Chapter 7

Biological Processes and Personality

Modified: 2022-07-15 6:33 pm

Being the biological creatures we are, it is only natural to consider our neural and hormonal mechanisms and the effects they have on our behavior and personality. Unfortunately, such a search is in its infancy but some progress has been made.

• Learning Objectives:
  • •7.1 Examine Eysenck’s theory that proposes that the brain processes underlie extraversion and neuroticism
    •7.2 Examine how the existence of a basic approach system would affect personality
    •7.3 Analyze how the existence of a basic avoidance system would affect personality
    •7.4 Examine how approach and avoidance systems are related to traits and temperaments
    •7.5 Explain how the assumption of a third basic system in personality can result in variation in restraint versus impulsiveness
    •7.6 Identify the influences of testosterone and oxytocin on personality
    •7.7 Describe the processes of electroencephalograms and neuroimaging as biological methods of assessing personality
• We are all animals. So, we must eat, drink, breathe, excrete, and sexually reproduce.
• Here, personality will be examined to the workings of the body.
• Still, the principles of similarity and difference still obtains and those differences come from the differences in activity of the nervous system and endocrine system.
• 7.1 Eysenck’s Early Views on Brain Functions (p. 87)
  • Recall (from chapter 4) Eysenck's supertraits: neuroticism and extraversion
  • He believed cerebral cortex activation explained differences in introversion and extraversion
    • Introversion: higher cortical arousal
    • Extraversion: less cortical arousal
  • Evidence for introversion/extraversion
    • Vigilance
      • Introverts better at vigilance
    • Drugs
      • Introverts need less stimulant (they are already alert)
      • Introverts need more depressant
  • Evidence for neuroticism
    • He thought those high in neuroticism have more easily aroused emotional brain centers
    • He thought emotional brain centers made introverts more introverted and extroverts more extroverted
• 7.2 Incentive Approach System (p. 87)
  
  • The functional approach emphasizes:
    • Parts of the brain
    • Brain chemicals
  • 7.2.1 Behavioral Approach
    • Behaviors include incentives and approach behavior
    • The Behavioral Approach System (BAS) is activated by incentives
      • AKA: activation system, behavioral engagement system, and behavioral facilitation system
    • Specific brain regions are likely involved in:
      • search for food
      • sexual behavior
      • general comfort
      • FYI, approach is necessary for BAS to work
    • Positive emotions
      • Anticipation of reward: hope, eagerness, excitement are related to BAS activation
    • Evidence
      • Higher left prefrontal cortex activated by incentives and positive feelings
      • Resting levels of BAS is associated with:
        • Positive response to happy films
        • Self-reported levels of BAS sensitivity
      • Extravert's brains have larger volumes in medial orbitofrontal cortex (extraversion and approach related physiologically)
        
  • 7.2.2 More Issues in Approach
    • Thwarted approach may lead to frustration and anger
    • Left frontal activation:
      • Desire for reward, leads to happiness
      • Reward denied or removed leads to anger and frustration
    • Learning
      • BAS associated with learning for positive outcomes
    • BAS
      • Reactive BAS is highly sensitive to incentives
      • Less reactive BAS do not respond as strongly to incentives
      • Melanie (high BAS) can't wait for co concert
      • Barbara (low BAS) is calm about concert
        
  • 7.2.3 Neurotransmitters and the Approach System
    • Neurotransmitters
    • Higher Dopamine Reactivity
      • Linked to higher positive emotionality
      • To novelty seeking
      • Extraversion
      • Social dominance
      • Enthusiasm
      • Energy
      • Assertiveness
      • Flexible goal shifting (distractibility)
      • Reward based learning
    • Learning vs Performance
      • Dopamine increases effort, not learning (in this view)
    • Activity and rewards
      • Increase in dopaminewhen event is better than expected
      • No change when when event is as expected
      • Decrease when event is worse than expected
• 7.3 Behavioral Avoidance, or Withdrawal, System (p. 89)
  • There exists an independent avoidance system too
  • It reacts to punishment and threats by inhibiting movement (like a brake pedal)
  • It is called the avoidance or withdrawal system
  • It is governed by the right prefrontal areas
  • Learning is for sensitivity to negative outcomes
  • The reactive avoidance system is:
    • Sensitive to threat
    • Related to accident proneness
  • Note that threat sensitivity and incentive sensitivity are fairly separate systems
  • Thus, many combinations of both (meaning various levels of each) are possible. One could be sociable AND fearful of social interactions at the same time
  • 7.3.1Neurotransmitters and the Avoidance System
    • Controversial area with mixed results
    • Serotonin, GABA, and norepinephrine are each candidates to explain:
      • Anxiety
      • Threat Sensitivity
      • Neuroticism
• 7.4 Relating Approach and Avoidance Systems to Traits or Temperaments (p.90)
  
