Hans Eysenck

From New World Encyclopedia

Hans Jürgen Eysenck (March 4, 1916 - September 4, 1997) was an eminent psychologist, most remembered for his work on intelligence and personality, though he worked in a wide range of areas. He was a prolific writer, producing 60 books and 1,000 academic articles. A brilliant teacher and thinker, his work was frequently controversial, involving him in numerous public debates. His work on individual differences, while providing much needed theoretical and methodological advances, also involved him in the most heated arguments due to his support for the position that racial differences in intelligence scores had a genetic basis. Never afraid of controversy, and confident in his ability to apply the Scientific Method to issues of importance, Eysenck defended his beliefs by reminding the world that opposition to Nazism in his native country of Germany was unpopular but right.

Hans Eysenck sent shock waves through the academic world and public forums alike, promoting himself as a self-made "rebel with a cause." He embodied the genius of a true intellectual who strove to do work that was of wide relevance and humane import. In the end, however, his model of human intelligence consisted of elements such as processing speed and error-checking ability, that, while they may well be biologically determined, do not reflect the essential core of what is uniquely human—the ability to love and thus to transcend external, physical attributes.


Hans Jürgen Eysenck was born in Germany, March 4, 1916, to Eduard Anton Eysenck, an actor, and Ruth Eysenck (née Werner, stage name Helga Molander). The marriage soon collapsed and Ruth re-married a film producer and writer, Max Glass. As the Nazi influence grew, Ruth and Max (who were both Jewish) were forced to leave Germany for France. Hans was entrusted to Ruth's mother (Frau Werner, once an opera singer), who continued to raise him in his hometown, Berlin. They lived in fairly comfortable circumstances, surrounded by literary and cultural influences. Hans refused to join the Hitler Youth and spent time studying in England.

Hans immigrated to England in 1934, and in 1938, he received his B.A. from the University of London. His grandmother, Frau Werner, later died in a concentration camp. After the fall of France, Hans' mother, Ruth, was also interned. Her husband exhausted his fortune to bribe the Nazis for her release. Finally, she joined him in South America, a new fortune was built, and the couple returned to Paris.

In 1938, Eysenck married a graduate student, Margaret D. Davies (with whom he published one article, on aging). Eysenck's son from this marriage, Michael, became a professor of psychology at London's Royal Holloway and Bedford New College. His Handbook of Cognitive Psychology was soon a best-seller, and his book with his father, Personality and Individual Differences, was favorably reviewed in Nature—a rare distinction for psychological authors.

Hans desired to join the Royal Air Force during the Second World War but was barred due to his German origin; so his contribution to the war effort was as a fire-watcher. He obtained his Ph.D. in 1940, and soon thereafter founded the department of psychology in the newly created Institute of Psychiatry at the University of London. He was later made professor of psychology there in 1955.

In 1950, Eysenck had a second marriage to Sybil Bianca Guiletta (daughter of violinist Max Rostal OBE), with whom he had three sons and one daughter.

Eysenck was the founding editor of the journal, Personality and Individual Differences, and authored 60 books and 1,000 academic articles. He aroused intense debate with his controversial dealing with variation in intelligence among racial groups.

At the time of his death on September 4, 1997, Eysenck was the living psychologist most frequently cited in science journals (Haggbloom et al., 2002).


Hans Eysenck was professor of psychology at the Institute of Psychiatry in London from 1955 to 1983. He was a major contributor to the modern scientific theory of personality and a brilliant teacher who also played a crucial role in the establishment of behavioral treatments for mental disorders.

He was a prolific writer, and his thoughts went so fast that ordinary writing speed was not able to match. He used a portable Dictaphone to write his books and passed it to his secretary to transcribe the tape into words afterwards. A former student and colleague of his, Arthur Jensen, praised his ability to give outstanding extemporaneous lectures. One of his lectures on the history of personality research appeared several months later in the British Journal of Psychology. Jensen remarked that even though the lecture was given spontaneously, it was so precise that the article was written word for word just as he had remembered it from the lecture.

