Chapter 7 Physiological Approaches to Personality © M. Guthrie Yarwood1.

© M. Guthrie Yarwood

Chapter 7

Physiological Approaches to Personality

1

© M. Guthrie Yarwood2

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)?


Chapter 7 Outline

Physiologically Based Theories of Personality Eysenck’s PEN Model Gray’s RST Model Zuckerman’s Sensation Seeking Theory Cloninger’s Tridimensional Personality Model

Recent Research Gray: Neurotransmitters and Brain Structures Frontal Asymmetry


Eysencks’ PEN Model

Psychoticism Extraversion Neuroticism


ARAS admits little

stimulation to brain

Feel under-arous

ed

Seek stimulation in environment

EXTRAVERT!

ARAS admits much

stimulation to brain

Feel over-aroused

Do not seek

stimulation in environment

INTROVERT!

Eysenck’s PEN Model: Extraversion-Introversion


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 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?

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


Low

High

Low

High

Level of Stimulation in Environment

Perf

orm

an

ce

Leve

l

I

E


Testing PEN:

9

Performance Mild Stimulation (caffeine; Bullock & Gilliland,

1993) Moderate Stimulation (recorded traffic noise;

Belogevic et al., 2001)

Alpha Activity (measures low-levels of arousal; Gale, 1983) I showed greater alpha activity than E.

Other studies: No differences in resting arousal


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

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!


Match the Big Five Factors to the PEN factors!

Extraversion

Neuroticism

Conscientiousness

Agreeableness

Openness to Experience

Psychoticism

Extraversion

Neuroticism

Gray’s RST Theory: Sensitivity to Reward and Punishment


3 Neural Systems1. 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)

Gray’s RST Theory: Individual Differences in 3 Systems


• IMPULSIVITY• Motivate people to approach

rewarding stimuliBAS• ANXIETY• During goal conflict, activates BAS or

FFFSBIS• FEAR• Motivate people away from dangerFFFS


3 Types of Goal Conflict Approach-Approach

Choose between 2 desirable goals

Avoidance-Avoidance Choose between two undesirable goals

Approach-Avoidance Same goal is desirable and undesirable

Gray’s RST Theory: BIS Resolves Approach-Avoidance Goal Conflict


Reward > Threat

BIS engages BAS and inhibits FFFS

Approach Behavior

Conflict Resolved!

Gray’s RST Theory: BIS Resolves Approach-Avoidance Goal Conflict


Threat > Reward

BIS engages FFFS and inhibits BAS

Avoidance Behavior

Conflict Resolved!


Gray’s RST Theory: Physiological Systems

•Greater left front cortical activity•Cerebral cortex, thalamus, striatumBAS•Greater right front cortical activity•Brain stem, frontal lobeBIS•Sympathetic nervous systemFFFS


Frontal Asymmetr

y: Does

greater activation

on one side of the

frontal lobe explain

individual differences

in personality?


Left Frontal Lobe = More

behavioral activation than

behavioral avoidance

Right Frontal Lobe = More

behavioral avoidance than

behavioral activation

Avoid!

(Davidson 2002; Harmon-Jones & Allen, 1998 Zuckerman, 2005)

Extraversion

Approach!

Neuroticism

BAS BIS


How does this relate to mental illness? Left Asymmetry / BAS Activation

Impulsive, over-reactive to rewards

Right Asymmetry / BIS Activation Anxiety, over-reactive to punishers


High BIS? Low BIS? High BAS? Low BAS?

Anxiety Disorders Obsessive-Compulsive Disorder Bipolar Disorders ADHD Conduct Disorder Substance Abuse Histrionic Personality Disorder Avoidant Personality Disorder Dependent Personality Disorder

Gray’s RST Theory: Bringing It Together

High BAS High BIS


Extraversion Positive Emotions Impulsive; over-

reactive to rewards Externalizing

Disorders

Neuroticism Negative Emotions Anxiety;

Overreactive to punishers

Internalizing Disorders

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


(Factors)


High or Low Sensation Seeking? Young or old?

Whites or Blacks?

Religious or Not Religious?

College or High School Degree?

Divorced or Married?

Wisconsin or California?

US or France?

Saudi Arabia or Mexico?

Firstborns or laterborns?

Bipolar or Antisocial?


Sensation Seeking by US State http://buzz.drkencarter.com/chart.html

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

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


Problems with measure? (Y/N Response) TAS:

I prefer the surface of the water to the depths I would like to go scuba diving.

ES I dislike all body odors. I like some of the earthy body smells.

DIS I dislike “swingers” (people who are uninhibited about

sex) I enjoy the company of real “swingers”

BS The worse social sin is to be rude. The worst social sin is to be a bore.


Zuckerman: Sensation Seeking and Big Five

31

TAS ES Dis BS SSS

Extraversion

.30 ― ― ― .34

Openness to Experience

―.50 ― ― .37

(Aluja, García, & García, 2003)

Note. NEO-PI-R used for Big Five measures

Overview: Neurotransmitters and Personality


Individuals differences in levels of neurotransmitter cause individual differences in personality.

DimensionLevel of

Neurotransmitter

Novelty Seeking High Dopamine

Harm AvoidanceAbnormalities in

serotonin.

Reward Dependence Low Norepinephrine


Dimension Description

Novelty Seeking(Active Dopamine)

Individual differences in excitability, impulsiveness, extravagance, disorderliness

Harm Avoidance(Inactive Serotonin)

Individual differences in worry, pessimism fear, shyness, fatigability; tendency to avoid pain and anxiety

Low = energetic, outgoing, optimistic

High = cautious, inhibited, shy, apprehensive; expect to experience unpleasant events

Reward Dependence(Inactive Norepinephrine)

Individual differences in sentimentality, warm communication, dependence; tendency to develop strong emotional attachments; persistent in behaving in ways that produce reward.

Cloninger’s Tridimensional Personality Model


Active Dopamine

↑ Response to pleasurable,

exciting stimuli

High Novelty Seeking

Inactive Serotonin

↑ Response to harmful,

unpleasant stimuli

High Harm Avoidance

Inactive Norepinephrin

e

↑ Response to stimuli previously associated with

pleasure

High Reward Dependence


Higher Levels of: O C E A N

Serotonin + + —

Dopamine+ +

Testosterone+ —

Norepinephrine+

Oxytocin/Vasopressin

+

Blood Glucose +

Gray’s Recent Research (DeYoung & Gray, in press)


Gray’s Recent Research (DeYoung et al., 2010)

Big Five Trait

Brain Structure Corr. w/ Volume

Why?

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)

N Prefontal cortex; hippocampus —

Sensitivity to threat and punishment, increased tendency to experience

negative emotion; reduced ability to regulate emotions.


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 Left-Dominant = tendency to approach Right-Dominant = tendency to avoid

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

Chapter 7 Physiological Approaches to Personality © M. Guthrie Yarwood1.

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Transcript of Chapter 7 Physiological Approaches to Personality © M. Guthrie Yarwood1.