1. Biological Processes and Personality
Chapter Seven
Biological Processes and Personality

2. 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

3. Neuroticism
High neuroticism reflects easily aroused emotion centers in the brain
Emotional arousal exaggerates behavioral responses of introverts and extraverts

4. 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

5. 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

6. 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

7. 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

8. Sensation Seeking Marvin Zuckerman
High sensation seekers are in search of new, varied, and exciting experiences
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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. 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?