The University of Amsterdam has requested another retraction for a prominent social psychologist, after reviewing the dissertations he supervised while at the university.
The university made the announcement this week after reviewing the theses supervised by Jens Förster, whose own work has been subject to considerable scrutiny.
The results of this investigation come more than two years after an initial probe into Förster’s work, which found several of his papers likely contained unreliable data; three of these papers have been retracted and four have received expressions of concern. Förster, who recently left his position at Ruhr-Universität Bochum in Germany to start a private psychology practice, has always maintained that he did not manipulate his data. In 2015, he turned down a professorship, citing the toll the investigation had taken.
The statisticians who conducted the recent analysis—Letty Koopman, Frans J. Oort and Chris A.J. Klaassen—found “no evidence” of statistical issues in three of the four theses. However, the fourth thesis by Marleen Gillebaart, now an assistant professor at Utrecht University in The Netherlands, had “a number of peculiarities.”
According to the 43-page report, the statisticians found that two chapters in the thesis, which were published as a 2012 Journal of Experimental Psychology paper, showed “several inconsistencies and unexpected phenomena,” which “cast doubt on the validity of the results:”
As there does not seem to be any possible substantive explanation for the combination of peculiarities in the data, we suspect that mistakes have been made in the (pre-)processing of the data.
The university determined that Förster, not Gillebaart, was responsible for data issues:
The experts conclude that the data used by Gillebaart were collected and processed by Jens Förster or by one or more others under his responsibility. Only after processing the data, Jens Förster provided the data to Gillebaart, on the basis of which she wrote an article. Hence Gillebaart cannot be blamed for the data collection and data processing.
The paper, “Mere exposure revisited: the influence of growth versus security cues on evaluations of novel and familiar stimuli,” has been cited 10 times since 2012, according to Clarivate Analytics’ Web of Science.
Given the “strong evidence of low scientific veracity” in the 2012 paper, the university says it has asked the Journal of Experimental Psychology to retract the article.
We contacted the journal; a spokesperson for the American Psychological Association, which publishes the journal, told us:
As we only received the request yesterday, we have not had a chance to reach a decision as yet.
Nick Brown, PhD student at the University of Groningen who has also flagged statistical issues in papers by Cornell food researcher Brian Wansink, tweeted that he and James Heathers reported this 2012 paper to the journal seven months ago, and had “a fine collection of cricket sounds.”
Gillebaart told us that she is aware of the university’s requests and awaits the journal’s decision, but reiterated the report’s conclusion that “the co-authors should not be held responsible” for the data reported in the 2012 paper.
We asked the university if Gillebaart’s PhD was at risk if the paper was retracted; a spokesperson referred us to the university’s statement:
…the Doctorate Board of the University of Amsterdam concludes that the thesis containing the two chapters itself is not in question.
This isn’t the first time a professor has supplied a graduate student with unreliable data, instead of the other way around: social psychologist Diederik Stapel—who, unlike Förster, was found guilty of fraud— did the same.
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