18 December 2017

A review of the research of Dr. Nicolas Guéguen

Over the last couple of weeks, James Heathers and I have been blogging about some rather strange articles by Dr. Nicolas Guéguen, of the Université Bretagne-Sud in France.  In this joint post, we want to summarise the apparent issues that we have identified in this researcher’s output.  Some of the points we make here have already been touched on (or more) in an excellent article by Cathleen OGrady at Ars Technica.

There is a lot to read

The first thing one notices in looking at his Google Scholar record is that Dr. Guéguen is a remarkably prolific researcher.  He regularly publishes 10 or more sole-authored empirical articles per year (this total reached 20 in 2015), many of which include extensive fieldwork and the collection of data from large numbers (sometimes even thousands) of participants. Yet, none of the many research assistants and other junior collaborators who must have been involved in these projects ever seem to be included as co-authors, or even have their names mentioned; indeed, we have yet to see an Acknowledgments section in any sole-authored article by Dr. Guéguen.  This seems unusual, especially given that in some cases the data collection process must have required the investment of heroic amounts of the confederates’ time.

Much of Dr. Guéguen's research focuses on human relationships, in what one might euphemistically term a rather "old-fashioned" way.  You can get a flavour of his research interests by browsing through his Google Scholar profile.  As well as the articles we have blogged about, he has published research on such vital topics as whether women with larger breasts get more invitations to dance in nightclubs (they do), whether women are more likely to give their phone number to a man if asked while walking near a flower shop (they are), and whether a male bus driver is more likely to let a woman (but not a man) ride the bus for free if she touches him (we’ll let you guess the answer to this one).  One might call it “Benny Hill research”, although Dr. Guéguen has also published plenty of articles on other lightweight pop-social-psychology topics such as consumer behaviour in restaurants (does that sound familiar?) that do not immediately conjure up images of sexual stereotypes.

Neither Dr. Guéguen’s theories, nor his experimental designs, generally present any great intellectual challenges.  However, despite their simplicity, and the almost trivial nature of the manipulations, his studies often produce effect sizes of the kind more normally associated with the use of domestic cleaning products against germs. Many of the studies also seem to be run on a production line system, with almost every combination of independent and dependent variables being tested (something that was noted by Hans van Maanen in the Dutch newspaper De Volkskrant as far back as 2012).  For example, waitresses get more tips if they have blonde hair or use make-up or wear a red t-shirt, but women wearing red also find it easier to hitch a ride, as do women with blonde hair or larger breasts.  Those same women with blonde hair or larger breasts also get asked to dance more in nightclubs. As well as earning her more tips if she is a waitress, using make-up also makes a woman more likely to be approached by a man in a bar, although her choice to wear make-up might reflect the fact that she is near ovulation, at which point she is also more likely to accept that invitation to dance; and so it goes, round and round.

It seems that some of this research is actually taken quite seriously by some psychologists.  For example, it is cited in recent work by Andrew Elliot and colleagues at the University of Rochester that claims to show that women wear red clothes as a sexual signal (thus also providing a piece of Dr. Guéguen’s IV/DV combination bingo card that would otherwise have been missing). The skeptical psychologist Dr. Richard Wiseman also seems to be something of a fan of Guéguen's work; for example, in his 2009 book 59 Seconds: Think a Little, Change a Lot, Wiseman noted that "Nicolas Guéguen has spent his career investigating some of the more unusual aspects of everyday life, and perhaps none is more unusual than his groundbreaking work on breasts", and he also cited Guéguen several times in his 2013 book The As If Principle.

And of course, as is common for research with themes of sexual attraction and other aspects of everyday human behaviour, these results readily find their way into the popular media, such as the Daily Mail (women are more likely to give their phone number to a man who is carrying a guitar), the Guardian (people drink more in bars with louder music), The Atlantic (men think that women wearing red are more likely to be interested in sex) and the New York Times (customers spend more money in a restaurant if it smells of lavender).

Beyond a joke

But our concerns go well beyond the apparent borderline teenage sexism that seems to characterise much of this research.  A far bigger scientific problem is the combination of extraordinary effect sizes, remarkably high (in some cases, 100%) response rates among participants recruited in the street (cf. this study, where every single one of the 500 young female participants who were intercepted in the street agreed to reveal their age to the researchers, and every single one of them turned out to be aged between 18 and 25), other obvious logistical obstacles, and the large number of statistical errors or mathematically impossible results reported in many of the analyses.

