Chapter 7
Physiological Approaches to Personality
1
© M. Guthrie Yarwood
Part Two. Biological Domain

Chapter 6: Do our genes influence our personality traits?

Chapter 7:Do our physiological systems (e.g.,
brain, peripheral nervous system) influence our
personality traits?

Chapter 8: How are personality traits adaptive
(Evolutionary Theory)?
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© M. Guthrie Yarwood
Chapter 7 Outline

Physiologically Based Theories of Personality

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
Recent Research

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Eysenck’s PEN Model
Gray’s RST Model
Zuckerman’s Sensation Seeking Theory
Cloninger’s Tridimensional Personality Model
Gray: Neurotransmitters and Brain Structures
Frontal Asymmetry
© M. Guthrie Yarwood
Eysencks’
PEN Model
Psychoticism
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Extraversion
© M. Guthrie Yarwood
Neuroticism
Eysenck’s PEN Model: ExtraversionIntroversion
ARAS admits
little
stimulation to
brain
ARAS admits
much
stimulation to
brain
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Feel underaroused
Feel overaroused
Seek
stimulation in
environment
Do not seek
stimulation in
environment
© M. Guthrie Yarwood
EXTRAVERT!
INTROVERT!
EPQ-R Items
Extraversion


Are you rather lively?
Are you a talkative person?
Psychoticism



Would being in debt worry you?
Do you take much notice of what people think?
Neuroticism



Does your mood often go up and down?
Are you an irritable person?
Lie



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If you say you will do something, do you always keep your promise
no matter how inconvenient it might be?
Have you ever blamed someone for doing something you knew was
really your fault?
© M. Guthrie Yarwood
Eysenck’s PEN Model: Optimal Level of
Arousal

Eysenck applied Optimal Level of Arousal (Hebb, 1955) to
further explain differences between E and I

Level of arousal that is just right for any given task

Varies by individual
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© M. Guthrie Yarwood
Performance Level
High
E
I
Low
Low
High
Level of Stimulation in Environment
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© M. Guthrie Yarwood
Testing PEN:

Performance


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Alpha Activity (measures low-levels of arousal; Gale, 1983)
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Mild Stimulation (caffeine; Bullock & Gilliland, 1993)
Moderate Stimulation (recorded traffic noise; Belogevic et al.,
2001)
I showed greater alpha activity than E.
Other studies: No differences in resting arousal
© M. Guthrie Yarwood
I/E, Music, and Performance

Music IV Conditions



No Music
High Complexity Instrumental
Low Complexity Instrumental

Personality (PEN): Introverted, Extraverted
DV = reading comprehension

Results



Extravert/Introvert performance not affected by music
condition
Other Research found effects for I
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© M. Guthrie Yarwood
Eysenck’s PEN Model: Testing the theory

No difference in resting levels

Introverts ARE more reactive to moderate levels of
stimulation than extraverts

Eysenck Revised – it’s arousability, not resting arousal!
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© M. Guthrie Yarwood
Match the Big Five Factors to the PEN
factors!
Extraversion
Psychoticism
Neuroticism
Extraversion
Conscientiousness
Neuroticism
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Agreeableness
Openness to Experience
© M. Guthrie Yarwood
Gray’s RST Theory: Sensitivity to Reward
and Punishment
3 Neural Systems
1. Behavioral Activation System (BAS)
2. Behavioral Inhibition System (BIS)
3. Fight-Flight-Freeze System (FFFS; previously, FFS)


Textbook: explains Gray’s original RST theory (Gray, 1972,
1975, 1990)

We will discuss his revised theory (Gray, & McNaughton
2000)
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© M. Guthrie Yarwood
Gray’s RST Theory: Individual Differences in
3 Systems
BAS
BIS
FFFS
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• IMPULSIVITY
• Motivate people to approach rewarding stimuli
• ANXIETY
• During goal conflict, activates BAS or FFFS
• FEAR
• Motivate people away from danger
© M. Guthrie Yarwood
3 Types of Goal Conflict

