09 May 2019

An update on our examination of the research of Dr. Nicolas Guéguen

(Joint post by Nick Brown and James Heathers)

It's now well over a year since we published our previous blog post about the work of Dr. Nicolas Guéguen. Things have moved on since then, so here is an update.

*** Note: We have received a reply from the Scientific Integrity Officer at the University of Rennes-2, Alexandre Serres. See the update of 2019-05-22 at the bottom of this post ***

We have seen two documents from the Scientific Integrity Officer at the University of Rennes-2, which appears to have been the institution charged with investigating the apparent problems in Dr. Guéguen's work. The first of these dates from June 2018 and is entitled (our translation from French), "Preliminary Investigation Report Regarding the Allegations of Fraud against Nicolas Guéguen".

It is unfortunate that we have been told that we are not entitled to disseminate this document further, as it is considerably more trenchant in its criticism of Dr. Guéguen's work than its successor, described in the next paragraph of this blog post. We would also like to stress that the title of this document is extremely inexact. We have not made, and do not make, any specific allegations of fraud, nor are any implied. The initial document that we released is entitled “A commentary on some articles by Dr. Nicolas Guéguen” and details a long series of inconsistencies in research methods, procedures, and data. The words “fraud” and “misconduct” do not appear in this document, nor in any of our communications with the people who helped with the investigation. We restrict ourselves to pointing out that results are “implausible” (p. 2) or that scenarios are “unlikely [to] be enacted in practice” (p. 31).

The origin of inconsistencies (be it typographical errors, inappropriate statistical methods, analytical mistakes, inappropriate data handling, misconduct, or something else) is also irrelevant to the outcome of any assessment of research. Any research object with a strong and obvious series of inconsistencies may be deemed too inaccurate to trust, irrespective of their source. In other words, the description of inconsistency makes no presumption about the source of that inconsistency.

The second document, entitled "Memorandum of Understanding Regarding the Allegations of Lack of Scientific Integrity Concerning Nicolas Guéguen", is dated October 2018, and became effective on 10 December 2018. It describes the outcome of a meeting held on 10 September 2018 between (1) Dr. Guéguen, (2) the above-mentioned Scientific Integrity Officer, (3) a representative from the University of Rennes-2 legal department, and (4) an external expert who was, according to the report, "contacted by [Brown and Heathers] at the start of their inquiry". (We are not quite certain who this last person is, although the list of candidates is quite short.)

The Memorandum of Understanding is, frankly, not very hard-hitting. Dr. Guéguen admits to some errors in his general approach to research, notably using the results of undergraduate fieldwork projects as the basis of his articles, and he agrees that within three months of the date of effect of the report, he will retract two articles: "High heels increase women's attractiveness" in Archives of Sexual Behavior (J1) and "Color and women hitchhikers’ attractiveness: Gentlemen drivers prefer red" in Color Research and Application (J2). Recall that our original report into problems with Dr. Guéguen's research listed severe deficiencies in 10 articles; the other eight are barely mentioned.

On the question of Dr. Guéguen's use of undergraduate fieldwork: We were contacted in November 2018 by a former student from Dr. Guéguen's class, who gave us some interesting information. Here are a few highlights of what this person told us (our translation from French):
I was a student on an undergraduate course in <a social science field>. ... The university where Dr. Guéguen teaches has no psychology department. ... As part of an introductory class entitled "Methodology of the social sciences", we had to carry out a field study. ... This class was poorly integrated with the rest of the course, which had nothing to do with psychology. As a result, most of the students were not very interested in this class. Plus, we were fresh out of high school, and most of us knew nothing about statistics. Because we worked without any supervision, yet the class was graded, many students simply invented their data. I can state formally that I personally fabricated an entire experiment, and I know that many others did so too. ... At no point did Dr. Guéguen suggest to us that our results might be published.
Our correspondent also sent us an example of a report of one of these undergraduate field studies. This report had been distributed to the class by Dr. Guéguen himself as an example of good work by past students, and has obvious similarities to his 2015 article "Women’s hairstyle and men’s behavior: A field experiment". It was written by a student workgroup from such an undergraduate class, who claimed to have conducted similar tests on passers-by; the most impressive of the three sets of results (on page 7 of the report) was what appeared in the published article. The published version also contains some embellishments to the experimental procedure; for example, the article states that the confederate walked "in the same direction as the participant about three meters away" (p. 638), a detail that is not present in the original report by the students. A close reading of the report, combined with our correspondent's comments about the extent of admitted fabrication of data by the students, leads us to question whether the field experiments were carried out as described (for example, it is claimed that the three students tested 270 participants between them in a single afternoon, which is extraordinarily fast progress for this type of fieldwork).

