. Your dismal attempts at conspiracy theories do you no favours. i do not “protect” any “vested interests” as you falsely allege here and elsewhere, and if you say otherwise, then you are a liar, plainly and simply.

    You refuse to answer any of even the simplest questions about your research, and there is no possible justification for this. It is a great disservice to the people of Bridgend, and to yourself. Inevitably people will look into your background to see if there is a precedent for your activities, and while you attempt to smear, everything I have said about you is absolutely true, and requires no over-interpretation: you do sell ridiculuos magnetic therapy products for cash; you do sell asphalia melatonin pills to protect against the scares you elicit on the front page of the express; you did claim that aids was caused by power cables; the list is endless.

    but most important of all, you refuse to answer the simplest question about your research.

    What was the โ€œaverageโ€ distance from the mast that you were comparing against, in your study?

    You refuse to answer this simple question. You refuse to answer it, to great hilarity, over the course of this enormous and rather epic Commentisfree thread:

    which is possibly one of the most informative and revealing of such threads i have ever seen.

    Why will you not answer the simplest question about your research, Mr Coghill?


  13. mjs said,

    July 15, 2008 at 6:07 am

    hi Mizuchy,

    From what I can see, would be happy to sell the Dictionary of Fashionable Nonsense to you. For less than $10, hardcover.

    On the comment threads:

    I am flabbergasted. There is over an hour of reading material in the threads on the Coghill stuff. (links on the miniblog)

    I… um, I don’t know what to say. There’s nothing to add.

    Anyone interested in another Feynman Chaser? This one’s from a lecture at Cornell in 1964.

    …Wait, wait — there’s a Feynman Chaser channel now. ๐Ÿ˜€ Added… yesterday! Someone has PERFECT timing.

  14. pv said,

    July 15, 2008 at 1:50 pm

    Can I just say that Mr Coghill is correct in observing that there are fewer posts than previously. However, problems with the blog software aside, he still chooses not to answer a simple question (obviously because he can’t, one reason possibly because his “study” could be made up junk) and he is clutching at any excuse to create a diversion.
    One might expect this sort of infantile behaviour from someone who has something to hide, or someone accidentally discovered in a compromising situation.

  15. Andy said,

    July 15, 2008 at 5:13 pm

    Mr Coghill – Thank you for such a fine demonstration of irony.
    Within the same comment you first post an Ad Hominem attack on Mr Goldacre and this blog and then go on to complain that people are posting Ad Hominem attacks on your work.

  16. perspix said,

    July 16, 2008 at 12:40 pm

    My question is to Ben.

    Why do you hold Mr Coghill to such a high standard of account?

    It is self evident that Coghill is a charlatan and a mountebank and should be enough to hi-light his, and the Express’ chicanery.

    It’s not a particularly high standard, your question should be easy enough for him to answer, but it’s higher than is warranted for a twonk of his standing.

  17. Wonk411 said,

    July 16, 2008 at 5:51 pm


    I am not a regular at the Guardian site, so perhaps I have not figured out the code, but it appears to me that the comment thread to which you pointed on 14 July has gone walkabout. Is it cached anywhere?

  18. Andy said,

    July 16, 2008 at 10:11 pm

    The link Ben posted on the 14th still works fine for me. Going by the way the comments are loaded it looks like you need to have javascript turned on and possibly even have flash installed in order for the comments to show up. It could even be possible that an overly aggressive firewall would block them from being displayed.

    Unfortunately the people who approve website designs for things like newspapers are more interested in making them look nice than in compatibility.

  19. mjs said,

    July 17, 2008 at 6:55 am

    hi wonk411

    i had the same problem. never mind that error message– javascript IS turned on in my browser (safari). i’m going to guess that it’s a problem with the site coding.

    here’s a link to the comments all on one page:

    to get there, i clicked on :
    miniblog link –> read full article (scroll to bottom of article) –> go to comments –> comments all on one page

    happy reading ๐Ÿ™‚

  20. perspix said,

    July 17, 2008 at 9:39 am

    I would just like to apologise for hastily referring to Mr Coghill as a twonk and would like to respectfully substitute the term dilettenate.

  21. perspix said,

    July 17, 2008 at 9:41 am

    Dilettante – oops. Need coffee.

