HANS EYSENCK

Hans Jürgen Eysenck was a psychologist born in Germany, who spent his professional career in Great Britain. * He is best remembered for his work on intelligence and personality, though he worked in a wide range of areas. * Eysenck was Professor of Psychology at the Institute of Psychiatry, King's College, London (a constituent college of the federal University of London), from 1955 to 1983. * He was a major contributor to the modern scientific theory of personality and a brilliant teacher who helped found treatment for mental illnesses.
Born: March 4, 1916, Berlin, Germany
Died: September 4, 1997, London, United Kingdom died because of a brain tumour in a London hospice
Education: University College London

Eysenck's theory of personality was created in 1947.Eysenck's theory is based on physiology and genetics.Eysenck stated that personality differences is someone growing out of their genetic inheritance. Eysenck fought hard against the trend that personality involves biology and the environment. He figured out that all human traits can be broken down into two different categories-
Neuroticism and Introversion-Extroversion. Neuroticism ranges from normal and fairly calm to people that are very nervous. This doesn't mean that someone is neurotic but people who fall into this category are more likely to develop neurotic disorders later in life.
Extraversion-introversion, this term means shy, or quiet people versus outgoing or loud people. Extroversion types of personalities need a lot of stimulation and often express emotions. They are usually relaxed and very confident. Introversion personality types need little external stimulation. They focus more on their inner feelings and bottle them up. They do explode if they are pushed too far. After a lot of research Eysenck realized that his theory didn't reach all people. He started to study in mental institutions and he labeled a new category, he called it Psychoticism. People who fell into this category were not necessarily psychotic or you will be, only that you show some of the same traits that people who are psychotic have.
Eysenck's test of personality is a series of questions that you rate yourself on. All of the questions have to do with the four categories that Eysenck discovered. At the end of the test Eysenck would read all the data and determine which traits fit the best.
He called these categories Supertraits (See figure below). According to his theory, everyone exhibits specific responses to both internal and external stimuli. These specific responses will vary according to the intensity of the stimuli, the situation, state of mind, and many other factors. At some point, however, we will begin to see trends in how we respond. A person who is very concerned with how other people view her, might shy away from a stranger in most specific situations. When this behavior becomes the normal way to respond to new people, the response then becomes a habit.
Suppose now that she also avoids public settings where a large number of people gather, or possibly limits her social activity to only a few trusted friends. When all of these habitual responses are combined, the become part of a larger group known as a trait. In this case, the trait may be called shyness or perhaps even social phobia.
This trait, Social phobia, is a component of one of the three supertraits, introversion-extroversion. If we see that she also prefers soft music over loud music, intellectual pursuits over than team sports, or other similar solo activities, we could then classify her as an introvert.
When we look at an individuals specific responses, combine them into habitual responses, further develop a set of specific traits and then determine where they fall on the two supertraits, we would notice that the vast differences in personality prohibit us from such a simple theory. Because of this, Eysenck argued that there were varying degrees of each of the two supertraits and most of us fall somewhere on the spectrum between Stable versus Unstable (neurotic) and Introverted versus Extroverted.
The figure below describes that diagram. The person who is high on extroversion and high on stability may fall in the lower right quadrant of the circle. Those who are less stable and more introverted would fall somewhere in the upper left. According to this diagram, each of us will ultimately fall somewhere on the circle based on a sum of our responses and traits.

Other Contribution of Eysenck
The Psychology of Politics
In this book, Eysenck suggests that political behavior may be analyzed in terms of two independent dimensions: the traditional left-right distinction, and how 'tenderminded' or 'toughminded' a person is. Eysenck suggests that the latter is a result of a person's introversion or extroversion respectively.
Colleagues criticized the research that formed the basis of this book, on a number of grounds, including the following.
Eysenck claims that his findings can be applied to the British middle class as a whole, but the people in his sample were far younger and better educated than the British middle class as a whole.
Supporters of different parties were recruited in different ways: Communists were recruited through party branches, fascists in an unspecified manner, and supporters of other parties by giving copies of the questionnaire to his students and telling them to apply it to friends and acquaintances.
Scores were obtained by applying the same weight to groups of different sizes. For example the responses of 250 middle-class supporters of the Liberal Party were given the same weight as those of 27 working-class Liberals.
Scores were rounded without explanation, in directions that supported Eysenck's theories.
Genetics of personality
In 1951, Eysenck's first empirical study into the genetics of personality was published. It was an investigation carried out with his student and associate Donald Prell, from 1948 to 1951, in which identical (monozygotic) and fraternal (dizygotic) twins, ages 11 and 12, were tested for neuroticism. It is described in detail in an article published in the Journal of Mental Science. Eysenck and Prell concluded: "that the factor of neuroticism is not a statistical artifact, but constitutes a biological unit which is inherited as a whole....neurotic predisposition is to a large extent hereditarily determined."

Model of personality
The two personality dimensions, extraversion and neuroticism, 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 two-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 Hippocrates. * 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
Eysenck Personality Wheel:

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, 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.[citation needed] 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". Similarly, Eysenck proposed that location within the neuroticism dimension was determined by individual differences in the limbic system. 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 his or her arousal to a more favourable level (as predicted by the Yerkes-Dodson Law) by increased activity, social engagement and other stimulation-seeking behaviors.

Factor Analysis
A statistical technique used to determine the number of components in a set of data. These components are then named according to their characteristics allowing a researcher to break down information into statistical groups.

Psychometric scales:
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.

In psychology, Eysenck Personality Questionnaire (EPQ) is a questionnaire to assess the personality traits of a person. It was devised by the psychologists Hans Jürgen Eysenck and his wife Sybil B. G. Eysenck.
Hans Eysenck's theory is based primarily on physiology and genetics. Although he was a behaviorist who considered learned habits of great importance, he considers personality differences as growing out of our genetic inheritance. He is, therefore, primarily interested in what is usually called temperament.
Temperament is that aspect of our personalities that is genetically based, inborn, there from birth or even before. That does not mean that a temperament theory says we don't also have aspects of our personality that are learned, it's just that Eysenck focused on "nature," and left "nurture" to other theorists.