  • There is considerable evidence that the brain's dual sydstems: approach and avoidance are real
  • Also, they correspond to information shown in previous chapters, specifically:
    • Avoidance links with neuroticism, anxiety, and threat sensitivity
    • Approach links with extraversion, activity, sociability, and social dominance
    • Brain volumes also correlate positively with both systems
    • 7.4.1 The Role of Sociability
      • Theorists disagree over the definition of extraversion in the context of approach
        • Table 7.1 (below) illustrates some of those differences
        • Some theorists argue over the difference between social quality and social incentives
        • Most note the social nature of human beings and argue that approach is innate
        • Reward sensitivity is proposed as an incentive, especially in the case of appetitive stimuli
          • Appetitive stimuli are those associated with the search for motivation (as opposed to the comsuption of it)--think of choosing a restaurant, that's appetitive while actually eating the food is consummatory.
            
    • 7.42 The Role of Impulsivity
      • Is impulsivity a component of extraversion?
      • Today, most theorists say no
• 7.5 Sensation Seeking, Constraint, and Effortful Control (p. 91)
  
  • Sensation seeking (and sensation avoidance) are two other oersonality factors to consider
  • What would you answer if I asked you to bungee jump off of a high bridge or parachute from several thousand feet in the air? If you said YES! then you are likely a sensation seeker. If you said NO WAY then you are likely a sensation avoider
    • 7.5.1 Sensation Seeking
      • Sensation seekers:
        • Drive faster
        • Are more likely to use drugs
        • Drink more alcohol over time
        • Participate in high-risk activities (bungee jumping and parachuting)
        • More sexually experienced
        • In the military, more likely to volunteer for a combat arm (infantry, armor, or artillery)
      • Theoretical explanations include:
        • Labelled: impulsive unsocialized sensation seeking (IUSS)
        • Sensation seekers work well in overstimulating environments
        • Sensation seekers may be disadvantaged in less demaning situations
        • Less likely to inhibit behavior in social situations
        • Focused more on immediate consequences vs longer term ones
        • May be related to antisocial personality disorder
          
    • 7.5.2 Relating Sensation Seeking to Traits and Temperaments
      • IUSS relates:
        • Inversely to agreeableness, conscientiousness, and constraint
        • Positively to neuroticism
      • Effortful control relates to:
        • Planfulness
        • Being focused
        • Restraint
        • Emerges in early adulthood
      • Impulse and Restraint are independent higher order traits
        
    • 7.5.3 Two Sources of Impulse and Restraint
      • Effortful Control adds a third variable to the dimensions of approach and restraint
      • For example:
        • Aids in not taking short term benefits and taking longer term ones
        • Helping people cope with unwanted situations (e.g., funerals)
          

