The Bewildering Case of Fraudulent Psychologist Diederik Stapel

Dr. Diederik A. Stapel was a respected psychology scientist at Tilburg University in the Netherlands, specialising in social psychology. Until lately he held the position of dean of social and behavioural sciences at the university. Among his areas of research, he studied interactions between self-image and the perceptions people hold of stimuli in the world surrounding them (e.g., other people, objects, advertisements). Or so he wanted us to believe. He was recently expelled from his university because it was revealled this month by an enquiry committee that over more than ten years he had manipulated and fabricated data in his studies, putting into doubt at least 30 published papers. Although it remains unclear whether he falsified data for his doctoral thesis at Amsterdam University (the data have been destroyed), he voluntarily returned his title to the university following the interim report and his own admission of committing fraud and deception in his research work.

What a shame for Stapel, what an embarrassment for a whole field of theory and research in psychology. But foremost Stapel betrayed colleagues who researched and published papers with him as well as the doctoral students he supposedly “guided” towards their degrees. Imagine how it feels to find out that research work you have done and published with a colleague you trusted could be tainted by his tempering with data and become unworthy of citation. It should also be uncomfortable for researchers who cited those papers in their own work, planned experiments based on his findings, or relied on these findings to develop theory and support their own arguments. The dismay for fresh doctorates could be even more disturbing. When a researcher deceives in the way Stapel has done he destroys not only his or her career but adversely affects the life and work of many others around him.

Some of the work in which Stapel was involved concern themes in consumer behaviour, marketing and advertising. Thus the deception carried out by Stapel is also suspect of inflicting on those fields. His work alone and with colleages directly investigated issues associated with consumer judgement and thinking; Assimilation-Contrast effects and information processing; advertising and self-image; beauty in advertising; product comparison and evaluation, and more.

Investigation into Stapel’s fraud so far suggests that already in early stages of his career he manipulated data he collected so as to “adapt” the data to hypotheses he wanted to support. Thereafter he has become more brazen and effectively fabricated data for his experiments altogether. Stapel may have been dishonest but certainly not stupid or incompetent. It does require numeric skills and good understanding of data in order to simulate datasets that seem as though they were innocently and genuinely collected. Yet, he may have not been so skilled or confident in his ability to conceal the fabrication as he reportedly almost always refused to submit raw data to the inspection of colleagues and graduate students. There is no guarantee that even if other researchers analysed data Stapel did provide they would succeed in uncovering anomalies or regularities indicative of fraud. Still it is baffling how this charade could have lasted for so many years: Have colleagues with whom Stapel co-operated not been part in the process of collecting, processing and analysing the data? Were they not in position to raise questions about the findings he brought in? Nonetheless, where criticism and doubts did come up towards him, Stapel allegedly made different excuses for his refusal, often arrogantly, and thus was able to fend them off .

Researchers are not immune from faults in human judgement such as using evidence selectively to support their prior beliefs or hypotheses. The blame is likely to be in the increasingly competitive culture of the academic system. In a response to International Herald Tribune (New-York Times), psychologist Jonathan Schooler (University of California) suggested that the problem is in a culture in academia that allows researchers to “spin their work” in a way that portrays a nicer picture of their findings than it really is. In an honest perspective contributed by  psychology professor Joseph P. Simmons (Wharton School) he conjures: “We know the general tendency of humans to draw the conclusions they want to draw… With findings we want to see, we ask, Can I believe this? With those we don’t, we ask: Must I believe this?” (IHT, 3 Nov. 2011).

The IHT tells of critics of current practices in psychological research, particularly the practice of keeping data in near secrecy, who claim that there should be greater demand from researchers to share data with other researchers in the field, allowing them to analyse the data and come to their own conclusions. I doubt that this will fix methodological malpractices in this field and may instead increase animosity among researchers. Researchers can and should raise questions and criticism about design and analytical methods their colleagues apply and the conclusions they draw; that is part of academic life. But if researchers do not trust the authenticity of data collected, then confidence in relying on published papers and books might be seriously damaged. Vigilance is always advised but is should be confined to circles within the academic institute and its departments and among colleagues working together. In the competitive climate that prevails in academia, perpetuated by the race for publishing papers (“publish or perish”), I do not think it is fair to blame researchers who are reluctant to submit datasets willingly to colleagues they are not truly familiar with. No one really wants to help others who might publish a paper that contradicts their own work. It is important, however, that researchers working together in a group or a research programme, not necessarily in the same research institute, exchange data and let more than one person analyse the data in parallel.

A particularly disturbing finding of the enquiry committee claims that Stapel may have jeopardised the theses of his doctoral students. It is assessed that between 12 and 14 of the 20 theses he supervised could be flawed because they relied on fabricated data he provided his students for analysis. Stapel gained the dubious title of “lord of the data” because of his insistence not to disclose how and where exactly the data were obtained and not to provide raw data (which raises the question, what kind of data did he provide students for analysis). Even if any of his research students suspected something was wrong with data they received, one would need to have clear evidence and the confidence to make allegations of fraud against one’s supervisor; it can put a doctoral student in a very difficult dilemma. Making things worse, Stapel used to threaten and insult students who dared to raise doubts about the data — one such student talking as a witness to the committee, its report says, was accused by Stapel of putting into doubt the latter’s well-established reputation as a top researcher. The student also complained of receiving hints from Stapel that the student’s aspirations as a young researcher could be compromised (Dutch

Stapel apparently intimidated also his colleagues who questioned his methods and his superior investigative talents. But eventually he came across three young researchers who either were smarter than he was or were fed up with his behaviour, probably both. They investigated one of his datasets and exposed his tactics to the head of Tilburg University (Dutch As Stapel continued to get away with his deception, he became more bold, and possibly too complacent at the end. Was he alert to the risks involved in his conduct or did he overlook them? Did he get tired of hiding his tracks? And did he expect or even want to get caught at some point in time? Stapel will have much time now to analyse his behaviour by introspection. And perhaps we will be able to find answers to such questions in a book that Staple will write himself.

Ron Ventura, Ph.D., (Marketing)


“New scandal is latest to taint psychology field”, Benedict Carey, The International Herald Tribune, 3 Nov., 2011, p.1+4.

“Five questions about: The Diederik Stapel affair”,, 2 Nov. 2011,

“Diederik Stapel: The lying Dutchman”, The Washington Post Online (Opinion), The Achenblog by Joel Achenbach, 1 Nov. 2011,

An entry on Diederik Stapel in Wikipedia (with a link to the original report of the enquiry committee in Dutch).

8 thoughts on “The Bewildering Case of Fraudulent Psychologist Diederik Stapel

  1. Someone necessarily help to make severely articles I’d state. That is the first time I frequented your web page and to this point? I surprised with the research you made to make this actual publish amazing. Great activity!

  2. Thanks for this post. I definitely agree with what you are saying. I have been talking about this subject a lot lately with my brother so hopefully this will get him to see my point of view. Fingers crossed!

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