However, Eysenck's work was often controversial. Publications in which Eysenck's views aroused controversy include (chronologically):

  • A paper in the 1950s, The Effects of Psychotherapy: An Evaluation, concluding that available data "fail to support the hypothesis that psychotherapy facilitates recovery from neurotic disorder."
  • A chapter in Uses and Abuses of Psychology (1953) entitled, "What is wrong with psychoanalysis."
  • Race, Intelligence and Education (1971) (The IQ Argument in the U.S.)
  • Sex, Violence and the Media (1979)
  • Astrology—Science or Superstition? (1982)
  • Smoking, Personality, and Stress (1991)

Eysenck also earned criticism for accepting funding from the Pioneer Fund, a controversial eugenics organization.

By far the most acrimonious of the debates was over the role of genetics in IQ differences, which led to Eysenck famously being punched on the nose during a talk at the London School of Economics. In 1969, Eysenck’s student, Arthur Jensen, published a controversial paper asserting that racial differences in intelligence test scores might have genetic origins (Jensen, 1969). Eysenck received much criticism for defending Jensen in the ensuing controversy. Later, Eysenck published his own evidence that biological processes might be a factor in racial differences in intelligence (1971). However, when he wrote his 1990 autobiography, he had moderated his views to give more weight to environmental influences (Mclaughlin, 2000).

Eysenck's attitude to his work and the controversies generated by it, is summarized in his autobiography, Rebel with a Cause (1997):

I always felt that a scientist owes the world only one thing, and that is the truth as he sees it. If the truth contradicts deeply held beliefs, that is too bad. Tact and diplomacy are fine in international relations, in politics, perhaps even in business; in science only one thing matters, and that is the facts.

He also said of himself:

From the days of opposition to Nazism in my early youth, through my stand against Freudianism and projective techniques, to my advocacy of behavior therapy and genetic studies, to more recent issues, I have usually been against the establishment and in favor of the rebels, [But] I prefer to think that on these issues the majority were wrong, and I was right.

In 1994, Eysenck was one of 52 signatories on "Mainstream Science on Intelligence," an editorial written by Linda Gottfredson and published in the Wall Street Journal, which defended the findings on race and intelligence in the controversial publication by Richard Herrnstein and Charles Murray, The Bell Curve.

Eysenck made early contributions to fields such as personality by his express and explicit commitment to a very rigorous adherence to scientific methodology, believing that scientific methodology was required for progress in personality psychology. His early work showed him to be an especially strong critic of psychoanalysis as a form of therapy, preferring behavior therapy. Despite this strongly scientific interest, Eysenck was not shy, in later work, of giving attention to parapsychology and astrology. Indeed, he believed that empirical evidence supported the existence of paranormal abilities.

Eysenck was also primarily a research psychologist, and his methods involved the use of the statistical technique called factor analysis. This technique allowed him to extract a number of “dimensions” from large amounts of data, whether they be measures of intelligence or personality.

Eysenck's theory is based primarily on physiology and genetics. A behaviorist, Eysenck regarded learned habits of great importance and that experience was the method by which each individual developed their biological potential. However, he considered personality differences as growing out of genetic inheritance. He was, therefore, primarily interested in what is usually called temperament.

Measurement of intelligence

Eysenck was a proponent of the theory of human intelligence proposed by Donald Hebb and elaborated by Philip Vernon. Hebb called the biological substrate of human cognitive ability “Intelligence A.” When Intelligence A interacts with environmental influences, "Intelligence B" is generated. Hebb regarded Intelligence B as essentially immeasurable due to the large number of confounding variables, and Intelligence A not as a concrete “thing” that can be measured. Eysenck believed that culturally-bounded tests and tests of educational attainment were likely to capture the environmentally influenced Intelligence B, whereas physiological measures such as positron emission tomography (PET) and electroencephalography (EEG) held more potential as possible tools for capturing the genetically based Intelligence A (Jensen, 1994).

Philip Vernon had elaborated Hebb's view to include "Intelligence C," which is what manifests on tests of cognitive ability. Vernon also believed that different tests, however, are imperfect and vary to the degree that they reflect Intelligence A or B. Although he acknowledged the pivotal role of environmental factors, Vernon’s research led him to conclude that approximately 60 percent of the variance in human intellectual ability is attributable to genetic contributions. He extended this argument to implicate genes in the observed racial differences in intelligence test scores. This controversial line of research was pursued by Eysenck and his student Arthur Jensen, culminating in 1971, with the publication of Race, Intelligence, and Education, for which Eysenck was physically assaulted by "progressive intellectuals" at a public talk.