• 7.5.4 Neurotransmitters and Impulse versus Constraint
  • Serotonin is involved in impulse control with low levels leading to impulsiveness and aggression. While high levels lead to conscientiousness
  • Earlier studies linked MAO (monoamine oxidase) to:
    • Sensation and novelty seeking
    • Dominance
    • Aggression
    • Drunk driving
    • Impulsivity
  • But MAO may only indicate serotonergic function
  • Experiments on humans where serotonin was lowered led to:
    • Hostility and aggressiveness
    • But only in people deemed aggressive already
    • So, serotonin may simply allow people to express their inborn traits and feelings
  • NEO-PI-R studies showed:
    • Only men were affected by low serotonergic levels
    • Low levels were associated with higher neuroticism
    • High levels were associated with conscientiousness (but also to lower positive feelings)
• Box 7.1 Research Question: How Do You Measure Neurotransmitter Function?
  • Studying and assessing neurotransmitter levels is not easily done
  • Researchers know that different people vary in their serotonin (and other hormones) sensitivity
  • The drug fenfluramine increases serotonin release and inhibits reuptake
  • It also causes the pituitary gland to secret prolactin
  • The level of prolactin is easily measured (as prolactin levels rise, serotonin levels fall)
• 7.6 Hormones and Personality (p. 94)
  • Sex hormones, especially testosterone, have effects on personality too
    • 7.6.1 Hormones, the Body, and the Brain
      • All fetuses are female at first
      • Testosterone in utero converts a female fetus into a male fetus
      • More subtle effects also exist:
        • Brain organization
        • Specific size differences in brain structures
        • Cortical integration
    • 7.6.2 Early Hormonal Exposure and Behavior
      • Early exposure to testosterone can affect subsequent behavior:
        • Self-reports of physically aggressive behavior (see Figure 7.2 below)
        • Playing with toys usually associated with the opposite sex (see Figure 7.3 below)
      • Sources of testosterone
        • From mother's medical treatment during pregnancy
        • Adrenal glands
        • From greater involvement in contact sports (for both boys and girls)

• 7.6.3 Testosterone and Adult Personality
  • In short, testosterone may form a personality factor centered around:
    • Impulsiveness
    • Sensation seeking
    • Dominance
  • Self-ratings include:
    • Cynical
    • Dominant
    • Sarcastic
    • Spontaneous
    • Persistent
    • Uninhibited
  • Many behaviors and characteristics are associated with high testosterone levels:
    • Violating prison rules
    • Violent crimes
    • Premeditated murder
    • More sex partners
    • More likely to abuse drugs and alcohol
    • More likely to go AWOL (absent without leave in the military)
    • Effects are higher among men with low SES
    • Trial lawyers higher in testosterone
    • Actors and pro football players higher in testosterone
    • Deeper voices in men
    • More quick to enter relationships
    • Less likely to marry
    • More likely to divorce
    • More likely to commit domestic abuse
  • Behaviors and characteristics associated with low testosterone levels
    • Ministers tend to show low testosterone levels
    • Those with low testosterone levels not happy in jobs commonly associated with high levels (and vice versa)
    • Men in low testosterone fraternities are friendly and smile often
      
• 7.6.4 Cycle of Testosterone and Action
  • Understand that testosterone levels vary over time and situations, so behavior, too, may vary
  • Testosterone levels rise:
    • After positive experiences
    • When insulted
    • Your team wins
    • After sexual intercourse
    • Playing with a gun
  • Testosterone levels fall:
    • After failure or humiliation
    • Your team loses
  • Behavioral outcomes include:
    • Increases promote sexual activity, dominance, and reward seeking
    • Decreases lead to lower assertiveness and avoidance of competition
  • In both situations (increase or decrease) a spiraling effect may follow
    
• 7.6.5 Testosterone, Dominance, and Evolutionary Psychology
  • Recall the principles of evolutionary psychology highlighted in chapter 6
    • Parental investment
      • Males increase reproductive success via increased numbers of matings
      • Females increase reproductive success by being choosy and looking for mates that will aid her during her longer period of parental investment
    • Aggressiveness
      • Helps males increase their reproductive success
      • Hinders females in several ways
        • Note, females are more likely to be perceived as "bitchy"
  • Counterproductive?
    • Are ancient biological and evolutionary patterns out of date now?
      • Male success today is favored more by SES than by physical dominance
        