Approach-Approach


Avoidance-Avoidance
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Choose between 2 desirable goals
Choose between two undesirable goals
Approach-Avoidance
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Same goal is desirable and undesirable
© M. Guthrie Yarwood
Gray’s RST Theory: BIS Resolves ApproachAvoidance Goal Conflict
Reward > Threat
BIS engages BAS and inhibits FFFS
Approach Behavior
Conflict Resolved!
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© M. Guthrie Yarwood
Gray’s RST Theory: BIS Resolves ApproachAvoidance Goal Conflict
Threat > Reward
BIS engages FFFS and inhibits BAS
Avoidance Behavior
Conflict Resolved!
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© M. Guthrie Yarwood
Gray’s RST Theory: Physiological Systems
BAS
• Greater left front cortical activity
• Cerebral cortex, thalamus, striatum
BIS
• Greater right front cortical activity
• Brain stem, frontal lobe
FFFS
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• Sympathetic nervous system
© M. Guthrie Yarwood
Frontal
Asymmetry:
Does greater
activation on
one side of the
frontal lobe
explain
individual
differences in
personality?
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© M. Guthrie Yarwood
Right Frontal
Lobe = More
behavioral avoidance
than behavioral
activation
Left Frontal Lobe
= More behavioral
activation than
behavioral avoidance
Approach!
Avoid!
Extraversion
Neuroticism
BAS
BIS
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(Davidson 2002; Harmon-Jones & Allen,
1998 Zuckerman, 2005)
© M. Guthrie Yarwood
How does this relate to mental illness?

Left Asymmetry / BAS Activation


Impulsive, over-reactive to rewards
Right Asymmetry / BIS Activation

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Anxiety, over-reactive to punishers
© M. Guthrie Yarwood
High BIS? Low BIS? High BAS? Low BAS?

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Anxiety Disorders
Obsessive-Compulsive Disorder
Bipolar Disorders
ADHD
Conduct Disorder
Substance Abuse
Histrionic Personality Disorder
Avoidant Personality Disorder
Dependent Personality Disorder
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© M. Guthrie Yarwood
Gray’s RST Theory: Bringing It Together
High BAS




Extraversion
Positive Emotions
Impulsive; over-reactive to
rewards
Externalizing Disorders
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High BIS




Neuroticism
Negative Emotions
Anxiety; Overreactive to
punishers
Internalizing Disorders
© M. Guthrie Yarwood
Zuckerman: Sensation Seeking

Tendency to seek out thrilling, exciting activities, take
risks, avoid boredom

High sensation seekers:





less tolerant of sensory deprivation
Require much stimulation to reach optimal level of arousal
High need for stimulation in their daily lives
Zuckerman’s Sensation Seeking Scale-V (SSS-V)
4 Factors
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© M. Guthrie Yarwood
(Factors)
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© M. Guthrie Yarwood
High or Low Sensation Seeking?

Young or old?

Whites or Blacks?
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Religious or Not
Religious?


College or High School
Degree?
Divorced or Married?
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
Wisconsin or California?

US or France?

Saudi Arabia or Mexico?

Firstborns or laterborns?

Bipolar or Antisocial?
© M. Guthrie Yarwood
Sensation Seeking by US State

http://buzz.drkencarter.com/chart.html
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© M. Guthrie Yarwood
Zuckerman: Sensation Seeking and MAO


Physiological basis for sensation seeking
Monoamine Oxidase (MAO)

Enzyme that maintains a proper level of neurotransmitters

Too little MAO = too much neurotransmitter
Too much MAO = too little neurotransmitter

Negative Correlation b/w MAO level and SS

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© M. Guthrie Yarwood
Zuckerman: Sensation Seeking and MAO