We also have some concerns about the ethicality of some of Dr. Guéguen’s field experiments.  For example, in these two studies, his male confederates asked other men how likely it was that a female confederate would have sex with them on a first date, which might be a suitable topic for bar-room banter among friends but appears to us to be somewhat intrusive.  In another study, women participants were secretly filmed from behind with the resulting footage being shown to male observers who rated the “sexiness” of the women’s gait (in order to test the theory that women might walk “more sexily” in front of men when they are ovulating; again, readers may not be totally surprised to learn that this is what was found). In this study, the debriefing procedure for the young female participants involved handing them a card with the principal investigator’s personal phone number; this procedure was “refined” in another study, where participants who had agreed to give their phone number to an attractive male confederate were called back, although it is not entirely clear by whom. (John Sakaluk has pointed out that there may also be issues around how these women’s telephone numbers were recorded and stored.)

It is unclear from the studies presented that any of these protocols received individual ethical approval, as study-specific details from an IRB are not offered. Steps to mitigate potential harms/dangers are not mentioned, even though in several cases data collection could have been problematic, with confederates dressing deliberately provocatively in bars and so on. Ethical approval is mentioned only occasionally, usually accompanied by the reference number “CRPCC-LESTIC EA 1285”.  This might look like an IRB approval code of some kind, but in fact it is just the French national science administration’s identification code for Dr. Guéguen’s own laboratory.

It is also noteworthy that none of the articles we have read mention any form of funding. Sometimes, however, the expenses must have been substantial.  In this study (hat tip to Harry Manley for spotting it), 99 confederates stood outside bars and administered breathalyser tests to 1,965 customers as they left.  Even though the breathalyser device that was used is a basic model that sells for €29.95, it seems that at least 21 of them were required; plus, as the “Accessories” tab of that page shows, the standard retail price of the sterile mouthpieces (one of which was used per participant) before they were discontinued was €4.45 per 10, meaning that the total cash outlay for this study would have been in the region of €1500.  One would have thought that a laboratory that could afford to pay for that out of petty cash for a single study could also pick up the tab in a nightclub from time to time.

This has been quite the saga

It is almost exactly two years to the day since we started to put together an extensive analysis (over 15,000 words) focused on 10 sole-authored articles by Dr. Guéguen, which we then sent to the French Psychological Society (SFP). The SFP’s research department agreed that we had identified a number of issues that required an answer and asked Dr. Guéguen for his comments. Neither they nor we have received any coherent response in the interim, even though it would take just a few minutes to produce any of the following: (a) the names and contact details of any of the confederates, (b) the field notes that were made during data collection, (c) the e-mails that were presumably sent to coordinate the field work, (d) administrative details such as insurance for the confederates and reimbursement of expenses, (e) minutes of ethics committee meetings, etc.

At one point Dr. Guéguen claimed that he was too busy looking after a sick relative to provide a response, circumstances which did not prevent him from publishing a steady stream of further articles in the meantime.  In the autumn of 2016, he sent the SFP a physical file (about 500 sheets of A4 paper) containing 25 reports of field experiments that had been conducted by his undergraduates, none of which had any relevance to the questions that we had asked.  In the summer of 2017, Dr. Guéguen finally provided the SFP with a series of half-hearted responses to our questions, but these systematically failed to address any of the specific issues that we had raised.  For example, in answer to our questions about funding, Dr. Guéguen seemed to suggest that his student confederates either pay all of their out-of-pocket expenses themselves, or otherwise regularly improvise solutions to avoid incurring those expenses, such as by having a friend who works at each of the nightclubs that they visit and who can get them in for free.

We want to offer our thanks here to the officials at the SFP who spent 18 months attempting to get Dr. Guéguen to accept his responsibilities as a scientist and respond to our requests for information. They have indicated to us that there is nothing more that they can do in their role as intermediary, so we have decided to bring these issues to the attention of the broader scientific community.

Hence, this post should be regarded as a reiteration of our request for Dr. Guéguen to provide concrete answers to the questions that we have raised. It should be very easy to provide at least some evidence to back up his remarkable claims, and to explain how he was able to conduct such a huge volume of research with no apparent funding, using confederates who worked for hours or days on end with no reward, and obtain remarkable effect sizes from generally minor social priming or related interventions, while committing so many statistical errors and reporting so many improbable results.

