Who is Yannick Griep, the fraudulent associate professor in psychology who was summarily dismissed? Colleagues paint a picture of a charismatic and ambitious researcher. But also of someone with a blunt and unreliable side.

“This is why everyone steals office supplies from work – including you.” That is the title of an article psychologist Yannick Griep wrote for the popular science website The Conversation in 2018. Seven years later, the associate professor in Work and Organizational Psychology was dismissed because he himself appeared to have stolen from his work. An observant Radboud employee who processes expense claims noticed that an invoice for participant reimbursements submitted by Griep (amounting to €2,500) partly used a different font. Upon closer inspection, it turned out that Griep had manipulated it, and he was summarily dismissed at the end of 2024. He challenged the dismissal legally, which resulted in a settlement (a termination agreement) with Radboud University.

His departure hit the department like a bomb. A former colleague: “No one saw it coming, I think he didn’t either.” What did not help was that no explanation was given by management about the underlying reason. As a result, it remained unclear for a long time what the dismissal meant for his academic activities. Only a year later, there was a presentation for a limited group of direct colleagues in which the manipulated invoice was shown as further explanation.

For some, that fake invoice was a reason to further examine the reliability of Griep’s scientific work. It soon emerged that a recent study contained problems: roughly half of the data points appeared multiple times and likely originated from a master’s thesis about an entirely different study. A complaint was filed with the Committee on Scientific Integrity (CWI), which on March 16 ruled that the complaint was founded. The scientific article was retracted the following month, with a reference to the integrity investigation. The university announced it would also investigate other articles published by Griep under Nijmegen’s affiliation. That investigation is still ongoing.

Second opinion

At the end of March, after the case had already become public, Griep unsuccessfully appealed the CWI ruling to the national-level scientific organ LOWI. LOWI is an independent body where accused parties in university integrity investigations can request a second opinion. Griep submitted his appeal a month after the deadline had expired; the LOWI therefore declared it inadmissible. In an anonymized report on the LOWI website, Griep stated he was “not mentally able in that period to properly keep track of his email inbox and administrative tasks.”

Meanwhile, Griep has also left his role as editor-in-chief of the journal Group and Organization Management; he is currently working as an advisor at a healthcare consultancy. The status of a special professorship he holds in Potchefstroom (South Africa) is unclear. Because this is an “internal matter,” the involved North-West University says it cannot comment. On June 1st, he still used his South African affiliation online.

The developments around Griep raise the question of who he is as a researcher and supervisor, and what led to this dramatic situation. Based on interviews and email contact with fifteen people around him, plus written sources, a picture emerges of a distinctive, ambitious psychologist who “knows how to play the game of science,” as one source puts it. But also a man with two faces who often does not work transparently. Most interviewees wish to remain anonymous (see box: Accountability).

Rising star

Until his sudden dismissal, Griep seemed a rising star in his field. He has about a hundred scientific publications, which have been cited more than 1,500 times. His h-index, a measure of productivity and therefore academic status and influence, is 22. His scientific performance is comparable to that of some professors in his department at the Behavioural Science Institute (BSI). And this while he had not even been promoted for ten years at the time of his dismissal.

He completed his doctoral research in his home country Belgium, at the Vrije Universiteit Brussel, partly under the supervision of psychologist Tim Vantilborgh, with whom he has long collaborated. After defending his dissertation, he obtained a tenure-track position at the University of Calgary. In 2019 he became an assistant professor in Nijmegen. In addition, the North-West University in Potchefstroom, South Africa, awarded him a special professorship.

His studies occasionally make the news

Much of Griep’s work concerns research into good and bad employer behavior and how this affects employee motivation and loyalty – the “psychological contract,” in academic jargon. In one of his most cited publications, written with Vantilborgh, he found, for example, that employees display counterproductive behavior – such as poorer cooperation – when their employer disappoints them.

These are sometimes engaging studies that occasionally make the news. “‘Bokito manager’ turns out to be a loss for employer: staff disengage mentally,” headlines Algemeen Dagblad last year, referring to his now-retracted scientific publication. Canadian broadcaster CBC News wrote in 2017, when Griep was working in Calgary: “Seniors who volunteer less likely to develop dementia, study suggests.” In an interview with another site, Griep explained how he was motivated by his grandfather’s experience with dementia in his final two years of life: “I felt powerless.” He also presented his findings to policymakers, including in an online webinar with the retrospectively bitter title “Understanding why saints become sinners”.

Friendly and helpful

Griep is intelligent, writes easily, and makes contact quickly, people unanimously say. A networker. “He can be very friendly and helpful,” say his former supervisor Vantilborgh and his former Nijmegen colleagues. Thanks in part to these qualities, he gained significant international experience during his PhD, working in labs in Stockholm, Toronto, Miami, and Pittsburgh. Vantilborgh: “I wasn’t surprised he was offered a position in Calgary.” His expertise in advanced statistical methods, such as structural equation modeling, also made him a sought-after collaborator.

Especially young researchers were very fond of him. “His guidance and mentorship has been invaluable to the development of myself as a student of Psychology,” one former doctoral student in Canada wrote in his dissertation acknowledgments. A Nijmegen psychologist who finished his PhD in 2023 at the BSI called Griep in his acknowledgments a major inspiration: “If you can make it in science, then there is hope for me still. Besides, you look really good”, he writes jokingly.

In Nijmegen, Griep gathered a small group of young researchers around him, among whom he was extremely popular. “A group within the group,” says a former PhD candidate who later changed supervisors after a conflict with him. The group also spent time together outside work, such as in pubs.

