Psychology (personality, smoking and disease)
Hans Eysenck: King's College London enquiry into co-authored papers, 2019 to 2025
Institute of Psychiatry, King's College London
Publications found unsafe A King's College London enquiry found the results of 26 papers he co-authored with Ronald Grossarth-Maticek unsafe in 2019, without a finding of misconduct. In October 2025 King's said publications relying on the same data should also be considered unsafe. Journals have issued retractions and expressions of concern.1,2
Papers
| Paper | Action | Date | Reason stated |
|---|---|---|---|
| 26 papers co-authored with Ronald Grossarth-Maticek 11 journals including Behaviour Research and Therapy, Psychological Reports, Personality and Individual Differences and Perceptual and Motor Skills, https://www.kcl.ac.uk/assets/news-statements/hans-eysenck-enquiry-final-may-2019.pdf1 | Found unsafe, editors notified | May 2019 | The King's committee said it considered the published results of these studies "to be unsafe" and recommended that the Principal write to the journal editors. |
| Further papers and books relying on the same data Multiple journals and publishers, https://retractionwatch.com/2025/12/03/number-of-unsafe-publications-by-psychologist-hans-eysenck-could-be-high-and-far-reaching/2 | Retractions and expressions of concern | 2020 onward | Retraction Watch reported several retractions and dozens of expressions of concern in 2020, and quoted the critic Anthony Pelosi saying the work "has led to over 20 retractions". |
Investigations
- Committee of King's College London, chaired by a person independent of King's, May 2019The committee highlighted 26 papers in 11 journals still in existence whose results it considered unsafe. It made no finding of misconduct, noted that Eysenck is deceased, and did not investigate papers by Grossarth-Maticek without an Institute of Psychiatry co-author. It said it did not have access to any data.1
- King's College London (updated statement), October 2025King's said the number of potentially relevant publications is "high and far reaching, including journal articles and books", and that any publication relying on the data from papers it had deemed unsafe should also be considered unsafe, according to Retraction Watch.2
Sources
- King's College London, King's College London enquiry into publications authored by Professor Hans Eysenck with Professor Ronald Grossarth-Maticek (May 2019)
- Retraction Watch, Number of 'unsafe' publications by psychologist Hans Eysenck could be 'high and far reaching' (3 December 2025)