Eysenck also carried support for the "general intelligence" factor ("g") proposed by Cyril Burt. One of Eysenck's most influential papers, linking general intelligence to mental speed, "Intellectual Assessment: A Theoretical and Experimental Approach," published in 1967, described his efforts to develop accurate measurement of the elusive concept of human intelligence. Always a proponent of advanced statistical methods to evaluate the complexities of the data required to encapsulate the essence of the human mind, Eysenck concluded:

If we can derive a model of the intellect, therefore, from the existing literature, it may be suggested that a combination of Spearman’s g, Thurstone’s primary abilities (grouped under mental processes and test material), and the break-down of the IQ into speed, persistence and error-checking, may be the best available at the moment (Eysenck, 1979, p. 193).

Eysenck's model of personality (P-E-N)

Eysenck was one of the first psychologists to study personality using factor analysis, a statistical technique introduced by Charles Spearman. Eysenck's results suggested two main personality factors.

The first factor was the tendency to experience negative emotions, which Eysenck referred to as Neuroticism. The Neuroticism (N) trait is measured on a bipolar scale anchored at the high end by emotional instability and spontaneity, and by reflection and deliberateness at the low end. Individuals high on the N trait are susceptible to anxiety-based problems. The second factor was the tendency to enjoy positive events, especially social events, which Eysenck named Extraversion. The Extraversion (also spelled Extroversion) (E) trait is measured on a bipolar scale that is anchored at the high end by sociability and stimulation-seeking, and at the low end by social reticence and stimulation avoidance. These two personality dimensions were described in his 1947 book Dimensions of Personality. It is common practice in personality psychology to refer to the dimensions by the first letters, E and N.

E and N provided a 2-dimensional space to describe individual differences in behavior. An analogy can be made to how latitude and longitude describe a point on the face of the earth. Eysenck noted how these two dimensions were similar to the four personality types first proposed by the Greek physician Galen.

  • High N and High E = Choleric type
  • High N and Low E = Melancholic type
  • Low N and High E = Sanguine type
  • Low N and Low E = Phlegmatic type

The third dimension, Psychoticism, was added to the model in the late 1970s, based upon collaborations between Eysenck and his wife, Sybil B.G. Eysenck (Eysenck & Eysenck, 1969; 1976). The Psychoticism (P) trait is a bipolar scale anchored at the high end by aggressiveness and divergent thinking, and at the low end by empathy and caution. One common misconception about the P scale is that it is diagnostic for psychosis. The EPQ is not a diagnostic instrument. While appropriateness of the label “Psychoticism” for the trait has been debated, it has nevertheless been retained. Eysenck's measurement instruments also contain a Lie (L) scale that has been shown to function as an index of socialization or social conformity. The L scale is a measure of the degree to which one is disposed to give socially expected responses to certain types of questions.

Eysenck's studies of antisocial behavior (ASB) in children revealed that individuals at risk for developing ASB had above average P scale scores. In addition, individuals who were also high on the E and N scales and below average on the L scale were at the greatest risk. Eysenck proponents have suggested implementing preventive programs targeting children at-risk for developing ASB based on temperamental predispositions.

The major strength of Eysenck's model was to provide data supporting a clear theoretical explanation of personality differences. For example, Eysenck proposed that extroversion was caused by variability in cortical arousal; "introverts are characterized by higher levels of activity than extraverts and so are chronically more cortically aroused than extraverts" (Eysenck & Eysenck, 1985). While it seems counterintuitive to suppose that introverts are more aroused than extroverts, the putative effect this has on behavior is such that the introvert seeks lower levels of stimulation. Conversely, the extrovert seeks to heighten their arousal to a more optimal level (as predicted by the Yerkes-Dodson Law) by increased activity, social engagement, and other stimulation-seeking behaviors.

