Diederik Stapel voluntarily renounced his doctorate title from the University of Amsterdam (UvA) on 9 November 2011. The certificate he received in 1997 after obtaining his PhD is now back in possession of the University.
Stapel has stated in writing that he wishes to renounce his doctorate title, as he believes that his behaviour in recent years is in contravention with the duties connected with a doctorate degree. Stapel graduated in 1997 from the UvA. He worked there from 1993 to 1999, before working in Groningen and Tilburg. On 31 October 31 the Levelt Commission, which examined the academic integrity of Stapel’s work, advised the UvA to investigate whether the PhD of Mr Stapel could be rescinded.