Self-important

But Griep also has another side, people around him say. He can be self-important and outright blunt. For example, Griep calls himself a “management magician” and wrote in 2024 in an author biography about himself: “Oh, where do I begin with the thrilling tale of Dr. Griep, the undisputed guru of management academia? Born with a spreadsheet in one hand and a strategic plan in the other, Dr. Griep emerged from the womb already equipped with a PhD in Bossing People Around.”

In a profile photo on his Radboud page, he sits on a throne dressed in a royal cloak. His sometimes striking clothing style – think brocade waistcoats or cardigans and robust square or round glasses – also contributes to an eccentric image. “It had something refreshing as well”, says one colleague. “In organizational psychology, there are also people who dress very formally.”

As a colleague, he is not equally popular with everyone. He is often away and not very involved in teaching, a former colleague says. “That is not the example I want to set as a lecturer and supervisor.” At one point, Griep goes on a “work vacation” to the United States and elsewhere; colleagues wonder whether that is fully in line with the rules.

One of the people who accompanied him is a PhD candidate from the department. He entered into a relationship with her at some point. They reported this appropriately to the department head, multiple sources confirm, as required by the university code of conduct. Griep had no formal supervisory role in her PhD trajectory, but they did publish several articles together. One of them is the retracted article in the Journal of Business Research. After the integrity investigation into this, her PhD defense was postponed at the beginning of this year because at least one dataset used for her dissertation originated from Griep.

“He regularly failed to show up for our meetings without notice”

The young woman shared an office with two female PhD candidates of whom Griep was the daily supervisor. One of them came into conflict with Griep and told Vox: “I was never very impressed by his understanding of statistics, given my own statistical expertise. I had the impression he struggled with the fact that I did not look up to him.” Their collaboration became increasingly strained, she says. “He regularly failed to show up for our meetings without notice.” Sometimes he claimed to have sent feedback that never arrived in her inbox. And the feedback that did arrive was often condescending. “This article makes no sense,” he reportedly said once. Vox saw these responses.

BSI researcher Fred Hasselman confirms the situation. The associate professor took over supervision halfway through the project because collaboration with Griep had become untenable. “I was shocked by the comments he gave on her manuscripts. His remarks on data analysis were also not fair and not applicable to the models we used.” Another colleague says he found Griep’s attitude toward PhD students “not okay.” “He is close friends with one PhD candidate, outright blunt with another, and starts a relationship with their office mate.”

Question marks

Former colleagues had long questioned Griep’s scientific integrity. During his doctoral research, everything still seemed normal, says his former supervisor Vantilborgh. “But back then, there was a lot of oversight on his data collection and analysis.”

Concerns began after his PhD, when the psychologist worked in Calgary and continued collaborating with Vantilborgh. They planned to supervise a PhD candidate together; Griep often handled the data collection.

“At one point, one of the analyses produced implausible results,” Vantilborgh explains. “When I asked him for the data to see what went wrong, he kept not providing it. Even after repeated pressure.” Griep repeatedly gave different excuses: he had not gotten around to it, or his computer had crashed.

There was also an incident involving a survey study where Griep had re-contacted participants from a previous study. This violated the agreement with the nonprofit organization that had provided access to participants, Vantilborgh says. “He said he had ‘overlooked’ that agreement.”

“It also affected me personally, because I had long had a good relationship with him”

The secrecy around his handling of data, equipment, and ethics led Vantilborgh and colleagues to lose trust. They formally ended their collaboration via email. They never received a response.

“It also affected me personally, because I had long had a good relationship with him. The thought ‘you are not who I thought you were’ went through my head.”

It is an experience shared by several Nijmegen former colleagues. “I could not reconcile those two sides of him”, one says. A formal integrity investigation was never initiated in Belgium because there was no hard evidence of fraud.

Departure from Canada

At the University of Calgary, Griep’s handling of data also allegedly led to problems. So serious that he had to leave under a non-disclosure agreement. When asked by Vox, his former department head said they could not comment. The legal department also declined to respond.

An anonymous Canadian former colleague says about Griep’s apparently concerning working practices: “It’s time that people knew so he can’t keep doing it.”

Of the scientists who published extensively with Griep, only Vantilborgh was willing to comment on the developments and on Griep as a person. Researcher Johannes Kraak (Kedge Business School, Bordeaux), co-author of the retracted article, emailed: “I prefer not to comment on personal matters and opinions.” He previously stated he no longer works with Griep since the fraud case. A joint book chapter was published last April, but that had been written earlier, Kraak said.

A researcher from the University of Toronto, with whom Griep previously secured a Canadian research grant of approximately €120,000, said she was not associated in the retracted publication: “And so have nothing to contribute.”

The two PhD candidates from his Nijmegen “group within a group” previously stated they did not want to comment beyond saying they had nothing to do with the data fraud in the retracted article, of which they are co-authors. One of them, Griep’s partner, wrote in her dissertation in laudatory and affectionate terms about him – after his summary dismissal and around the completion of the Nijmegen integrity investigation.

Griep himself has always denied all fraud allegations, but took full responsibility for the data collection and analyses in his retracted paper. The duplicate data points, Griep said to the Research Integrity Committee, were a technical error. To LOWI he emphasized: “I have never, absolutely never, fabricated or manipulated data, and I would never do so.”

In an author biography in an editorial commentary in his journal Group & Organization Management, written as the integrity investigation was nearing its conclusion, Griep wrote that his work “emphasizes open data, reproducible methods”. But he also stated that he comes from a working environment where “where methodological rigor was treated as an optional aesthetic choice,” where “data could quietly disappear when inconvenient,” and where “incentives reward productivity over correctness”. Those descriptions now appear to apply to him as well.