Comparison with other theories

The major alternative to Eysenck's three factor model of personality is a model that makes use of five broad traits, often called the Big Five model. The traits in the Big Five are as follows:

  1. Extraversion
  2. Neuroticism
  3. Conscientiousness
  4. Agreeableness
  5. Openness to experience

Extraversion and Neuroticism in the Big Five are similar to Eysenck's traits of the same name. However, what Eysenck called the trait of Psychoticism corresponds to two traits in the Big Five model: Conscientiousness and Agreeableness. Eysenck's personality system did not address Openness to experience. He argued that his approach was a better description of personality (Eysenck, 1992a; 1992b).

Aside from Jung's basic premise of an association between the dichotomy of introversion-extroversion and the type of neurosis they were liable to develop, Eysenck accepted none of Jung's formulation. In fact, Eysenck went to great lengths to point out that the concepts of introversion-extroversion were not originated by Jung, but by many others, going back as far as Galen and Hippocrates.

Eysenck's theory of personality is closely linked with the scales that he and his co-workers developed. These include the Maudsley Medical Questionnaire, Eysenck Personality Inventory (EPI), Eysenck Personality Questionnaire (EPQ), and Sensation Seeking Scale (developed in conjunction with Marvin Zuckerman). The Eysenck Personality Profiler (EPP) breaks down different facets of each trait considered in the model. There has been some debate about whether these facets should include impulsivity as a facet of Extraversion, as Eysenck declared in his early work, or Psychoticism. Eysenck declared for the latter, in later work.


Hans Eysenck was considered the leader of the “London School” of psychology, which applied Darwin’s theory of evolution to the study of individual differences. His landmark works The Biological Basis of Personality (1967) and Personality Structure and Measurement (1968) established Eysenck as a towering figure in British psychology. In 1993, he was honored with the U.S. Presidential Citation for Scientific Contribution; in 1994, he received the William James Fellow Award (American Psychological Society); and in 1996, bestowed with the Centennial Award for distinguished contributions to clinical Psychology (American Psychological Society).

His lifetime goal, as described in his autobiography, Rebel with a Cause (1997), was to make twentieth century human psychology a true science. At the time of his death at age 81, he had published 60 books and 1000 articles and was the most cited person in the Social Sciences Citation Index.

