The old adage that if something seems too good to be true, it probably is was never more aptly demonstrated than in the case of disgraced psychologist Diederik Stapel.
Tilburg University’s former professor of cognitive social psychology and dean of its School of Social and Behavioural Sciences was regarded as one of Europe’s top researchers in the field. He made a name for himself with a series of eye-catching claims: the presence of wine glasses improves table manners; messy environments promote discrimination; and, most recently, meat eaters are more antisocial than vegetarians.
But his star fell in early September when he was first suspended and then sacked by Tilburg for fabricating data, a charge he did not deny. His disgrace was complete when, earlier this month, he voluntarily returned his 1997 PhD to the University of Amsterdam, declaring in a letter to the institution that his conduct “does not fit with the duties associated with a doctorate”.
An Amsterdam investigative committee had previously found no evidence of fraud in his thesis. But a panel set up by Tilburg to investigate the extent of Mr Stapel’s misdemeanours, which published its interim report last month, recommended that his PhD be revoked on the grounds of “exceptional academically unworthy conduct”.
Mr Stapel volunteered a list of his fraudulent papers to the panel, chaired by W.J.M. Levelt, former president of the Royal Netherlands Academy of Arts and Sciences: the report says they number “several dozen”, dating back to at least 2004.
Exactly how many of Mr Stapel’s 250 articles, book chapters and conference proceedings are compromised will not be known until a final report is published, bringing together the findings of the Tilburg and Amsterdam inquiries, as well as one by another of Mr Stapel’s previous employers, the University of Groningen. This will take several months.
According to Tilburg’s interim report, Mr Stapel’s typical modus operandi was to team up with a student or colleague to design a study to test one of the collaborator’s own hypotheses.
He would then purport to carry out the study and process the data by himself or with an unknown assistant. He then provided the processed data file - which, in reality, was often entirely fabricated - to the collaborator for analysis.
One student who persistently requested access to the raw data was accused by the disgraced scholar of “calling his capacities and experience as a renowned professor into question”. But collaborators typically regarded Mr Stapel’s processing as a “service”, and the “close bonds” he often formed with them tended to minimise their suspicion.
“The last thing that colleagues, staff and students would suspect is that, of all people, the department’s scientific star, and faculty dean, would systematically betray that trust,” the report says.
Observations by colleagues that Mr Stapel’s data were “too good to be true” were meant as a compliment: “People accepted, if they even attempted to replicate the results for themselves, that they had failed because they lacked [his] skill.”
It was not until August that Mr Stapel was finally exposed by three of his PhD students. Since none of his students “could or should” have been previously aware of any data tampering, their doctorates will stand. But the panel notes the “element of stigmatisation” that may persist long into their careers and deems this reasonable grounds for a criminal fraud investigation.
The report also recommends giving future PhD candidates in psychology at least two supervisors and requiring them to collect and analyse their own data.
In his response, included in the report, Mr Stapel speaks of his “sense of dismay and shame” and apologises for the suffering he has caused. But he does not “identify with” the report’s depictions of “a man who has attempted to use young researchers for his own gain”.
The report also laments the damage done by Mr Stapel to the reputation of social psychology and calls on the discipline to place more emphasis on the replication of results.
“Replication and the falsification of hypotheses are cornerstones of science. Mr Stapel’s verification factory should have aroused great mistrust among colleagues, peers and journals,” it says.
But it also notes that psychology researchers’ reluctance to release their raw data makes replication and further analysis difficult.
Mark Davies, dean of the School of Psychology at the University of East London and chair of the Joint Committee for Psychology in Higher Education, pointed out that ethical and data-protection considerations meant it was impossible to release sensitive and confidential data without subjects’ consent.
“This does not mean that access cannot be granted, but it has to be carefully managed,” he said.
He added that the emphasis on original research created by research assessment regimes discouraged scholars from spending time on attempts to replicate others’ results.
But he said “deference without challenge” was uncommon in the UK. In his view, the Stapel case demonstrated very little, “apart from confirming that individuals who enter psychology are as vulnerable to misdemeanour as any other group of professionals”.
Stephen Reicher, a professor in the University of St Andrews’ School of Psychology, remembered tutoring an “immensely enthusiastic, energetic, cultured and idealistic” Mr Stapel when he was an Erasmus student at the University of Exeter in the 1990s. For Professor Reicher, his “path to corruption” was partly a symptom of the “commodification” of the academy and the pressure to publish.
“Publication becomes an end in itself. You don’t have to believe in what you found, you just have to get it out,” he said. “You become more Machiavellian in how you [do that]: it is a slippery slope.”
Fabrizio Butera, president of the European Association of Social Psychology and professor of social psychology at the University of Lausanne, agreed that raw data should be made available and hoped the rise of open-access journals would facilitate this.
He added that psychology’s reputation was “under fire” and he expressed concerns that this could demoralise young researchers in the field. But he rejected the suggestion made by some media coverage that the scandal revealed that psychology had a particular problem with its research methodology or its approach to open data.
“Many scientific disciplines present much higher rates of scientific misconduct; it is time for psychology to join the other disciplines in efforts to reduce this societal problem,” he said.
Daniel Wigboldus, chair of the department of social and cultural psychology at Radboud University Nijmegen, urged his peers to take the Tilburg report’s recommendations seriously, but also denied that it revealed any fundamental problems with the discipline.
“Psychology textbooks are full of research that has been replicated by different researchers in different labs across the world,” he said. “The way Diederik Stapel worked is not representative of our field whatsoever.”