Further reading

We have made a copy of the current state of our analysis of 10 articles by Dr. Guéguen available here, along with his replies (which are written in French).  For completeness, that folder also includes the original version of our analysis that we sent to the SFP in late 2015, since that is the version to which Dr. Guéguen eventually replied.  The differences between the versions are minor, but they include the removal of one or two points where we no longer believe that our original analysis made a particularly strong case. We also now have a better understanding of how to report some of the issues that we raise, partly because we have more experience with the application of tools such as GRIM and SPRITE.

Despite its length (around 50 pages), we hope that interested readers will find our analysis to be a reasonably digestible introduction to the problems with this research.  Most of the original journal articles are behind paywalls, but none are so obscure that they cannot be obtained from standard University subscriptions.

Nick Brown
James Heathers


  1. Dear Nick and James,

    Thank you for your huge work in questionning/correcting science.

    A few clarifications/comments.

    - Regarding the ethical approval, I don't know how familiar you are with how French Universities work, even if one of you is living in France, but it is not a requirement for French researchers to ask for ethical approval for non-interventional / non medical research. As a matter of fact, ethical comittees outside of medical research, are pretty rare. As it is sometimes required by some outlet for publication, I heard that some researchers would indicate that their lab provided said approval (which is probably not exactly the truth).

    - I don't exactly know how Nicolas Guéguen works, but I think that his students (hundreds of 1st or 2nd year students) have to conduct an "experiment" as an assignment for some of his class. I can understand why it might be hard to track down everyone of them to give you their contacts.

    My point is not to excuse Guéguen for his way of doing research. I don't know him personally. I am not implying that his behavior is acceptable, or that his research is not ethically questionnable. I just wanted to maybe clarify some points.

    The usual reaction to Guéguen's research among my colleagues is often to laugh at it, and to move on. Until I recently heard James' comment on Cuckoo Science (in the excellent Everything Hertz podcast), I didn't get why one would spend so much time to analyze and try to understand such laughable and un-important research. Thank you again for opening my eyes.

    Un chercheur français.

  2. Salut Anonymous,

    I don't think that there is any question that Guéguen sends a lot of students out to do field work. I've read a bunch of their reports and they look like you'd expect first-year undergraduate fieldwork reports to look like, including all the problems you'd expect when they design their own measures and try to do their own statistics without, in some cases, apparently knowing that to compare means one needs a measure of the variance.

    The studies described in the articles, though, mostly describe fieldwork on another scale. Often we are talking about many consecutive full days of work. If 99 confederates visit 21 bars with €1500 worth of test equipment, that's not something they put together in their WhatsApp group. There will surely be traces of the e-mails that were sent as part of the coordination of that study, and of many of the 10 that appeared in our long document. Yet after two years we have not been offered the chance to see a single piece of concrete evidence about any of these studies.

    As for the ethical approval: many of the questions we have are not so much about avoiding Milgram/Stanford-type abuses, as basic security concerns for the welfare of the confederates. There are certainly a number of questions that we would expect to be asked about things like insurance --- especially in France, where in my experience "et s'il arrive quelque chose ?" is usually the first question whenever more than two people try to organise pretty much anything --- before people are sent out to conduct research in the lab's name.


  3. Great post.

    "In the autumn of 2016, he sent the SFP a physical file (about 500 sheets of A4 paper) containing 25 reports of field experiments that had been conducted by his undergraduates, none of which had any relevance to the questions that we had asked."

    Had any of these undergraduate experiments ended up getting published?

    1. Not as far as I know. They looked like typical undergraduate projects. About half of them had obvious statistical errors. In a couple of cases the authors had apparently never heard of a standard deviation. Maybe two or three of them would be worth writing up as a poster.

  4. So we have a researcher who supervises dozens of undergraduate projects, which he keeps records of, but never writes any of them up.

    He also carries out dozens of other projects, which he does write up, but has no records of.


  5. Yeah, that's the thing. The kind of logistical organisation required to run most of these studies leaves a lot of traces, whether on paper or e-mail systems. After two years we haven't seen a single name of a confederate. In fact we haven't seen a singly record of any kind, even in redacted form (not that it would seem necessary for the confederates to be anonymised). I wonder if any of the confederates will come forward?

  6. Bonjour !
    Thanks for your great work on this subject.
    I have never heard of Nicolas Gueguen before le Monde.fr published an article about your research and the controverse you pointed out.
    It is such a shame that a few "so called" scientists discredit the French public research community.

