CHAPTER 10
EYSENCK'S BIOLOGICAL
TYPOLOGY
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Hans Eysenck (1916-1998):
• Eysenck focused on normal and
pathological populations.
• He felt that many traits are biologically based and were shaped
by evolutionary forces (e.g., extraversion, neuroticism).
• • He used factor analysis to identify traits.
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Eysenck believes that the most fundamental personality
characteristics are largely inherited.
Also, Eysenck believes that all behavior is learned--he
advocates learning theory and the behavior therapies.
Thus, Eysenck is something of an anomaly in “trait”
personality psychology
Personality
• Typology - means of classifying behavior through the use of
continuous, highly abstract concepts (types) that encompass
clusters of correlated traits.
• For Eysenck, personality consists of acts and dispositions
organized in a hierarchical fashion in terms of their level of
generality.
• Types of Personality
– extraversion - individuals who have an outgoing and
sociable approach to life.
– neuroticism - emotionally unstable people
– psychotocism - individuals with severe disorders; they are
cruel, inhumane, hostile, egocentric, yet creative.
• creative geniuses are individuals who are often
psychotic.
– divergent thinking - geniuses and psychotics both
have the ability to think along many different paths,
to consider alternatives not ordinarily considered in
trying to solve problems.
– a lack of serotonin (chemical neurotransmitter in the
brain) and an excess of dopamine (neurotransmitter
in the brain) that, in excessive amounts, can reduce
cognitive inhibitions.
Inhibition Theory
• Explanation of behavioral differences on the basis of inhibitory
cortical processes that hinder nervous system arousal.
– Extraverts - relatively strong inhibitory processes and weak
excitatory processes.
– Introverts - strong excitatory processes and weak inhibitory
processes.
Arousal Theory
• Explanation of behavioral differences in terms of the interactions
between inherited levels of nervous system arousal and levels
of environmental stimulation.
Arousal Theory (cont.)
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Ascending Reticular Activating System (ARAS) - part of the central
nervous system located in the lower brain stem; it is involved in the
arousal of the cerebral cortex.
Autonomic Nervous System - part of the peripheral nervous system
usually not under the individual's voluntary control that regulates the
operation of internal organs and glands; it consists of sympathetic and
parasympathetic subsystems.
Extraverts - brains have lower innate levels of arousal and are less
responsive to stimulation.
Introverts - brains have higher innate levels of arousal and are more
sensitive to stimulation.
Examples of Research Findings - introverts performed more poorly on
a reading comprehension test while watching a TV drama than
extraverts; extraverts tend to consume more chocolate, coffee, tea, and
soft drinks than do introverts.
Arousal Theory (cont.)
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Neuroticism and Autonomic Activation
– visceral brain - parts of the brain that underlie emotional feelings
and expression; also known as the limbic system.
– neurotics have lower thresholds for activity in the visceral brain
and greater responsivity of the sympathetic nervous system
(division of the autonomic nervous system that mobilizes the body's
resources for action); thus, neurotics overreact to even mild forms
of stimulation.
Psychoticism and Hormones
– androgens - male sex hormones; in mammals, the principal one is
testosterone.
– maleness linked to antigens, and schizophrenics have antigens in
their bodies.
Personality Development
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Personality is to a large extent biologically based, but personality can
be shaped by the influence of the environment.
Personality Development (cont.)
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Heredity plays a large role in development; same 3 personality types
(extraversion, neuroticism, and psychoticism found in many cultures,
suggesting a strong genetic basis for personality
– Twin studies used as evidence for genetic basis of personality.
• monozygotic - twins who develop from the splitting of a single
fertilized egg (also called identical twins).
• dizygotic - twins that develop simultaneously from two
separate fertilized eggs (also called fraternal twins).
Personality Development (cont.)
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Role of Socialization
– Extraverts learn the rules of socialization less quickly and efficiently
than introverts; extraverts generally tend to be less socialized than
introverts; extraverts are more likely to show more antisocial
behavior and become criminals than introverts.
Intelligence is a major personality factor; largely genetic, but can be
shaped by learning environment.
– electroencephalogram (EEG) - recording of electrical activity in
the cerebral cortex obtained by means of electrodes placed on the
skull.
– evoked potentials - patterns of waves that occur in the brain
following its stimulation.
Therapeutic Assessment Techniques
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Relied on host of experimental techniques to study personality.
Therapeutic Assessment Techniques (cont.)
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Eyeblink Conditioning - classical conditioning paradigm in which a
tone is used as the conditioned stimulus, and a puff of air to the eye is
the unconditioned stimulus. Conditioning occurs when the conditioned
stimulus alone is sufficient to produce the eyeblink response.
Electrodermal Response - changes in the electrical conductance of
the skin that are associated with arousal.
Pupillary Response - changes in dilation of the pupils of the eyes
associated with arousal.
Research on Lower Animals.
Theory's Implications for Therapy
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Behavior therapy - multifaceted approach to the treatment of disorders
based on the principles of learning.
– counterconditioning - procedure often utilized for therapeutic
purposes, in which a conditioned response (CR) is weakened by
associating the stimulus (CS) that evokes it with a new response
that is antagonistic (incompatible) with the CR.
– modeling - demonstration of behavior by one person so that
another person can imitate it.
– flooding - form of behavior therapy in which the client is exposed
to the most intense stimuli that evoke fear, typically for prolonged
periods of time, in an effort to extinguish it.
– systematic desensitization - technique designed to reduce the
strong anxieties associated with various stimuli; the client is
gradually exposed to them and, at each level in the anxiety
hierarchy, learns new responses through counterconditioning.
Evaluative Comments
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Comprehensiveness - broad in scope.
Precision and Testability - generally precise and testable.
Parsimony - fails to meet the parsimony criterion; too simplistic.
Empirical Validity - much empirical support for Eysenck's arousal
theory, especially in regard to the behavior of extraverts and introverts;
much more work needs to be done for the neurotic and psychotic types.
Heuristic Value - theory is proving to be very stimulating to researchers,
not only in Great Britain, but in other countries as well.
Applied Value - considerable influence on researchers in cognitive
behavior therapy.