Transcript Chapter Seven

Chapter Seven
Biological Processes and
Personality
Extraversion
• Hans Eysenck—level of extraversion/
introversion reflects differences in cerebral
cortex activation
•
Introverts
Extraverts
– Higher basal cortical activation
•Lower basal cortical activation
– More alert when nothing happening •Less alert when nothing
happening
– Withdraw to avoid overstimulation •Seek stimulation to elevate
arousal
– Fewer mistakes on tasks requiring •More bored by repetitive tasks
vigilance
– Require more depressant drugs to •Require more stimulants to reach
reach given index of unalertness
given level of arousal
Neuroticism
• High neuroticism reflects easily aroused
emotion centers in the brain
– Emotional arousal exaggerates behavioral
responses of introverts and extraverts
Behavioral Approach System (BAS)
• Regulates movement toward desired states or
objects (incentive)
• Responsible for positive emotions (left prefrontal
cortex)
• Relates to conditioning involving positive
outcomes, but not negative outcomes
• People with different levels of BAS sensitivity
demonstrate differences in behavioral and
emotional responses to incentives
• May be related to dopamine activity
Behavioral Inhibition System
(BIS)
• Regulates movement away from undesired states
or objects
• Associated with anxiety (right prefrontal cortex)
• Relates to conditioning involving negative
outcomes, but not positive outcomes
• People with different levels of BIS sensitivity
demonstrate differences in behavioral and
emotional responses to punishment
• May be related to serotonin and/or GABA activity
Approach/Inhibition and Traits
• BIS-related neuroticism/emotionality
– Anxiety at core of emotionality
– High BIS-sensitive people respond to anxiety
manipulations
• BAS-related to extraversion
– High BAS-sensitive people respond to positive
mood manipulations
Areas of Disagreement
• Social qualities of extraversion?
– Perhaps it’s useful to think of social incentives as an
important class of rewards to which extraverts are
drawn in order to experience positive affect
• Role of impulsivity
– Is it linked to extraversion?
– Is it a separate trait (the flip-side of
conscientiousness)?
– Another view—impulsivity with positive affect belongs
with extraversion
– Impulsivity items do not load with BAS or extraversion
items in a factor analysis
Sensation Seeking
• Marvin Zuckerman
• High sensation seekers are in search of new, varied, and
exciting experiences
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Drive faster
More likely to use drugs and increase alcohol use over time
More high-risk sports
More risky antisocial behavior
More sexually experienced and responsive
More dissatisfied with relationships
• Monoamine Oxidase (MAO)
– Related to levels of sensation seeking
– Also associated with social dominance, aggression, and gene
linked to impulsivity
Function of Sensation Seeking
• Regulates exposure to stimulus intensity
– High sensation seekers (HSS) open
themselves up to stimulation
– HSS do well in overstimulating conditions
– Low sensation seekers (LSS) adapt better to
most ordinary circumstances, but may shut
down under intense conditions
– Impulsive unsocialized sensation seeking
(IUSS) —inability to inhibit behavior
appropriate to social constraints
Impulsiveness
• Issue: How best to account for impulsiveness
• Approach and inhibition systems
– High BAS
– Low BIS
– Combination (high BAS and low BIS)
• Serotonin
– Most studies relate serotonin to negative emotion
– Low serotonin function associated with anger,
impulsive aggression
– Serotonin levels positively related to
conscientiousness
– Suggestive that impulsiveness derives from a
separate biological system
Hormones and Personality
• Testosterone:
– Higher prenatal levels weeks 8-24, months 1-5 after
birth, and after puberty for normal males
– Developmental default is female
– Exposure to androgens results in male physical and
neurological development
– Exposure to higher levels of prenatal androgens:
• Associated with higher self-reported physical aggression scores
in response to hypothetical situation (boys and girls)
• Associated with cross-gender toy selection among girls
Testosterone and Adult Personality
• Focus on associations with dominance and
antisocial behavior
– Positive associations with:
• Violation of prison rules among inmates and likelihood of
having committed violent crime
• Veterans’ trouble with parents, teachers, and classmates
when growing up (increased effects among low SES)
• Being a trial lawyer, actor, NFL football player
• More dominant and confident social interactions
• Not being married, getting divorced, having an affair, and
domestic abuse among men
– Factor analysis with personality items—testosterone
data loaded with impulsiveness, sensation seeking,
and dominance
Cycles of Testosterone Action
• Testosterone rises after:
– Success in a competitive event
– Your team wins
– Sexual intercourse
– Challenged by insult
• Testosterone falls after:
– Failure or humiliation
– Your team loses
Testosterone, Dominance,
and Evolutionary Psychology
• Males: Overt aggressiveness helps confer
dominance and status increasing reproductive
advantage
• Females: No advantage for aggressiveness in
females and may interfere with reproductive
success and child rearing activities
• Irony: In today’s society, dominance and status
are defined in greater socioeconomic terms.
High levels of testosterone may interfere with
socioeconomic advancement
Men, Women, and Oxytocin
• In response to threat, animals engage “fight or flight”
response
– Most research demonstrating this effect was done with males
• Different response may be activated for females—“tend
and befriend”
– Reflects differing evolutionary pressures on males and females due to
offspring investment (i.e., not effective to fight when pregnant or caring
for an infant)
– Derived from systems that produce bonding between infant and
caregiver
• Oxytocin—hormone resulting in relaxation, calming,
mother-infant bonding, general social bonding, and adult
pair-bonding in some species
– Females typically have higher levels than men
– Androgens inhibit release of oxytocin under stress; estrogens activate
release
– Released during orgasm, childbirth, massage, and breast-feeding
Assessment
• Assessment tied to biological processes
– EEG—measures of electrical brain activity
– PET—mapping of brain activity from
metabolic function
– MRI—images of brain function from magnetic
fields created from neural activity
• Functional MRI—assesses levels of activation at
rest and during mental activity
Problems in Behavior
• Anxiety—indicative of oversensitive BIS
activity
• Depression
– High BIS activity
– Weak BAS activity
• Antisocial personality
– High BAS activity
– Low BIS activity
– Third system—sensation seeking, low MAO, high
testosterone
Therapy
• Modifying biological function may change
manifestation of disorders
• Pharmacotherapy—drug administration
– Antianxiety drugs
– Antidepressants (SSRIs)
• If drug therapy changes personalities,
what are the implications for the way we
view the construct?