• 7.6.6 Responding to Stress
  • Recent research suggests that the fight or flight response is not the only biological response to stress
  • Tending and Befriending are other possible responses, especially by women
    • Tending involves calming children and others in one's social group
    • Befriending is affiliating and bonding with others
      • It may derive from attachment
  • Oxytocin
    • Hormone related to relaxation and sedation
    • More of it in females
    • Androgens inhibit its effects
    • Estrogen promotes its effects
    • Released during:
      • orgasm, childbirth, massage, and breastfeeding
    • Promotes greater partner support
    • Promotes increase in trust
    • Promotes willingness to help strangers
    • Promotes increase in adhering to cultural norms
    • Personality effects are spotty at present
  • Evolutionary psychology supports those different responses by males and females
• Box 7.2 Steroids: An Unintended Path to Aggression
  • Many bodybuilders (male and female) use anabolic steroids
  • Those steroids are synthetic hormones that mimic testosterone
  • Because they are often used in large doses, in men they:
    • lower natural testosterone levels
    • lower sperm count
    • lower sex drive
  • In women, they:
    • shrink breasts
    • deepen voice
    • increase facial and body hair
  • Behaviorally, they:
    • cause bursts of anger (roid rage)
    • manic symptoms
    • depressive symptoms
    • aggression
• 7.7 Assessment from the Biological Process Perspective (p. 100)
  
  • Biological assessment is at an immature state and typically requires attached sensors or blood draws
    • 7.7.1 Electroencephalograms (EEGs)
      • EEGs measure global brain functioning via electrodes attached to the scalp
      • Billions of brain cells firing (or not firing) over time will cause brainwaves that can be recorded
      • Sleep studies typically use EEGs as do other studies of normal behavior
      • In terms of personality, EEGs have been used to differentiate incentive motivation vs avoidance motivation
        
    • 7.7.2 Neuroimaging
      • It is possible to assess brain activity and structure (including damage) in real time using neuroimaging techniques
      • The PET (positron emission tomography) scan analyzes the brains metabolic activity and creates a false color image similar to a weather map
      • The colors can indicate metabolic activity in different parts of the brain at a given time
      • The MRI (magnetic resonance imaging) scan uses a powerful magnet to create an image of the parts of the brain and surrounding structures
      • The magnet causes brain tissue and surrounding bone to resonate and those magnetic differences are made into an image
      • The fMRI (functional magnetic resonance) is a newer technique that can make MRI images in real time
    • Consequences
      • These techniques are used in diagnosis and in experimentation
      • For example, a person may be asked to read aloud or silently in a PET scan in order to see what parts of the brain are active under each condition
• 7.8 Problems in Behavior, and Behavior Change, from the Biological Process Perspective (p. 101)
  • 7.8.1 Biological Bases of Anxiety and Depression
    • The avoidance system combined with low constraint may cause high levels of anxiety
    • Depression, although not well understood, may be subject to hyperresponsiveness of emotions
      
  • 7.8.2 Biological Bases of Antisocial Personality
    • A number of hypotheses have been proposed for antisocial personality disorder:
      • Impulsivity
      • Inability to restrain antisocial urges
      • Overactive BAS
      • Deficits in the threat system
      • Sensation seeking
      • Insufficient endogenous MAO
    • Other biological factors such as testosterone may also be involved
      
• 7.8.3 Biological Therapies
  • Pharmacotherapy
    • Is the use of drugs to affect or alter brain functioning
    • Bipolar patients are given lithium
    • Schizophrenic patients are given drugs that lower dopamine levels
    • Depressed patients are given selective serotonin reuptake inhibitors (SSRIs)
  • Transcranial Magnetic Stimulation (TMS)
    • TMS is the local application of low or high frequency magnetic waves from outside of the skull to specific brain locations
    • TMS has been used for treating depression and for altering approach or avoidance behavior
• 7.9 Problems and Prospects for the Biological Process Perspective (p. 103)
  • FYI, my view is that we are still 300 years away from a full understanding of the brain and nervous system
  • So, your authors conclude, rightly, that this chapter does not describe a "fully developed personality theory"
  • There are many reasons for their statement:
    • Need to get information from other sciences
    • The newness of the field
  • Ultimately (300 years from now, perhaps) this may become the most important way to look at personality
    
