Hans Eysenck is once again facing tough scrutiny.

Sybil Eysenck

In February of this year, a critical review in the Journal of Health Psychology prompted one of its editors to publish open letters calling for a formal investigation of one of the most influential and heavily cited psychologists of all time, the oft controversial Hans Eysenck.

Recently, Retraction Watch managed to lay hands on the report of such a formal investigation carried out in May by Eysenck’s long-time employer, King’s College London.

Taken together, these documents point to what Anthony Pelosi, a psychiatrist with the UK’s National Health Service in Glasgow and Honorary Professor at the University of Glasgow, calls “one of the worst scientific scandals of all time.”

Eysenck is revered as one of the greatest psychologists in history, his fame built on his work concerning intelligence and personality testing, known as psychometrics.

A 2002 paper published in the journal Review of General Psychology, ranking the 100 most eminent psychologists of the 20th century, saw him come in at number 13.



Perhaps a more telling measure is that he came third in the rankings of the “Most Frequently Cited in the Professional Psychological Journal Literature”.

Ahead of him was Jean Piaget in second place and Sigmund Freud in first, making Eysenck, at the time of his death in 1997, the most cited living psychologist.



Yet his career has, for many decades, been dogged by controversy.

He dove into the wars over the connection between IQ and race and alarmingly ended up on the academic advisory council of Mankind Quarterly, a journal commonly seen as a vehicle for dressing up racist ideology in the respectable garb of academia.

He long maintained the hereditability of IQ and personality traits and was a supporter of the work of people like Charles Murray and Richard Herrnstein, the somewhat infamous authors of The Bell Curve, a book that amongst other things makes correlations between race and IQ in the US.

This was a strange course to take for a refugee from a Nazi Germany he vehemently despised and whose own Jewish grandmother died in a concentration camp.



Eysenck also published work validating aspects of astrology to do with the correlation between personality and astrological signs and was seemingly rather partial to parapsychology and the world of psychics.

But now another aspect of his work has come in for serious scrutiny, the research he carried out with his junior collaborator Ronald Grossath-Maticek on relationships between personality and fatal illnesses such as cancer and heart disease.

Making the situation worse are the links, including financial, between Eysenck and Grossath-Maticek and the tobacco industry.



Eysenck and Grossath-Maticek together published a large number of papers that explored the idea that personality was a serious risk factor in various forms of heart disease and cancer. Famously, some of their research concluded that personality factors were six times more likely to increase the risk of lung cancer than smoking was.



This area of Eysenck and Grossath-Maticek’s research has attracted critical attention for some time, with a storm of critical publications gracing journals in the 1990s and, indeed, an entire 1991 issue of Psychological Inquiry was turned over to the topic.

Nonetheless, these issues have remained unexplored and the pair’s work still lives in the scientific literature, remaining both well-cited and influential.



Pelosi's thoroughly damning review of Eysenck and Grossath-Maticek’s research was not his first.

In the 1990s he published a similar review and had requested a formal investigation by the British Psychological Society (BPS) but was politely yet firmly shut down. Despite the suspicion, the BPS later, as Pelosi relates, reconstructed Eysenck’s lab in the Science Museum London as part of the “celebration of advances in psychology since the establishment in 1901 of the British Psychological Society”.



Eysenck’s problems seem to have begun with his association with Grossath-Maticek, a relationship that started in 1980. Grossath-Maticek’s exact affiliation is unclear, seemingly attached to Heidelberg University in Germany and later the Institute of Psychiatry at King’s College London where Eysenck worked.





However, as later investigations revealed, the first doesn’t seem clearly established and the latter is completely false.



Pelosi describes Grossath-Maticek as a doctor and social scientist, notable for the fact that he “had conducted a decade-long cohort study of more than 1300 subjects in the Yugoslav town of Crvenka. This found strong associations between suppression of aggressive feelings – which he refers to as rationality/antiemotionality – and the subsequent development of lung and other cancers.”





