Hans Eysenck

Following an investigation launched in 2019, King's College London concluded that findings from publications co-authored by Eysenck and Grossarth-Maticek on personality and health were 'unsafe' and recommended that the relevant journals retract them. In October 2025, King's clarified that Eysenck's publications, including some sole-authored papers, based on the same data should also be regarded as unsafe.

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Documented

In 1952, Eysenck published a comparison of clinical outcomes and concluded that the available evidence did not support the hypothesis that psychotherapy facilitated recovery from neurotic disorders. The article became a major starting point for empirical research into psychotherapy effectiveness.

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Directly implicated

Eysenck received or oversaw substantial tobacco-industry funding for research into personality, smoking, cancer and cardiovascular disease. Historical documents and academic studies describe his role as a prominent example of industry support for alternative explanations of tobacco-related risks.

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Directly implicated

In several publications, Eysenck downplayed a direct causal interpretation of the association between smoking and cancer, assigning a major role to personality and stress factors. This position coincided with his tobacco-industry funding and was heavily criticised in light of the epidemiological evidence.

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Directly implicated

Eysenck devoted books and public appearances to parapsychology and astrology and was more open than most academic psychologists to the possibility that some claims in these fields deserved scientific examination.

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Disputed

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Directly implicated

Eysenck and Ronald Grossarth-Maticek published studies claiming exceptionally strong associations between personality types, cancer and mortality, alongside unusually large effects from preventive psychological interventions. These findings prompted repeated criticism over their implausibility and methodological problems.

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Directly implicated

During a lecture at the London School of Economics on intelligence and racial differences, protesters stormed the stage and Eysenck was physically assaulted. The episode became emblematic of the polarisation surrounding his work.

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Documented

In Race, Intelligence and Education / The IQ Argument, Eysenck defended the idea that some of the average IQ differences observed between racial groups might be hereditary and challenged the view that they were entirely attributable to environmental factors.

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Documented

Attribution

Directly implicated