(As we mentioned in our December 2017 blog post, at one point in our investigation Dr. Guéguen sent us, via the French Psychological Society, a collection of 25 reports of field work carried out by his students. None of these corresponded to any of the articles that we critiqued. Presumably he could have sent us the report that appears to have become the article "Women’s hairstyle and men’s behavior: A field experiment", but apparently he chose not to do so. Note also that the Memorandum of Understanding does not list this article as one that Dr. Guéguen is required to retract.)

We have made a number of documents available at https://osf.io/98nzj/, as follows:
  • "20190509 Annotated Guéguen report and response.pdf" will probably be of most relevance to non French-speaking readers. It contains the most relevant paragraphs of the Memorandum of Understanding, in French and (our translation) English, accompanied by our responses in English, which then became the basis of our formal response.
  • "Protocole d'accord_NG_2018-11-29.pdf" is the original "Memorandum of Understanding" document, in French.
  • "20181211 Réponse Brown-Heathers au protocole d'accord.pdf" is our formal response, in French, to the "Summary" document.
  • "20190425 NB-JH analysis of Gueguen articles.pdf" is the latest version of our original report into the problems we found in 10 articles by Dr. Guéguen.
  • "Hairstyle report.pdf" is the student report of the fieldwork (in French) with a strong similarity to the article "Women’s hairstyle and men’s behavior: A field experiment", redacted to remove the names of the authors.
Alert readers will have noted that almost five months have elapsed since we wrote our response to the "Memorandum of Understanding" document. We have not commented publicly since then, because we were planning to publish this blog post in response to the first retraction of one of Dr. Guéguen's articles, which could either have been one that he was required to retract by the agreement, or one from another journal. (We are aware that at least two other journals, J3 and J4, are actively investigating multiple articles by Dr. Guéguen that they published.)

However, our patience has now run out. The two articles that Dr. Guéguen was required to retract are still untouched on the respective journals' websites, and our e-mails to the editors of those journals asking if they have received a request to retract the articles have gone unanswered (i.e., we haven't even been told to mind our own business) after several weeks and a reminder. No other journal has yet taken any action in the form of a retraction, correction, or expression of concern.

All of this leaves us dissatisfied. The Memorandum of Understanding notes on page 5 that Dr. Guéguen has 336 articles on ResearchGate published between 1999 and 2017. We have read approximately 40 of these articles, and we have concerns about the plausibility of the methods and results in a very large proportion of those. Were this affair to be considered closed after the retraction of just two articles—not including one that seems to have been published without attribution from the work of the author’s own students—it seems to us that this would leave a substantial amount of serious inconsistencies unresolved.

Accordingly, we feel it would be prudent for the relevant editors of journals in psychology, marketing, consumer behaviour, and related disciplines to take action. In light of what we now know about the methods deployed to collect the student project data, we do not think it would be excessive for every article by Dr. Guéguen to be critically re-examined by one or more external reviewers.

[ Update 2019-05-09 15:03 UTC: An updated version of our comments on the Memorandum of Understanding was uploaded to fix some minor errors, and the filename listed here was changed to reflect that. ]

[ Update 2019-05-09 18:51 UTC: Fixed a couple of typos. Thanks to Jordan Anaya. ]

[ Update 2019-05-10 16:33 UTC: Fixed a couple of typos and stylistic errors. ]

[ Update 2019-05-22 15:51 UTC:
We have received a reply to our post from Alexandre Serres, who is the Scientific Integrity Officer at the University of Rennes-2. This took the form of a 3-page document (in both French and English versions) that did not fit into the comments box of a Blogger.com post, so we have made these two versions available at our OSF page. The filenames are "Réponse_billet de Brown et Heathers_2019-05-20.pdf" (in French) and "Réponse_billet de Brown et Heathers_2019-05-20 EN" (in English).

We have also added a document that was created by the university before the inquiry took place (filename "Procédure_traitement des allégations de fraude_Univ Rennes2_2018-01-31.pdf"), which established the ground rules and procedural framework for the inquiry into Dr. Guéguen's research.

We thank Alexandre Serres for these clarifications, and would only add that, while we are disappointed in the outcome of the process in terms of the very limited impact that it seems to have had on the problems that we identified in the public literature, we do not have any specific criticisms of the way in which the procedure was carried out.


  1. Goodness, Dr. Guéguen seems to have produced a shocking number of bad studies. So many that I cannot even read all of them. So, thanks for your work. But, I am wondering: if you could choose only one as the *worst* example, which would you vote for? I really like to give my psychology students an article & ask them to pick it apart, looking for mistakes & problems. I am having trouble narrowing the list down when it comes to this dude...

    1. It's really hard to choose one, but I think that http://dx.doi.org/10.1002/col.20651 will keep your students busy. Just get them to think about how long the study must have taken. This is one of the ten articles that we covered in the report that is linked to in our previous blog post.