Selected Publications

  • [1947] 1997 Dimensions of Personality. Transaction Publishers. ISBN 978-1560009856
  • 1952 The Scientific Study of Personality.
  • 1952 The Structure of Human Personality. And later editions
  • 1953 Uses and Abuses of Psychology.
  • 1954 The Psychology of Politics.
  • 1955 Psychology and the Foundations of Psychiatry.
  • 1956 Sense and Nonsense in Psychology.
  • 1957 Perceptual Processes and Mental Illnesses. With G. Granger and J. C. Brengelmann
  • 1957 The Dynamics of Anxiety and Hysteria.
  • 1959 Manual of the Maudsley Personality Inventory.
  • 1960 Handbook of Abnormal Psychology. Editor, later editions
  • 1960 Experiments in Personality. Two volumes, editor
  • 1960 Behaviour Therapy and Neuroses. Editor
  • 1962 Know Your Own I.Q..
  • 1963 Experiments with Drugs. Editor
  • 1964 Experiments in Motivation. Editor
  • 1964 Crime and Personality. And later editions
  • 1964 Manual of the Eysenck Personality Inventory. With S. B. G. Eysenck
  • 1965 Fact and Fiction in Psychology.
  • 1965 Smoking, Health and Personality.
  • 1965 The Causes and Cures of Neuroses. With S. Rachman
  • 1966 Check Your Own I.Q..
  • 1966 The Effects of Psychotherapy.
  • [1967] 2006. The Biological Basis of Personality. With S. B. G. Eysenck. Transaction Publishers. ISBN 978-1412805544
  • 1968 Personality Structure and Measurement. With S.B.G. Eysenck. ISBN 0912736089
  • 1969 Personality Structure and Measurement ISBN 0710060483
  • 1971 Race, Intelligence and Education in U.S. as The IQ Argument. ISBN 0912050160
  • 1971 Readings in Extraversion/Introversion. Three volumes
  • 1972 Lexicon de Psychologie. Three volumes. with W. Arnold and R. Meili.
  • 1972 Psychology is about People.
  • 1973 Eysenck on Extraversion. Editor
  • 1973 The Inequality of Man.
  • 1973 The Experimental Study of Freudian theories. With G. D. Wilson
  • 1973 The Measurement of Intelligence. Editor
  • 1974 Case Histories in Behaviour Therapy. Editor
  • 1975 Know Your Own Personality. with G. D. Wilson
  • 1975 Manual of the Eysenck Personality Questionnaire. With S. B. G. Eysenck
  • 1976 A Textbook of Human Psychology. With G. D. Wilson
  • 1976 Sex and Personality.
  • 1976 The Measurement of Personality Editor
  • 1976 Psychoticism as a Dimension of Personality. With S. B. G. Eysenck ISBN 0340209194
  • 1977 Reminiscence, Motivation and Personality With C. D. Frith
  • 1977 You and Neurosis
  • 1997 Die Zukunft der Psychologie
  • 1978 The Psychological Basis of Ideology. Editor, with G. D. Wilson
  • 1979 Sex Violence and the Media. ISBN 0060906847
  • 1979 The Structure and Measurement of Intelligence.
  • 1979 The Psychology of Sex. With G. D. Wilson.
  • 1980 The Causes and Effects of Smoking.
  • 1981 A Model for Personality. Editor.
  • 1981 Mindwatching. With M. W. Eysenck.
  • 1981 The Battle for the Mind. With L. J. Kamin, in U.S. as The Intelligence Controversy.
  • 1982Explaining the Unexplained. With Carl Sargent
  • 1982 Astrology – Science or Superstition? With D. Nias ISBN 0312058063
  • 1982 Personality, Genetics and Behaviour.
  • 1982 A Model for Intelligence. Editor
  • 1983 …'I Do'. Your Happy Guide to Marriage. With B. N. Kelly
  • 1983 Know Your Own Psi-Q. With Carl Sargent.
  • 1985 Decline and Fall of the Freudian Empire.
  • 1985 Personality and Individual Differences: A Natural Science Approach. With M. W. Eysenck
  • 1987 Rauchen und Gesundheit.
  • 1988 Theoretical Foundations of Behaviour Therapy. Editor, with I. Martin
  • 1989 Genes, Culture and Personality: An Empirical Approach. With L. Eaves and N. Martin
  • 1989 Suggestion and Suggestibility. Editor, with V. A. Gheorghiu, P. Netter, and R. Rosenthal
  • 1989 The Causes and Cures of Criminality. With G. H. Gudjonsson
  • [1990] 1997 Rebel With a Cause. ISBN 1560009381
  • 1991 Smoking, Personality and Stress: Psychosocial Factors in the Prevention of Cancer and Coronary Heart Disease. ISBN 0387974938
  • 1995 Test Your IQ. With Darrin Evans. Penguin. ISBN 978-0140249620

ISBN links support NWE through referral fees

  • Center, David B. and Dawn E. Kemp. 2002. "Antisocial Behaviour in Children and Eysenck's Theory of Personality: An evaluation." In International Journal of Disability, Development & Education. (Vol. 49). 4 p353-366.
  • Eysenck, H. J. 1992. "A reply to Costa and McCrae. P or A and C—the role of theory." In Personality and Individual Differences. 13, 867-868. ISBN 0306418444
  • Eysenck, H. J. 1992. "Four ways five factors are not basic." In Personality and Individual Differences. 13, 667-673. Springer Publisher. ISBN 0306418444
  • Eysenck, H. J. 1967. "Intellectual assessment: a theoretical and experimental approach." In British Journal of Educational Psychology.
  • Haggbloom, S. J. 2002. "The 100 most eminent psychologists of the 20th century." In Review of General Psychology. 6, 139-152.
  • Jensen, A. R. 1994. "Eysenck, Hans J. (1916-)" In Encyclopedia of Human Intelligence. New York: Macmillan. ISBN 0028974077
  • Mcloughlin, C. S. 2002. "Jurgen Hans Eysenck." In Encyclopedia of psychology (Vol.3). pp. 310-311. Oxford: Oxford University Press. ISBN 978-1557981875

External links

All links retrieved June 25, 2024.


New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

The history of this article since it was imported to New World Encyclopedia:

Note: Some restrictions may apply to use of individual images which are separately licensed.