Trait and Biological Perspectives
Introduction to Trait Perspectives
The trait perspective relies heavily on the correlational method.
Correlation is comparing two sets of measurements (variables) to see if they have any relationship.
Correlation
Correlation: Comparing two sets of measurements (variables) to see if they have any relationship or "co-relation."
Example: Comparing height and weight; taller people generally weigh more, but the correlation isn't perfect.
Perfect Positive Correlation (+1): Very close example is men's shoe size and foot length.
Shoe Size vs. Foot Length Example:
John: Shoe size 4 \frac{1}{2}, foot length 9 \frac{1}{4} inches
Dave: Shoe size 5, foot length 9 \frac{3}{8} inches
Sam: Shoe size 5, foot length 9 \frac{1}{4} inches
Jim: Shoe size 6 \frac{1}{2}, foot length 9 \frac{1}{2} inches
Ed: Shoe size 6 \frac{1}{2}, foot length 9 \frac{3}{4} inches
Bob: Shoe size 7, foot length 9 \frac{3}{4} inches
Ted: Shoe size 8, foot length 10 \frac{1}{8} inches
Matt: Shoe size 11 \frac{1}{2}, foot length 11 inches
Damian: Shoe size 12, foot length 11 \frac{1}{4} inches
Horton: Shoe size 14, foot length 11 \frac{3}{8} inches
Scatter Plot: A chart that visually represents the relationship between two variables.
A line of "best fit" describes the data, but may not be perfect due to variations (e.g., shoe sizes that are too tight or loose).
Perfect Negative Correlation (-1): Example is a car's fuel efficiency vs. the amount of money spent on gas per mile.
Zero Correlation (0): Example is shoe size vs. SAT score.
Real-Life Example: Comparison of homicide rates and hand gun ownership (late 1980s data).
Country | Homicide Rate (per 100,000 per year) | Hand Gun Ownership (% of population)
USA | 8.8 | 29.0
Northern Ireland | 5.2 | 1.5
Finland | 2.9 | 7.0
Canada | 2.1 | 4.0
Australia | 2.0 | 2.0
Scotland | 1.8 | 0.5
Belgium | 1.8 | 6.0
Switzerland | 1.2 | 14.0
Norway | 1.2 | 3.5
France | 1.2 | 5.5
West Germany | 1.2 | 6.5
Spain | 1.0 | 2.0
The Netherlands | 0.9 | 1.0
England and Wales | 0.7 | 0.5
Correlation: +0.70 (impressive; may reflect societal factors).
Switzerland's high gun ownership is due to army training and weapon maintenance requirements.
Northern Ireland's high homicide rate with low gun ownership suggests other factors at play.
Variance Explained: Squaring the correlation gives the percentage of variance in one variable explained by the other.
Example: 0.70 correlation means 49% of the variation in homicide rates is related to hand gun ownership.
Leaves 51% of the variation unaccounted for.
Psychological Significance: Correlations of 0.3 and higher are generally impressive in psychology; 0.8 or 0.9 are very strong.
Causality: Correlation does not imply causation.
Example: Grades and SAT scores correlate well, but it's unclear which causes which.
Homicide-hand gun example: A violent culture might lead to both more guns and more violence.
Experiments are needed to determine cause and effect.
Raymond Cattell and Essential Traits
Essential Trait Approach: Identifying the most important personality traits.
Lexical Criterion of Importance: The more words there are to describe a trait, the more important it is.
Cattell's Approach:
Started with 4500 personality trait words.
Reduced the list to 171 trait names.
Used self-ratings and factor analysis to examine them.
Factor Analysis:
Statistical technique used to identify underlying personality traits.
If characteristics correlate across people, they may reflect a basic underlying trait.
Traits that correlate positively suggest an underlying personality trait.
Traits that correlate negatively may be opposites on an underlying dimension.
Clusters of correlating items are called factors.
Cattell's Sixteen Personality Factors:
Cattell concluded there are 16 basic personality trait dimensions.
The 16PF (16 Personality Factors) test measures people on these dimensions.
Abstractedness: imaginative versus practical
Apprehension: insecure versus complacent
Dominance: aggressive versus passive
Emotional Stability: calm and stable versus high-strung
Liveliness: enthusiastic versus serious
Openness to Change: liberal versus traditional
Perfectionism: compulsive and controlled versus indifferent
Privateness: pretentious versus unpretentious
Reasoning: abstract versus concrete
Rule Consciousness: moralistic versus free-thinking
Self-Reliance: leader versus follower
Sensitivity: sensitive versus tough-minded
Social Boldness: uninhibited versus timid
Tension: driven and tense versus relaxed and easygoing
Vigilance: suspicious versus accepting
Warmth: open and warmhearted versus aloof and critical
The Big Five Theory
Most Commonly Discussed Theory: The Big Five Theory is the most empirically supported and widely discussed theory in the essential trait approach.
Early Evidence: D.W. Fiske (1949) found a five-factor solution instead of Cattell's sixteen.
Evolution of the Theory: Multiple researchers found similar results over decades.
