Hans Eysenck proposed a hierarchical model of personality that is strongly rooted in biology. The major dimensions in Eysenck's model are extraversion, neuroticism, and psychoticism. Eysenck believed these personality traits are caused by genetic predispositions and environmental factors. He also believed personality traits represent predispositions that can be modified through learning and conditioning techniques. Eysenck used factor analysis and other research methods to study personality dimensions and their biological underpinnings.

1. EYSENCK’S
HIERARCHICAL MODEL
MANAV J.
Bharathiar University
Coimbatore

2. CONTENTS
• EYSENCK
• PERSONALITY
• EYSENCK’S MODEL
• HIERARCHICAL STRUCTURE
• BIOLOGICAL UNDEPINNINGS
• PSYCHOPATHOLOGY AND EYSENCK’S THEORY
• RESEARCH TECHNIQUES

3. HANS EYSENCK (1916-1997)
• Born in Germany, in 1916
• Refused to join Nazi regime and moved London at the age of 18
• Joined University of London
• Received his Ph.D. in 1940 in Psychology
• Worked as a research psychologist examining the reliability of psychiatric diagnosis at Mill Hill
Hospital during WORLD WAR II.
• Eysenck was Professor of Psychology at the Institute of Psychiatry, King's College, London
• Awarded chair of psychology at University of London in 1955
• Awarded Distinguished Scientist Award of APA in 1988

4. •Eysenck was the founding editor of the journal Personality and Individual
Differences, and authored more than 40 books and 700 articles.
•He was the most cited living psychologist until he died 1998
•He used questionnaires, self-ratings, rating by others, objective behavioral tests,
assessment of physique, physiological measurements, biographical and other
historical information as means of methods of data collection.
•He is critical of other psychologists to the point of sarcasm.
•Sense and Non-sense in Psychology, The Inequality of Man etc. are controversial
books written by Eysenck.

5. PERSONALITY
The sum-total of actual or potential behaviour patterns of
organism as determined by heredity and environment; it originates
and develops through the functional interaction of four main
sectors into which these behaviour patterns are organised: the
cognitive sector(intelligence), the conative sector(character), the
affective sector(temperament) and somatic structure(constitution).
Eysenck , 1947

6. EYSENCK’S
MODEL OF PERSONALITY
• Strongly rooted in biology
• Eysenck believed personality traits are heritable and had a psycho-
physiological foundation
• The three main traits, according to Eysenck were
• Extraversion - Introversion (E)
• Neuroticism - Emotional stability(N)
• Psychoticism

7. • Extraversion can be defined in behavioural terms, as the various traits that correlated
together to define this factor are, traits such as sociability, impulsiveness, activity,
carelessness, liveliness, jocularity and so forth.
( Eysenck, 1976)
• Neuroticism is conceived as strong, labile emotionality, predisposing a person to
develop neurotic symptoms in case of excessive stress.
• He defined Psychoticism as being solitary, not caring for people, often troublesome
not fitting in anywhere, may be cruel and inhumane, lacking in feeling and empathy
and altogether insensitive, may hostile to others, even to his own kith and kin and
aggressive even to loved ones, liking for unusual things and disregard for danger.

8. HIERARCHICAL STRUCTURE
• Eysenck conceptualised each of these three traits (E, N & P) as sitting on
the top of their own hierarchy.
• At the top level, there is a super trait. Eg: Psychoticism
• In the second level there are narrow traits to each super traits.
Eg: Aggressive
• In the third level, there are habitual acts. Eg: Attacking

9. •In the base level there are Specific acts. Eg: Biting
others
•In his early research Eysenck found only two
factors, E and N
•Later he added P
•At last, he tried to include Intelligence as a fourth
dimension of personality.