  7. Hi Nick,

    thanks for providing the transcripts, however, the form does not allow to copy and paste it correctly, e.g., in a translation form from google. Is there any chance to provide another transcript, e.g., on a website?
    Thanks in advance,


    1. I hope I've understood your request properly:
      - For the "October 2016" reply I didn't type up a transcript, for various reasons including the fact that the scientific content is very low.
      - For "July 2017", you should be able to copy and paste from the RTF form of the document, or export that to a TXT file.

      Please let me know by e-mail if I haven't fully understood the problem here.


  8. Ah, I am sorry,I tried to copy it directly from the dropbox instead of downloading it before ;-)

    Well, I had a look on several other papers from this psychologist and found always the same pattern: Always trivial research questions (sometimes with only his papers as theoretical background), round participants numbers and a very big sample size, huge effect sizes, silly stories for the manipulation and implemetation of the research, fancy journal names that noone ever heard about, and so on. And publications of the researchers from his lab which are sometimes the first author show the same pattern. Perhaps the whole lab is rotten? :-D

  9. Hi Nick
    Going out on a limb here.... could it be that he uses confederates which are singularily female, blond, big-breasted and wear a red shirt/dress to use one "encounter" to score for several outcomes in parallel?

    O.k that bit about that hitchhiker "encounter" on weekends at that tourism spot doesn't lend itself for too many parallel outcomes but those night club / bar "encounters" do seem to allow for that?

    Cheers, Oliver

    1. The articles tends to describe, in considerable detail, the precautions that were taken to ensure that there were no confounding factors; for example, if the manipulation is the t-shirt colour, the women will typically be reported as all being the same (average) height, having the same bra size, the same colour (brown) hair, etc. Everything possible is done to allow the results to be expressed in terms of a 2x2 or even 2x1 contingency table, or a simple one- or two-way ANOVA.

      Of course, this reporting might be inadvertently totally wrong in every case, like Brian Wansink's numerous inadvertent reporting errors. Maybe that's just the price one pays for doing cutting-edge research at the frontiers of human experience. But I don't think it's our job to work that out.

  10. It seems to me that it is likely that some or several of these 'confederates' (likely students) are in the meanwhile aware that Le Monde has publised an article about this issue (http://mobile.lemonde.fr/sciences/article/2017/12/19/les-methodes-du-chercheur-nicolas-gueguensur-la-sellette_5231708_1650684.html ). It also seems to me that it is not unlikely that regional and/or local journals and/or other news outlets have in the meanwhile also published about this issue.

    So are there in the meanwhile already one or more of these 'confederates' (likely students) who have contacted Nick and/or others and/or who have been able to locate traces (on the internet) about these studies?

    I fully agree with the view of Nick that such large-scale field experiments need alot of organisation (by e-mail etc.). I also don't exclude that there are for example items like digital newsletters about these projects.

    So why is it impossible to locate until now any of these traces?

    There is towards my opinion a strong similarity with the existence of several psychological experiments carried out / organized by the German psychologist Jens Förster. No traces and no other details. Jens Förster is always invariably claiming that he has thrown away all the raw research data and all the other details. See also a recent verdict by the University of Amsterdam (UVA, The Netherlands), see http://www.uva.nl/en/content/news/news/2017/12/dissertations-supervised-by-jens-forster-reviewed.html?origin

    "Gillebaart et al. (2012) shows strong evidence of low scientific veracity of its results. (...) the underlying data was collected under the responsibility of Förster".

    1. Klaas: If any of Dr. Guéguen's confederates come forward to report having taken part in the studies that we covered in our dossier, I will post an update here.

  11. Thanks. Paper #10 (Risk Taking and Women’s Menstrual
    Cycle: Near Ovulation, Women Avoid a Doubtful Man) was accepted on the same day when it was received. I am unable to locate in this paper any details about an ethical approval.

  12. Are there any updates about the Gueguen-Investigation? I searched the internet but I could not find anything. Interestingly Gueguen and some of his research fellows seem to have stopped publishing studies. So what is going on?

    1. I have heard suggestions that there are investigations under way at Dr Guéguen's university and that some of the journals that published his studies may also be looking into these matters. But I haven't heard anything official all this year.

    2. Ok. Thank you very much. :)

  13. Are there any news about this story?

  14. No - see my reply to the previous comment from 1 October 2018. If I hear anything that I can share (so far I haven't even heard anything that I can't share!), I'll let you know.

  15. According to the Website of the UBS, Gueguen ist still the director of his lab: http://www.univ-ubs.fr/fr/universite-bretagne-sud/organisation-2/direction.html
    however, it seems that there has been no research "output" from him over the last year...