High sensation seekers have low levels of MAO,

The low MAO, leads to less inhibition of other
neurotransmitters

Results in less control over behavior, thoughts, emotions
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© M. Guthrie Yarwood
Problems with measure? (Y/N Response)

TAS:



ES



I dislike all body odors.
I like some of the earthy body smells.
DIS



I prefer the surface of the water to the depths
I would like to go scuba diving.
I dislike “swingers” (people who are uninhibited about sex)
I enjoy the company of real “swingers”
BS


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The worse social sin is to be rude.
The worst social sin is to be a bore.
© M. Guthrie Yarwood
Zuckerman: Sensation Seeking and Big Five
Extraversion
Openness to
Experience
TAS
ES
Dis
BS
.30
―
―
―
―
.50
―
―
SSS
.34
.37
Note. NEO-PI-R used for Big Five measures
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(Aluja,
García,
© M. Guthrie
Yarwood
& García, 2003)
Overview: Neurotransmitters and
Personality

Individuals differences in levels of neurotransmitter cause
individual differences in personality.
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Dimension
Level of Neurotransmitter
Novelty Seeking
High Dopamine
Harm Avoidance
Abnormalities in serotonin.
Reward Dependence
Low Norepinephrine
© M. Guthrie Yarwood
Cloninger’s
Tridimensional Personality Model
Dimension
Novelty Seeking
(Active Dopamine)
Description
Individual differences in excitability, impulsiveness,
extravagance, disorderliness
Individual differences in worry, pessimism fear, shyness,
fatigability; tendency to avoid pain and anxiety
Harm Avoidance
(Inactive Serotonin)
Low = energetic, outgoing, optimistic
High = cautious, inhibited, shy, apprehensive; expect to
experience unpleasant events
Reward Dependence
(Inactive Norepinephrine)
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Individual differences in sentimentality, warm
communication, dependence; tendency to develop
strong emotional attachments; persistent in behaving in
ways that produce reward.
© M. Guthrie Yarwood
Active
Dopamine
Inactive
Serotonin
Inactive
Norepinephrine
↑ Response to
pleasurable,
exciting stimuli
↑ Response to
harmful,
unpleasant
stimuli
↑ Response to
stimuli previously
associated with
pleasure
High Novelty
Seeking
High Harm
Avoidance
High Reward
Dependence
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© M. Guthrie Yarwood
Gray’s Recent Research (DeYoung & Gray, in press)
Higher Levels of:
O
Serotonin
Dopamine
C
E
+
+
A
N
+
—
+
Testosterone
+
—
Norepinephrine
+
Oxytocin/
Vasopressin
Blood Glucose
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+
+
© M. Guthrie Yarwood
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© M. Guthrie Yarwood
Gray’s Recent Research (DeYoung
et al., 2010)
Big Five
Trait
Brain Structure
Corr. w/
Volume
C
Lateral prefrontal cortex
+
Keeping info in working memory and
executing planned action
E
Medial orbitofrontal
cortex
+
Processes info about rewards
A
Cingulate cortex
+
Increased ability to understand others’
thoughts (i.e. theory of mind)
—
Sensitivity to threat and punishment,
increased tendency to experience
negative emotion; reduced ability to
regulate emotions.
N
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Prefontal cortex;
hippocampus
Why?
© M. Guthrie Yarwood
Summary: Neurotransmitters and
Personality

Gray’s theory links individual differences in personality to



individual differences in levels of neurotransmitters and
Individual differences in the volume of brain structures
Frontal asymmetry is a promising area of research for
individual differences in personality

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Left-Dominant = tendency to approach
Right-Dominant = tendency to avoid
© M. Guthrie Yarwood
Summary and Evaluation




Study of personality can be approached biologically
Two ways to think about how physiological variables are
useful in personality theory and research…
Use physiological measures as variables that may be
correlated with personality traits
View physiological events as providing causal substrate for
personality trait
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© M. Guthrie Yarwood