Transcript EYSENCK’S THEORY OF PERSONALITY

PERSONALITY PSY234
Lecture 5:
Trait & Type approaches
Dr Simon Boag
Email: [email protected]
Readings
Carver, C. S. & Scheier, M. F. (2004).
Perspectives on Personality. (pp. 156-160)
• Monte, C. F. & Sollod, R. N. (2003). Beneath
the mask. (pp. 597-614)
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Additional (non-assessable)
• Eysenck, H. J. (1967). The Biological Basis of
Personality. Springfield: Thomas.
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McCrae, R. R. & Costa, P. T. (1997).
Personality trait structure as a human
universal. American Psychologist, 52, 509-516
Lecture Outline
I. Eysenck’s dimensional approach
• Extroversion vs introversion
• Neuroticism vs normality
• Personality temperaments
II. Biological basis of personality
• ARAS & visceral brain
III. Summary & evaluation
Learning Outcomes
After this lecture you should be able to:
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Understand & explain the meaning of
personality ‘type’, ‘trait’ & ‘dimension’
Describe & explain ‘extroversion’,
‘introversion’, ‘neuroticism’ & ‘normality’
Understand the relation of dimensions to
personality temperaments
Describe & explain Eysenck’s biological
explanation for personality differences
Types & Traits
Traits: An enduring characteristic of a
person’s behaviour
eg. sociable/unsociable
Types: A class of individuals with
common characteristic or pattern of
characteristics (physical/psychological)
eg.
Sheldon (1942) Varieties of Temperament
Personality Types
Hippocrates (460?-377?BC) & Galen (130200? AD): personality based on humors
Sanguine (blood)
• Warm-hearted, optimistic
Melancholic (black bile)
• Sad, depressed, anxious
Choleric (yellow bile)
• Quick tempered, angry, assertive
Phlegmatic (phlegm)
• Slow, lethargic, calm
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Eysenck’s Theory of Personality
Hans Eysenck (1916-1997)
Eysenck’s Approach
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Identifying universal, measurable
dimensions of personality
Rejects unique individual: “… the unique
individual is simply the point of
intersection of a number of quantitative
variables” (Eysenck, 1952, p.18).
Identified through large scale assessment
eg. US Airforce personnel
Statistical approach: Factor analysis
Personality Dimensions (1):
Introversion/Extroversion
Adapted from Jung’s types
Extrovert:
• Outgoing, embraces the world, responsive
to social & physical stimulation
• Insensitive to stimulation (‘stimulus
hungry’)
Introvert:
• Hesitant, reflective, withdraws from social
& physical stimulation
• Sensitive to stimulation (‘stimulus shy’)
Extroversion/Introversion
Dimension : relative degree (more or less)
Introvert X
Y
Z
Extrovert
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Extrovert: sociable, outgoing,
interactive, expressive, sensation seeking,
acts first, think later, dislikes being alone
Introvert: private, reclusive, reserved,
quiet, inward, sensitive, thinks before
acting, exhausted by groups
Personality Dimension (2):
Neuroticism/Normality
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Emotional vs non-emotional (Wundt)
Refers to strength of emotional reaction
not psychopathology
High degree of neuroticism:
• More emotionally reactive
• eg. moody, tense, anxious, irritable
High degree of normality:
• Less emotionally reactive (but still have
emotions)
Dimensions: Persons X & Y
Introversion/Extroversion:
Intr.
X
Y
Extr.
Neuroticism/Normality:
Neur.
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Y
X
These dimensions are orthogonal
Norm.
Test Items (EPQ)
Introversion/Extroversion
eg. ‘Do you prefer reading to meeting
people?’
Neuroticism/Normality
eg. ‘Are your feelings easily hurt?’
Later added another dimension:
Psychoticism (anti-social trait)
eg. ‘Would you like other people to be afraid
of you?’
Some empirical findings
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‘Criminals’ score high in E, N & P
(Eysenck & Eysenck, 1985)
Creative people score high on
psychoticism (Eysenck, 1993, 1994)
Extroverts more willing to have sexual
contact without commitment & report
more sexual experience (Wright &
Reise, 1997)
Eysenck’s Personality Types
Dimensional interaction produces ‘types’:
(1) Extrovert (neurotic):
Choleric: bad tempered
(2) Extrovert (normal):
Sanguine: cheerful
(3) Introvert (neurotic):
Melancholic: gloomy
(4) Introvert (normal):
Phlegmatic: unemotional, indifferent
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II. The Biological Basis of
Personality
Personality types result from differences in
central nervous system (CNS) functioning
Implications:
• Genetic basis of personality
• Relatively stable & unchanging
• However: environment interacts with
biological predispositions
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Biological Basis of
Extroversion/Introversion
ARAS system:
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Ascending Reticular Activation System
Cortical excitation & inhibition
High ARAS arousal:
• Predisposes to introversion
Low ARAS arousal:
• Predisposes to extroversion
Evidence: Introverts have higher sedation
threshold than extroverts (cf. ADHD)
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Some empirical findings
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Introverts less tolerant of painful
electric shocks (Bartol & Costello, 1976)
Corr et al (1995): After high dose of
caffeine: Introverts poorer performance
(over-stimulated?); Extroverts better
performance (stimulated?)
Frontal lobes of introverts more active
than extroverts (PET scan) (Johnson et
al, 1999)
Biological Basis of
Neuroticism/Normality
Visceral Brain (VB) system
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Hypothalamus & limbic system
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Mediates emotional activation
High VB activation:
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Predisposed to neuroticism (emotionally
reactive)
Low VB activation:
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Predisposed to normality (nonemotionally reactive)
Extroverts:
Normal & Neurotic
Sanguine
Normal Extrovert
• Low ARAS arousal
• Low visceral brain activity
Choleric
Neurotic Extrovert
• Low ARAS arousal
• High visceral brain activity
Introverts:
Normal & Neurotic
Phlegmatic
Normal Introvert
• High ARAS arousal
• Low visceral brain activity
Melancholic
Neurotic Introvert
• High ARAS arousal
• High visceral brain activity
Biological & Environmental
Interaction
“Biological causes act in such a way as to
predispose an individual in certain ways
to stimulation; this stimulation may or
may not occur, depending on
circumstances which are entirely under
environmental control”
(Eysenck, 1967, pp. 221-222)
• Effect of different teaching environments
III. Evaluation
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Twin studies: E & N: 50% genetic
Adoption studies: Correlations b/w
adoptive parents & adopted children for E
& N are around 0%
E, N & P: highest validity of all traits
(Kline, 1993)
Contradictory findings (eg. sedation
findings)
Hypothesised brain areas are not
independent of one another
Evaluation
Forms basis of subsequent trait theories
eg. ‘Big Five Factor model’ (McCrae &
Costa, 1997)
• Neuroticism, extroversion, openness,
conscientiousness, agreeableness
• Is personality really stable?
• Situationism (Mischel, 1990): situations
are strongest determinants of behaviour
• eg. child shy with strangers, friendly
with parents
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Summary
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Eysenck’s approach identifies personality
dimensions (ext/int; neu/nor)
A person’s placing on these dimensions
determines their personality temperament
Eysenck proposes a biological basis for
personality
Extroversion & introversion are said to be
related to ARAS functioning
Neuroticism & normality are said to be
related to visceral brain activity