Disagreement in Naming Factors:
Naming factors in factor analysis is difficult due to subjective interpretations of word meanings.
Factor appearance depends on the measures included in the study.
Commonly Used Names (McCrae & Costa, 1987):
Extraversion: Outgoing, assertive, sociable (opposite: Introversion).
Agreeableness: Social warmth, likability, nurturance, emotional supportiveness (opposite: Antagonism).
Conscientiousness: Responsible, organized, persistent, purposeful striving (opposite: Low Conscientiousness).
Neuroticism: Emotionally unstable, high anxiety (opposite: Emotional Stability).
Openness to Experience: Willingness to try new things, consider new ideas, open-minded (opposite: Low Openness).
NEO-PI-R Personality Test: This test measures on the five dimensions.
Superordinate Traits: The Big Five are considered superordinate traits with more specific traits within them.
NEO-PI-R includes measures of six specific traits within each of the Big Five (30 specific traits in total).
Scores for specific traits are combined into a single score for the superordinate trait.
Interpersonal Circumplex Model
Inspiration: Harry Stack Sullivan (1953), model by Timothy Leary (1957).
Revisions: Various researchers have proposed revisions (e.g., Benjamin, 1974; Kiesler, 1996; Strong, Hills, & Nelson, 1988; Wiggins, 1979).
Underlying Commonalities:
Personality in social situations can be understood using two basic dimensions: agency and communion.
Agency: dominating vs. submitting.
Communion: loving vs. ignoring.
Mapping Personality:
A person's level of agency and communion can be mapped on a two-dimensional space.
Leary (1957) argued that all other dimensions of personality are combinations of these two (not universally agreed upon).
Interpersonal Patterns:
Individuals repeat interpersonal patterns by acting in a specific manner and inviting complementary responses.
Complementary responses sustain natural interaction and allow events to unfold.
People invite complementary responses to affirm and validate their interpersonal style.
Behavior is designed to produce reactions that confirm perceptions, expectations, and construals of others and the self (Carson, 1982).
Complementarity
Operationalized: Complementarity is operationalized by a two-dimensional interpersonal circle (communion and agency).
Reciprocity on the agency dimension: dominating is complementary to submitting and vice versa.
Correspondence on the communion dimension: loving is complementary to loving, ignoring to ignoring.
Behavior Combination: Any behavior is a combination of communion and agency and has a complementary response that way.
Example: Acting in a loving and dominating manner invites a loving and submissive response.
Complementarity also occurs in the intensity of behavior (intense dominating invites intense submissive).
Applicability: Primarily applicable to naturally occurring, relatively unstructured interpersonal settings.
Applications: Examines individual differences in personality, influences on relationships (e.g., Sato & Gonzalez, 2009), and compatibility of personalities (e.g., Auerbach, Kiesler, Strentz, Schmidt, & Serio, 1994; Nowicki & Manheim, 1991).
Personality Assessment
Measuring Traits: Psychologists create instruments to measure personality traits.
Quality Criteria: Need to consider reliability and validity.
Reliability
Definition: Repeatable and yields consistent results.
Test-Retest Reliability (Temporal Stability):
Administer the test to the same group of people at least two times.
High correlation between scores indicates good test-retest reliability (range 0 to 1).
Helps confirm that the test measures a stable personality trait rather than something temporary.
Internal Consistency:
Administer the test to a large group of people.
Examine the correlations between responses to questions measuring the same trait.
Cronbach Alpha: Common way to calculate internal consistency (range 0 to 1).
Low internal consistency requires modifying the test by removing or replacing items.
Inter-Item Correlations: How each item correlates with the total scores of the remaining items.
Item-Total Correlations: Tells us how each item is correlated with the total scores of the remaining items in the measure.
Inter-Rater Reliability:
Used with open-ended questions or behavioral observations.
Two or more independent observers rate responses or observed behaviors.
Similar ratings indicate relatively objective assessment.
Same procedure used for open-ended questions.
Validity
Definition: Extent to which a test measures what it is intended to measure.
Criterion Validity:
Examine whether test scores relate to other variables (biological or behavioral data) associated with the trait.
Example: Correlating aggression test scores with testosterone levels or playground hitting incidents.
Convergent Validity:
Examine whether test results correlate positively with tests measuring similar traits.
Example: Correlating extraversion test scores with assertiveness test scores.
Discriminant Validity:
Ensure that the test is not measuring something else by mistake.
Example: Ensuring an extraversion test is not also measuring verbal skill among schoolchildren.
Administer both the extraversion test and a test of verbal skill and ensure that the scores of the two tests do not correlate very highly.
Other Factors to Consider
Social Desirability:
Minimize by collecting data anonymously.
Use a lie scale (or social desirability scale) to measure the likelihood that the participant is being dishonest in answering questions.
Marlow-Crowne Social Desirability Scale is a common scale used for this purpose.
Omit data from participants scoring above a certain cutoff on the scale.
Cultural Bias:
People with different cultural backgrounds may interpret words or phrases differently.
Cultural variables can also cause response biases causing errors.