  22. GH05T said,

    July 17, 2008 at 2:03 pm

    rthibode, I wish it were true, as your July 12th comments suggest, that students with more knowlege of a teacher than a single lecture would be less gullible, but my personal experience leaves me unable to agree. Students in general can not be reliable judges of teachers. By the nature of the relationship the average student is expecting to be less knowlegable than the teacher and has been raised up (socially programmed) to sit quietly and listen. My attitude is based largely on an event way back in third grade when I asked my teacher about arachnids. I then had to explain that arachnids were spiders, ticks, and the like. My well-liked, young, and charismatic teacher announced in clear unmistakeable language “I think spiders are mammals because they have hair.” The other students not only took her word unquestioningly, but snickered at me for having once again been told what was what by the knowlegable authority in the room.

  23. Wonk411 said,

    July 17, 2008 at 7:19 pm


    Thanks for the help. A most interesting thread. I believe it can be aptly summarized with the following adaptation from a common /. meme:

    All your [basis] are belong to us!

  24. JQH said,

    July 18, 2008 at 8:55 am

    Seems I’m not the only person having problems with the Guardian site.

    I have to wait ages for the comments to load.

    Even when they’ve loaded the site frequently freezes. Or disconnects. Or substitutes a fucking insurance advert for what I’m in the middle of reading. Closinf the pop up means you have to start the whole process again.

    Don’t think the problem is my software, I’m not having this hassle on other sites.

  25. Wonk411 said,

    July 18, 2008 at 5:40 pm

    The comments page is exceptionally long. It will take several minutes to load (I went for coffee from 3% to 90%). Your patience will be rewarded.

  26. brainduck said,

    July 20, 2008 at 1:38 pm

    To Mr Coghill, or indeed anyone else who knows about this stuff,

    I’m in Bridgend. I have a couple of weeks during which I can wander round and actually measure EMF fields, maybe compare them to a place down the road that has lots of great big power lines & fewer suicides.

    What equipment would I need, and how would I go about making such measurements?


  27. Groinhammer said,

    July 23, 2008 at 12:33 pm

    This may be solution to all the woes caused by EM fields, radio frequencies, overhead cables, and clear up your dogs psoriasis to boot.
    Developed by Dr Yury Kronn (he is an expert dontcherknow) and is based on Quantum Physics principles.

  28. Sandy5 said,

    September 30, 2008 at 1:47 pm

    This is possibly a bit late given that the last comment was in August but Mr Coghill claims to be a member of IEEE. The IEEE Code of Ethics contains the following standards that members must adhere to (numbered as they appear in the Code):

    2) to avoid real or perceived conflicts of interest whenever possible, and to disclose them to affected parties when they do exist;
    3) to be honest and realistic in stating claims or estimates based on available data;
    7) to seek, accept, and offer honest criticism of technical work, to acknowledge and correct errors, and to credit properly the contributions of others;
    9) to avoid injuring others, their property, reputation, or employment by false or malicious action;

    I have included number 9 because of the distress that must have been caused to the families of the Bridgend suicide victims by the article in the Express.

    There are ten points overall in the IEEE Code of Ethics and it appears that Coghill has violated four of them. I would say that could be grounds for Member Conduct Complaint.

    Any members of IEEE interested in having a go at maintaining their organistations dignity could look at

  29. Lorne Trottier said,

    April 27, 2009 at 9:32 pm

    I’m sorry to be joining this thread so late. I have been a great admirer of the Bad Science web site. I have a particular interest in the area of EMF & Health – so I’ve read all the posts on eletrohypersensitivity. Your readers might be interested in a new web site I’ve created with a number of colleagues on this subject: The site is based on real science and provides a wealth of good information and references. The section on EHS has some interesting additional material – it also references Bad Science!

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  31. ajh1980 said,

    August 17, 2010 at 9:31 am

    I realise this thread is old news now but had to share this story.

    A good friend of mine’s kids attend a school in Plymouth right next to where a mobile phone company had erected a mast. The parents were up in arms and a public meeting was called at the school where a representative from the company agreed to take questions. The guy listened and quietly made notes for the best part of an hour as hysterical parents claimed that their children had suffered really bad headaches and were having trouble sleeping. The mast HAD to come down immediately before someone got cancer etc.

    After the mob had had their say, the rep politely pointed out that the mast wasn’t going to be switched on for another three months yet!!!