This past September, a Dutch psychologist was suspended from his post after evidence surfaced that he had committed academic fraud on an extensive scale.
Diederik Stapel, a leading professor of social psychology in the Netherlands, reportedly fabricated data sets in “several dozen” studies since at least 2004. The suspension came after three junior researchers approached the head of Stapel’s department with concerns about the integrity of his data. Three other researchers had previously raised their concerns, but they were never followed up.

Tilburg University in the Netherlands, where Stapel had held appointment since 2007, formed a committee to investigate the accusations. The universities of Amsterdam and Groningen, where he had previously held appointments, did the same. The committee at Tilburg, chaired by Prof. Willem Levelt, released an interim report describing the extent and methods of Stapel’s fraud and providing recommendations for future action.

Stapel has been a co-author on more than 150 papers and supervised the theses of several PhD students. It is not clear exactly how many of these papers might be tainted by the fraud, but the Levelt committee identified at least several dozen. “To the best of our knowledge, misconduct of this kind by a full professor in [Stapel’s] position is unprecedented,” said the committee in its report. At least three of Stapel’s doctoral students have unknowingly based parts of their dissertations on fabricated data. The committee found no evidence that anyone else was complicit in the fraud.

The Levelt report details the methods Stapel used in his fabrications.
Stapel would set off to a (fictitious) school and the research assistants who were to aid him turned out to be fictitious as well. The raw data, supposedly coded by Stapel’s assistants at the experiment sites, was never seen by anyone other than Stapel. In other cases, when a hypothesis was not confirmed, Stapel would massage the data until it gave a more favourable result.

Stapel did not consent to an interview with the Levelt committee but did send a brief letter responding to their report. “I have read the report with a sense of dismay and shame,” he said, adding, “I must emphasize that the errors I have made were not motivated by self-interest.” He later published a written statement, claiming that he felt pressure to “score points, to publish, to always have to be better.”

He did not take issue with any of the report’s factual content, but stated that he did not identify with “the picture that has been sketched of a man who has attempted to use young researchers for his own gain,” and reaffirmed commitment to his colleagues and the field of social psychology.

Stapel’s ruse was able to survive so long, the report says, in part due to its “unthinkable” extent. But the scheme’s continued success was characterized as a “failure of scientific criticism.” Stapel never disclosed the locations of the schools where he claimed to be supervising the experiments, and no one ever saw the completed questionnaires. His data was “too good to be true,” almost always confirming his hypothesis in ways that were statistically improbable, lacking the statistical noise that is characteristic of psychological experiments. Researchers who failed to replicate Stapel’s results assumed that it was because they lacked his experimental skill.

A tradition of keeping raw data secret, in psychology as well as other sciences, was also blamed. “We have the technology to share data and publish our initial hypotheses, and now’s the time,” Jonathan Schooler, a psychologist at the University of California, Santa Barbara, told the New York Times. “It would clean up the field’s act in a very big way.”

The Levelt report closes with several recommendations for future action. It calls for further education of PhD students in academic integrity, more transparency from journal publishers, and the establishment of replication as “part of the basic instruments of the discipline.” It recommends that the university file a criminal report with the Dutch Public Prosecution Service, and invites investigation into the possibility of revoking Stapel’s doctorate for “exceptional academically unworthy conduct.”

Perhaps in a move to forestall further embarrassment, on Nov. 10 Stapel freely relinquished his doctorate obtained from the University of Amsterdam.

illustration by tiff bartel