10. EYSENCK’S HIERARCHICAL SYSTEM OF
EXTRAVERSION

11. EYSENCK’S HIERARCHICAL SYSTEM OF
NEUROTICISM

12. EYSENCK’S HIERARCHICAL SYSTEM OF
PSYCHOTICISM

13. TYPE
• EXTRAVERSION
TRAIT
• SOCIABILITY
HABITUAL
RESPONSE
• PARTIES
SPECIFIC
RESPONSE
• INVITING OTHERS

15. BIOLOGICAL UNDERPINNINGS
• Eysenck’s personality system has a biological foundation
• It has two aspects: HERITABILITY and IDENTIFIABLE PHYSIOLOGICAL
SUBSTRATES
• Personality dimensions should have reasonably high heritability. Behavioural
genetics studies confirm this is moderate in case of all the three dimensions (E, N
& P)
• Personality traits should have identifiable physiological substrates ie; one can
identify properties in brain and CNS corresponding to the traits.

16. •Extraversion- Introversion is linked with chronic levels of excitation in the cortex.
•Introverts are over aroused (ARAS) and easy to stimulate . So, they avoid situations
that are apt to overwhelm them.
•Extraverts are under aroused (ARAS) and thus difficult to stimulate. So, they seek
out exciting situations.
•Neuroticism is thought to reflex the degree to which Autonomic Nervous System
reacts to stimuli. The more reactive a person, the more Neurotic he is.
•Psychoticism is linked with high level of Testosterone and low level of MAO, a
neurotransmitter inhibitor.

17. PSYCHOPATHOLOGY AND EYSENCK’S
THEORY
• A theory of psychopathology emerges from Eysenck’s physiological interpretation of
personality
• A person who is high on neuroticism and introversion is at risk for anxiety disorders :
fears, phobias, obsessions and compulsions.
• A person who is high on extraversion and neuroticism is a candidate for psychopathy
(antisocial personality).
• Disorders do not occur automatically. They befall a person with appropriate
predisposition and environmental circumstances.
• People learn their problems. One’s personality helps him to learn some things more easily
than others and so, different personalities are linked with different problems.

18. • Trait and therapy are usually strange bedfellows. A trait is fixed
characteristics and belied to be resistant to change including therapy.
• But, Eysenck’s interest of behaviour modification follows naturally
from his theory of emotional disorders.
• He believed what has been learned can be unlearned.
• Traits represents predispositions to learn. As, individuals learn and
unlearn behaviours, their traits do not change ,although their behaviour
does.
• Eysenck thus called the trait , a vehicle of change.

19. RESEARCH TECHNIQUES
• Eysenck used the Factor Analysis technique in his research
• Because of the criticisms on factor analysis, he developed a method called
Criterion Analysis
• Unlike Cattel, he preferred to extract a rather small number of factors from
factor analysis.
• Like Guilford, he preferred orthogonal factors; Cattel preferred oblique
factors.

20. CONCLUSION
• EYSENCK PROPOSED A HIERARCHICAL MODEL OF
PERSONALITY WHICH IS STRONGLY ROOTED IN BIOLOGY
• THE MAJOR DIMENSIONS OF EYSENCK’S MODEL ARE
EXTRAVERSION, INTROVERSION AND PSYCHOTICISM
• EYSENCK BELIEVED THAT ALL PERSOANITY TRAITS ARE
CAUSED BY PREDISPOSITION AND ENVIRONMENT
• EYSENCK BELIEVED IN PERSONALITY MODIFICATION

21. KEY WORDS
• Personality
• Extraversion
• Neuroticism
• Psychoticism
• Heritability
• Orthogonal factors : factors in a matrix in factor analysis where row stands for original
factors and column stands for new factors
• Oblique factors : factors in new axes of factor space, but the degree of correlation allowed
among the factors is small.

22. POSSIBLE QUESTIONS
• Explain the Hierarchical model of Personality of Eysenck
• Explain the biological bases of Eysenck’s hierarchical structure of
Personality
• What are all the differences in physiology of Extraverts and Introverts
• Explain the roles of enzymes and neurotransmitters in personality
• Explain the influence of Eysenck’s theory in psychopathology.

23. REFERENCE
• Larsen, R.L. & Buss, D.M.(2005).Personality Psychology: Domains of
Knowledge About Human Nature.SecondEdition.533-563.
• Hall, C.S. & Lindsey, G.(1985).Introduction to Theories of Personality. John
Wiley &Sons. New York.436-455.
• Peterson, C.(1988).Personality. Harcourt Brace Jovanovich Publishers.
Florida.316-319.
• en.m.wikipedia.org/wiki/factor_analysis