Univers found a remarkable message on the expert page of Joris Lammers, associate professor at Tilburg University.
While most researchers, at the request of Tilburg University, do not comment on the matter Diederik Stapel, Lammers wrote on his expert/expertise page of Tilburg University:
“There are serious doubts regarding the reliability of the data of one of my co-authors, Stapel. I want to stress that I have gathered all data reported here myself or have personally overseen its collection (for example, by students). There is 1 article of which I am not sure. That article is not mentioned on this website”.
Lammers does not say which article is possibly fraudulent. On his expert page he only mentions the articles that are definitely not infected by fraudulent data of Diederik Stapel. After comparing this list with a list of publications by Diederik Stapel, one article, ‘Power and behavorial approach orientation in existing power relations and the mediating effect of income’, co-authored with Lammers and J. Stoker (published in the European Journal of Social Psychology), is missing. No one at the university could confirm whether this is one of the articles the commission Levelt is investigating.
When asked why he has put such a remarkable text on his webwijs page, Lammers replied that he did so to inform those who know that he has worked with Stapel in advance, before they start asking questions.
Update 13 October: Lammers has now removed the text from his webwijspage.