Hans Eysenck

{{PersonPsy}

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

Hans Eysenck was born in Germany, but moved to England as a young man in the 1930s because of his opposition to the Nazi party. Eysenck was the founding editor of the journal Personality and Individual Differences, and authored over 50 books and over 900 academic articles. He aroused intense debate with his controversial dealing with variation in IQ among racial groups (see race and intelligence).

Life and work
Eysenck was professor of psychology at the Institute of Psychiatry (IoP) 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 behavioural treatments for mental disorders.

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


 * A paper in the 1950s 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 (1978).
 * Astrology - Science or Superstition? (1982)
 * Smoking, Personality and Stress (1991)

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

By far the most acrimonious of the debates has been that over the role of genetics in IQ differences (See Genetics vs. environment), which led to Eysenck famously being punched on the nose during a talk at the London School of Economics.

Eysenck's attitude is summarised in his autobiography Rebel with a Cause (Transaction Publishers (1997), ISBN 1-56000-938-1): "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."

Eysenck's model of personality (P-E-N)
Eysenck was one of the first psychologists to study personality with the method of 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, and Eysenck referred to it as Neuroticism. The second factor was the tendency enjoy positive events, especially social events, and Eysenck named it Extraversion. The 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 behaviour. An analogy can be made to how latitude and longitude describe a point on the face of the earth. Also, 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 (e.g., Eysenck & Eysenck, 1969; 1976), who is the current editor of Personality and Individual Differences.

The major strength of Eysenck's model was to provide detailed theory of the causes of personality. For example, Eysenck proposed that extraversion 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 extraverts, the putative effect this has on behaviour is such that the introvert seeks lower levels of stimulation. Conversely, the extravert 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 behaviours.

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 (see big five personality traits). 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 calles 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).

Another important model of personality is that of Jeffrey Gray, a former student of his.

Eysenck has always insisted that his use of the term "extraversion" does not correspond to the usage adopted by Carl Jung, and has also challenged the popular belief that Jung coined the term.

Psychometric scales relevant to Eysenck's theory
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.

Eysenck's later work
Eysenck made early contributions to fields such as personality by express and explicit commitment to a very rigorous adherence to scientific methodology, as Eysenck believed that scientific methodology was required for progress in personality psychology. He used, for example, factor analysis, a rigorous statistical method, to support his personality model. His early work showed Eysenck to be an especially strong critic of psychoanalysis as a form of therapy, preferring behaviour 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.