Week 4: Chapter 7 Biological Processes and Personality

Chapter 7: Biological Processes and Personality

• 7.1 Eysenck's Theory: Eysenck's theory proposes the brain processes underlie extraversion and neuroticism.
• 7.2 Basic Approach System: A basic approach system affects personality.
• 7.3 Basic Avoidance System: A avoidance system affects personality.
• 7.4 Approach and Avoidance Systems: Approach and avoidance systems are related to traits and temperaments.
• 7.5 Third Basic System: A third basic system in personality can result in variations in restraint versus impulsiveness.
• 7.6 Hormones on Personality: Testosterone and oxytocin influence personality.
• 7.7 Biological Methods: Electroencephalograms and neuroimaging are biological methods for assessing personality.
• 7.8 Anxiety and Antisocial Behavior: Anxiety problems and antisocial behavior may be based in biology.
• 7.9 Progress in Biological Approach: Progress in the biological process approach to personality depends on advances in other fields.
• Personal Example: Lisa craves adventure and has many friends and activities. Her boyfriend prefers less intense activities.
• Human Capabilities: Humans have the characteristics implied by membership in the animal kingdom, including eating, drinking, and breathing.
• Introversion and Extraversion: Introverts are quiet and reserved, while extraverts are outgoing and uninhibited. Eysenck links this to differences in cortical arousal.
• Neuroticism: Eysenck considers neuroticism as a trait rooted in the body.
• Brain Activity: Introverts have higher baseline cortical arousal, avoiding overstimulation; extraverts seek stimulation.
• Introverts and Extraverts in Tasks: Introverts do better at tasks requiring monitoring of slowly changing visual displays (like air traffic control).
• Neuroticism Neural Basis: People high in neuroticism have easily aroused emotion centers.
• Approach System: A set of brain structures involved in approaching incentives is presumed to be involved when pursuing an incentive.
• Positive Emotions: The BAS is also associated with positive emotions like hope, eagerness, and excitement.
• Brain Activity Measures: Methods for recording electrical activity on the scalp include EEG, whereas newer imaging techniques (PET scans/fMRIs) record metabolic activity in different brain areas.
• Biological Trait Dimensions: Eysenck found neuroticism and extraversion to be two supertraits. Newer models include a third factor.
• Approach Sensitivity: Approach system is linked to left prefrontal cortex activity, predicting positive responses to happy stimuli.
• Avoidance System: The avoidance system is linked to right prefrontal cortex activity and predicts negative responses to fearful/disgust-inducing stimuli; it is also responsive to cues for punishment and danger.
• Relationship to Personality Traits: Anxiety/Neuroticism is associated with the avoidance system, while extraversion/Sociability is associated with the approach system.
• Incentive Sensitivity Measures of BAS sensitivity predicted speed at reward learning in a conditioning task.
• Neurotransmitters: Dopamine is linked to the approach system, with higher dopamine reactivity related to higher levels of positive emotionality, novelty seeking, and aspects of extraversion.
• Serotonin: Related to threat sensitivity
• Norepinephrine: Associated with panic and responses to stress, particularly in relation to anxiety.
• Neurotransmitter Relationships: Evidence suggesting correlations between neurotransmitters and personality traits is complex.
• Hormones: Testosterone and oxytocin are discussed as having influences on personality.
• Early Hormonal Exposure: Early hormone exposure (prenatal or otherwise) can influence later behavior.
• Hormones & Sex Differences: Differences in androgen exposure prenatally impacts brain development, potentially affecting behavior and personality.
• Hormones and Emotions Testosterone influences dominance, aggression, and perhaps, relationships and social interactions.
• Individual Differences in Hormones Differences in testosterone levels reflect individual variations in personality characteristics.
• Biological Assessment Methods: Electroencephalograms (EEGs), Positron Emission Tomography (PET), and Magnetic Resonance Imaging (MRI) are methods to assess personality traits.
• Biological Bases of Anxiety/Depression: Anxiety and depression can be linked to a person's avoidance system sensitivity and/or approach system weakness, respectively.
• Biological Basis for Antisocial Personality: Antisocial personality is linked to impulsivity and an inability to restrain antisocial behaviors.

7.5 Sensation Seeking

• Definition: People high in sensation seeking crave new, varied, and exciting experiences.
• Behavioral Tendencies: This includes faster driving, drug use, skydiving, and engaging in risky activities; sometimes associated with impulsivity and a lower sensitivity to threat.
• Role in Personality: This trait has links to aspects of personality and relates to brain functions.

7.6.1 Hormones and the Body/Brain

• Hormone Effects: Hormones affect brain development and functioning, potentially impacting future behavior.
• Development: Normal males have higher testosterone levels than normal females throughout development, including prenatal stages.
• Sex Differences Testosterone exposure in fetuses shapes the brain in differing ways. This may affect behaviour and personality.
• Masculinity/Femininity: This also includes a variety of hormone related behaviors across genders.

7.8 Anxiety and antisocial behaviors

• Biological Roots: Anxiety is linked to sensitivity of the avoidance system, while depression may reflect a weakness in the approach system.
• Biological Responses: Biological responses to stress can influence emotional states leading to certain types of behaviors
• Antisocial Personality: Impulsivity and restrained sensitivity to the threat system are linked to antisocial personality traits.
• Low MAO: Low MAO levels interact with adverse childhood environments to increase antisocial behavior.