• Summary (p. 103)
  • Eysenck pioneered the idea that brain processes were important to personality
  • Two systems: approach and avoidance have biological substrates
  • Impulsiveness and sensation seeking are components that varies among people
  • Hormones, specifically testosterone and oxytocin have major effects on behavior and personality
  • PET scans, MRI scans, and fMRI scans have contributed much to assessment but are only scratching the surface of the future
  • Problems in behavior and personality have been attacked by pharmacotherapy but questions remain about their long term effects
• Points to Remember
  • The idea that personality is tied to the biological functions of the body leads to a variety of possibilities involving the nervous system and the hormone system.
  • An initial approach of this sort was Eysenck’s theory that brain processes underlie extraversion and neuroticism. He argued that introverts are more aroused cortically than extraverts and that people high in neuroticism are more aroused emotionally than those low in neuroticism.
  • Others have taken a different path, relying on newer knowledge. It’s now often argued that personality rests on a behavioral approach system (BAS) that responds to incentives and an avoidance system that responds to threats.
  • Work on emotions suggests that the approach system involves (in part) the left prefrontal cortex and that the withdrawal system involves (in part) the right prefrontal cortex.
  • The threat system seems to represent the biological basis for the trait of neuroticism.
  • Some researchers suggest that the BAS represents the biological basis for extraversion.
  • Many people now believe it’s useful to assume that another biological system is responsible for variations in impulsiveness and sensation seeking (the tendency to seek out novel, complex, and exciting stimuli).
  • Sensation seeking relates to Eysenck’s psychoticism dimension and Tellegen’s constraint dimension, and both relate to the temperament of effortful control.
  • Variation in these qualities may be grounded in differences in the functions that cause people to take into account other people and long-term goals
  • Another aspect of the biological view on personality focuses on the influences of hormones on behavior.
  • Exposure to male hormones before birth can cause people years later to choose more aggressive responses to conflict and can increase girls’ preference for boys’ toys.
  • Testosterone in adults relates to dominance behavior, sometimes expressed in antisocial ways.
  • Testosterone also fluctuates with the context, increasing with challenges and victories and decreasing with failures.
  • An emerging area of work examines the possibility that another hormone, called oxytocin, is important in human social behavior.
  • Oxytocin appears to relate to female responses to stress, termed a tend-and-befriend response. The roots of this response may be in the attachment system, and it may relate to social bonding more generally.
  • The biological process approach to personality suggests that it may be possible to assess personality through biological functions. Although the attempt to do this is in its infancy, some researchers believe recordings of brain activity—particularly fMRIs—hold great promise for the future.
  • With regard to problems in behavior, high levels of threat sensitivity promote disorders involving anxiety. Either a high threat response or a low approach response may contribute to depression.
  • High approach–low avoidance can yield symptoms of antisocial personality, which also relates to impulsive sensation seeking and testosterone. This orientation to personality suggests that therapy based, in part, on medication is a means to bring about behavioral change. The idea is that medication can influence the underlying biological system, thereby altering the person’s behavior and subjective experience.

KEY TERMS

• Anabolic steroids: Chemicals that mimic the body’s tendency to rebuild muscle tissues.
• Antisocial personality: A person who displays impulsive action with little thought to consequences.
• Avoidance or withdrawal system: The part of the brain that regulates responses to punishment.
• Behavioral approach system (BAS): The part of the brain that regulates pursuit of incentives.
• Dopamine: A neurotransmitter believed to be especially important to approach regulation.
• Electroencephalogram (EEG): A record of overall electrical activity in higher regions of the brain.
• Functional magnetic resonance imaging (fMRI): Use of MRI to create a picture of activity inside the brain in different mental states.
• GABA: A substance, low levels of which appear to be linked to anxiety disorders.
• Impulsive unsocialized sensation seeking (IUSS): Trait involving the capacity to inhibit behavior in the
  service of social adaptation.
• Incentives: Things that people desire.
• Magnetic resonance imaging (MRI): A picture of activity inside the brain based on the brain’s electromagnetic energy.
• Monamine oxidase (MAO): A substance that helps regulate several neurotransmitters and seems to be involved in constraint over impulses.
• Neurotransmitter: A chemical involved in sending messages along nerve pathways.
• Norepinephrine: A neurotransmitter that some believe is important in anxiety responses.
• Oxytocin: A hormone that appears to be important in social bonding.
• Pharmacotherapy: A therapy based on use of medication.
• Positron emission tomography (PET): A picture of activity in the brain based on the brain’s metabolism.
• Sensation seeking: The tendency to seek out varied, unusual, and exciting stimuli.
• Serotonin: A neurotransmitter that some believe is involved in anxiety and others believe is involved in constraint over impulses.
• Testosterone: Male sex hormone that influences a wide range of behaviors.

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