It wasn't the smoking that was killing you, it was your supressed rage.





Hans Eysenck of the Institute of Psychiatry, King's College Hospital, London, using a Swedish machine for measuring eye blinks.

Chris Ware/Keystone/Getty Images

Despite the fact that this theory fitted neatly with the purposes of the tobacco industry, at least one in-house scientist of the industry was deeply distrustful of both the man and his ideas, cautioning the RJ Reynolds Tobacco Company to have nothing to do with him.



This lone voice was ignored however, and the Association of Cigarette Industries of Germany began funding Grossath-Maticek. In time, even they became sceptical, realising that his data was “fudged” and that he may well be a “charlatan”.

Grossath-Maticek’s association with the older and revered Eysenck was fortuitous on this front, as the latter managed to secure further funding from the tobacco companies to continue pursuing the research on the relationship between personality and ill health.

The research moved, according to Pelosi, away from Grossath-Maticek’s rationality/antiemotionality measures to a typology of personality comprising four distinct personality types, clearly influenced by Eysenck: a cancer-prone personality, a heart disease-prone personality, a mixture personality and a healthy personality.

“This collaboration,” writes Pelosi, “led to what must be the most astonishing series of findings ever to be published in the scientific literature.”

One study using data from Grossath-Maticek’s Yugoslav cohort and from more recent research conducted on patients from Heidelberg, indicated “38.5% of the cancer-prone subjects died of cancer compared with only 0.3% of those with the healthy personality,” a result that accords the cancer-prone personality type a relative risk that Pelosi describes as “perhaps the highest ever identified in non-infectious disease epidemiology.”

Another study on the efficacy of psychotherapy in preventing cancer showed 100% of treated subjects did not die of cancer in the following 13 years, compared to 32% of an untreated control group.

Perhaps most alarming results were connected to Eysenck and Grossath-Maticek’s notion of ‘bibliotherapy’ which consisted of, as Eysenck put it, “a written pamphlet outlining the principles of behaviour therapy as applied to better, more autonomous living, and avoidance of stress.”

This was coupled with five hours of discussion, aimed both at reorienting a patient’s personality away from the cancer-prone and toward a healthier disposition. The results of this study, according to Pelosi, were that “128 of the 600 (21%) controls died of cancer over 13 years compared with 27 of 600 (4.5%) treated subjects.

"Such results are otherwise unheard of in the entire history of medical science.” There were similarly spectacular results concerning various forms of heart disease too.

These decidedly improbable findings led to a blizzard of critical scrutiny through the 90s: Eysenck and Grossath-Maticek’s work was attacked for its methodology, statistical treatment and ethics.

One researcher who attempted a sympathetic review of the work, in cooperation with the pair, found, says Pelosi, “unequivocal evidence of manipulation of data sheets,” from the Heidelberg cohort, as well as numerous patient questionnaires with identical responses.

An attempt at replicating some of their results concerning heart disease provided cold comfort, indicating that the personality type association with coronary illness was non-existent for all but one of the types.

A slightly modified replication of Eysenck and Grossath-Maticek’s research on personality and cancer faired no better, with the author, Manfred Amelang, writing “I know of no other area of research in which the change from an interview to a carefully constructed questionnaire measuring the same construct leads to a change from near-perfect prediction to near-zero prediction.” Recommended Animals, science, behaviour and ethics Society

As David Marks, the editor of the Journal of Health Psychology put it, “There is absolutely no scientific evidence that any of these statements are true, and Eysenck is proved by his own words to be guilty of some of the most egregious and harmful falsehoods made by any psychologist ever.”

Eysenck’s response to critics at the time was breezy, painting his protégé as a visionary persecuted by pedants:



"Grossarth-Maticek is the wide-ranging creative scientist, working on a large scale, impatient of detail, concerned with the wider issues, the broad strokes, the major breakthrough.

