Hans Eysenck was a German psychologist who developed a personality theory based on three traits: Psychoticism, Extraversion, and Neuroticism. These traits exist on continua and are influenced by genetics. Eysenck conducted studies using twins and brain imaging to support the biological basis of personality. He proposed a hierarchical model of personality with acts organizing into habits, traits, and factors. While popular, Eysenck's theory has been criticized for its lack of evidence and for questioning the predictive power of traits. Overall, the theory provided a descriptive and causal explanation of personality that has influenced many other theories.

1. INTRODUCTION
Hans J. Eysenck was born in Germany in 1916. He left Germany for France in 1934 and eventually established a life for himself in Britain. Eysenck was one of
the first psychologists to relate biology to personality and has developed an extensive range of theories on many topics and published over 40 books, many of
which he has co-written with his wife Sybil B.G. Eysenck. He has also completed publications with his son Michael W. Eysenck; a psychologist who specialises in
memory. Hans Eysenck decided to retire in 1983 but continued writing until he died in September 1997. Eysenck’s Trait Personality Theory is based on
biological explanations (Eysenck, 1990). Eysenck believed that an individual’s personality traits, or what Eysenck referred to as ‘temperament’, are caused
directly by a person’s genetic make-up (Chamorro-Premuzic & Furnham, 2005). There have been many studies that support biological explanations of Eysenck’s
trait personality theory; these include, twin studies (Eaves & Eysenck, 1975, and Eysenck, 1990) and brain imaging (Canli et al., 2001).
STABILITY
EYSENCK’S 3 MAIN PERSONALITY TRAITS
Eysenck created a model of personality traits, it initially consisted of the
continuums of Extraversion and Neuroticism, later adding Psychoticism creating
the PEN Model (Eysenck, 1990).
EXTRAVERSION INTROVERSION
The three traits are on a spectrum:
Psychoticism → Ego Control
Extroversion → Introversion
Neuroticism → Stability
UNSTABLE
Eysenck believes everyone exists somewhere on the spectrum of all three
personality traits.
EXTRAVERSION
PSYCHOTICISM NEUROTICISM
The extraversion dimension is widely seen as a
The psychoticism dimension is a Last is neuroticism. Individuals exist on this spectrum continuum ranging from extroversion to
more recent addition and is less to varying degrees. Eysenck (Matthews & Gilliland, introversion (Maltby & Macaskill , 2010).
well defined than neuroticism and 1999) claims that neurotics are best explained as
extraversion. Psychoticism is at individuals who are unstable. Those HIGH on extroversion (extroverts) are:
one end of the continuum and • Sociable
super-ego control is at the other Those HIGH on neuroticism (emotionally unstable) • Impulsive
(Carducci, 2009) are: • Like Excitement
• Exaggerated or unsubstantiated fears, including • Directed towards external reality
Those HIGH on psychoticism are: objects, places, animals or even certain individuals • Lively
• Non-conformist • Impulsive or obsessive behaviours • Active
• Tough-minded • Excess fear and anxiety • Assertive
• Willing to take risks • Depression • Sensation-Seeking
• Unconcerned about the rights • Feelings of guilt • Carefree
and welfare of others • Low self-esteem • Dominant
• May engage in antisocial • Tension
behaviours • Irrationality Those LOW on extroversion (introverts) are:
• Less sociable
Those LOW on psychoticism are: Those LOW on neuroticism (emotionally stable) are: • Quiet
• Warm • Calm • Introspective individuals
• Sensitive • Even-tempered • Directed towards inner reality
• Concerned about others • Less likely to feel tense • Like to live a well ordered life
EYSENCK’S HIERARCHICAL TRAIT THEORY
Eysenck describes personality in a hierarchy of constructs. Acts are organised into Habits, then to Traits, FACTOR
then to Factors (Eysenck, 1990).
HEL
P!
TRAIT
TRAIT
For Example
Act – Buy food
Habit – Buy food for party
HABIT
HABIT
HABIT
Trait – Has party’s frequently and is often seen with groups of people
Factor – They are on the extravert side of the extraversion–introversion continuum ACT
ACT
ACT
STRENGTHS OF THE THEORY
WEAKNESSES OF THE THEORY
The PEN model is a combination of descriptive and causal aspects of personality, which makes it
Eysenck’s theory, although extremely popular, has more distinct than other theories, such as the Five Factor Model (Costa & McCrae, 1992: Eysenck,
however been criticised due to its failure to produce 1991). The Pen model offers causal explanations, as well as simply describing personality traits.
evidence that introverts and extroverts condition
differently, (Gross,R, 2009). The PEN model offers clear and concise levels, which are easy to understand and do not over lap
each other like other models do. The PEN model discriminates intellectual processes from
There has also been criticisms in the usefulness of a emotional ones (Eysenck & Eysenck, 1985).
trait approach theory to personality, some suggesting
that personality traits are not a good predictor of The PEN model offers a strong experimental approach to the study of personality, which means it
future behaviours (Mischel, 1973) is a testable theory and as a result of this has served as a good role model for many other
personality theories (Eysenck & Eysenck, 1985).
Eysenck’s Personality Questionnaire (EPQ) was
“PORKY PIG” “TAZ-MANIA”
criticised by Heim (Heim, 1970, as cited in Gross, “DAFFY DUCK”
“BUGS BUNNY”
WHICH • Hostile
1990). She stated that yes and no questions could CHARACTER
ARE YOU?
•
•
Very self aware
Quiet and reserved
•
•
Warm
Cheerful • Reckless
not possibly be thorough enough to even begin to • Anxious in large groups
• Learns well through
• Talkative • Lacks
Common
• Moody • Enjoys being
understand the many different aspects of personality. • Jealous
observation centre Sense
• Tends to keep of attention • Shows 1916
• Envious emotions • Seeks novelty inappropriate -­‐199
private and excitement emotional
expression 7