"Irritated by doubts and criticisms, conscious of the enormous social and scientific importance of his discoveries, convinced (rightly) that his work and theories are streets ahead of what his critics have to offer, he obviously does not suffer fools gladly and he may hit out at them in a rather exaggerated way."

“This battle,” Eysenck noted, “is age-old, and few creative scientists escape it.”

David Marks sees this as disingenuous, covering up a far more damaging situation:

"To his eternal shame, the attempts by Hans Eysenck to discredit the well-established causal links between tobacco smoking and cancer while in receipt of large sums from the tobacco industry is one of the most shameful deceits committed by any scientist in the 20th century."

And so things stood until this year. No formal investigations were undertaken despite an ever-increasing body of work casting a deep shadow across the reputation of one of Britain’s most famous psychologists. Pelosi’s assessment of this inaction was incredibly damning:

"In my opinion, it is one of the worst scandals in the history of science, not least because the Heidelberg results have sat in the peer-reviewed literature for nearly three decades while dreadful and detailed allegations have remained uninvestigated."

Why was there such inertia? It’s hard to understand given the fact that Eysenck and Grossarth-Maticek’s work is still widely cited and appears in many textbooks at varying levels.

One author noted in 2016 “several major conceptual and methodological paradigms for the study of the impact of psychological, genetic, and lifestyle factors on physical health”.

Particularly concerning is that their work on personality, cancer and smoking still receives rave reviews from academics and scientists. Worse still, it seems to have influenced the actual clinical research of cancer treatment.

The editorial by Marks that accompanying Pelosi’s review in February endorsed Pelosi’s findings and included open letters to both Kings College London and the British Psychological Society, pleading for a formal investigation.

“A full and thorough investigation,” he wrote, “would be good for science, for the research integrity of your esteemed institution and for the welfare of patients and the general public.” Staggeringly, he called for “the retraction or correction of 61 publications including more than 40 journal articles, 10 book chapters and 2 books, each in 3 editions.”



According to Retraction Watch, Pelosi’s forensic review and Marks’ eloquent plea have borne fruit, though perhaps not quite as fully as hoped.

Kings College London undertook a formal internal investigation of publications by Eysenck with Grossarth-Maticek, limiting itself to publications by employees of the then Institute of Psychiatry, which includes Eysenck but not Grossarth-Maticek, who, despite his claiming the affiliation repeatedly, was never actually an employee of the Institute.



Their conclusion, published in May, is stark:

“We have come to the conclusion that we consider the published results of studies that included the results of the analyses of data collected as part of the intervention or observational studies to be unsafe and that the editors of the journals should be informed of our decision. We have highlighted 26 papers … which were published in 11 journals which are still in existence.”

Exactly what ‘unsafe’ means in the context is unclear, but it is obvious that this does not bode well for Eysenck’s legacy, despite Kings College London only flagging 26 articles for possible retraction or correction, rather than the 61 noted by Marks. As James Heathers, an investigator of scientific misconduct, writes for Retraction Watch:

“If these papers were retracted, it would vault Eysenck – more than a decade after his death – onto the Retraction Watch leaderboard, tied for 22nd. If the full body of 61 documents was retracted, Eysenck would eclipse Diederik Stapel (58) as the most retracted psychologist in history, a scarcely believable legacy for someone who was at one time the most cited psychologist on the planet.”

Perhaps now we will see the 11 journals that have been contacted by Kings College London take some action to undo the dangerous legacy left by Eysenck and Grossarth-Maticek. If the editors of these journals have the strength to act, then perhaps other publishers, publications and institutions will be emboldened to tackle this stain on British psychology as well.

While there is every reason to correct the scientific record for the sake of the integrity of science itself, there are real and pressing reasons beyond.

As Pelosi powerfully writes, “these widely cited studies have had direct and indirect influences on some people’s smoking and lifestyle choices. This means that for an unknown and unknowable number of individual men and women, this programme of research has been a contributory factor in premature illness and death.”