Acquiescence Bias: A tendency to agree (or respond "yes") to most questions.
The Person-Situation Debate
Debate: Which is more important in predicting behavior: personality or the situation?
Fundamental Attribution Error: Overestimating the influence of personality and underestimating the influence of the situation.
Walter Mischel (1968): Questioned the assumption that personality traits are good predictors of behavior.
Concluded that the correlation between personality and behavior was about 0.30 (low).
Situationism: Emphasizes the power of the situation to predict behavior.
Revised Correlation: Later researchers revised correlation to 0.40, still considered low.
.40 correlation means that 16% of our behavior is caused by our personality. (.40^2=.16)
Arguments for Personality Importance:
Situational variables often fail to predict behavior better.
Low personality-behavior correlations don't necessarily imply situational variables are more powerful.
Personality is a powerful predictor of behavior across situations.
People choose their situations based on personality.
Person-Situation Debate: The debate between situationists and personality psychologists.
Interactionism
Perspective: Personality traits and situations interact to influence behavior (Endler & Parker, 1992).
Assumptions:
Reality is complicated.
Behavior is the result of an interaction between the person's personality and the situation.
Both variables influence how powerful the other is as a predictor of behavior.
Self-Consciousness and Independence:
For those not very self-conscious or very independent, personality is more important.
For those more self-conscious and less independent, the situation may be more important.
Strong vs. Weak Situations:
Strong Situations: Very powerful in predicting behavior, little freedom to express personality.
Weak Situations: Personality is a strong predictor of behavior, freedom to do what one likes.
Research: Examines personality and places individuals in particular situations to see how they react.
Temperament
Definition: Genetically based, inborn aspects of personality.
Focus: Emphasizes "nature" over "nurture."
Historical Context: Ancient Greeks had a theory based on fluids (humors) leading to four types:
Sanguine: Cheerful, optimistic, abundant blood (sanguis).
Choleric: Quick-tempered, aggressive, yellow bile.
Phlegmatic: Slow, lazy, dull, phlegm.
Melancholy: Sad, pessimistic, black bile.
Dimensions: Temperature and humidity
Sanguine people are warm and wet.
Choleric people are warm and dry.
Phlegmatic people are cool and wet.
Melancholy people are cool and dry.
Pavlov used the humors to describe his dogs' personalities.
Pavlov's Dimensions
Arousal (Excitation): Overall level of arousal available in the brain.
Inhibition: Ability of the brain to change its level of arousal.
Sanguine:Lots of arousal, but good inhibition
Choleric: Lots of arousal, but poor inhibition
Phlegmatic: Not much arousal, plus good inhibition
Melancholy: Not much arousal, plus poor inhibition
Hans Eysenck
Biography:
Born in Germany in 1916.
Fled Nazis and obtained Ph.D. in Psychology from the University of London (1940).
Served as a psychologist during World War II.
Taught at the University of London and directed the psychology department of the Institute of Psychiatry
Retired in 1983 and continued to write.
Theory:
Based on physiology and genetics.
Considers personality differences as growing out of genetic inheritance (temperament).
Uses factor analysis to extract dimensions from data.
Eysenck's Dimensions:
Neuroticism: Ranges from calm to nervous
Extraversion-Introversion: Shy, quiet people versus outgoing people.
Inspired by the four temperaments of the ancient Greeks
Choleric: Extraverted and emotionally unstable
Sanguine: Extraverted and emotionally stable
Melancholic: Introverted and emotionally unstable
Phlegmatic: Introverted and emotionally stable
Neuroticism
Ranges from calm to nervousness.
Nervous people tend to suffer more from neuroses.
Genetically-based, physiologically-supported dimension of personality.
Sympathetic Nervous System: Sympathetic hyperactivity makes people prime for neurotic disorders.
Eysenck uses the example of positive feedback of a microphone to explain how mild fear can become a panic attack.
Extraversion-Introversion
Balance of inhibition and excitation (Pavlov's ideas).
Ascending Reticular Activating System (ARAS)
Extravert: Good inhibition, brain inhibits itself, becomes "numb" to trauma.
Introvert: Poor inhibition, brain doesn’t protect them fast enough, highly alert and learn well from trauma.
Violent criminals tend to be non-neuroticistic extraverts.
Interaction of Dimensions
Interactions may mean physiological problems to a person.
Phobias and obsessive-compulsive disorder tend to be quite introverted whereas People with conversion disorders tend to be more extraverted
Psychoticism
Began to study mental institutions to further expand on his theories.
Qualities include recklessness, disregard for common sense, and inappropriate emotional expression.
Discussion
Hans Eysenck was an iconoclast who was vigourous in criticizing psychotherapy
Did not believe in academic psychology
Introversion-Extraversion, Arousal, and Performance
Yerkes-Dodson Law (Optimal Arousal Theory): Performance is best at medium arousal levels.
Too low: not alert and focused.
Too high: too anxious to focus well.
Complex vs. Simple Tasks: Optimal arousal level is lower for complex tasks than for simple tasks.
Complex Tasks: Require conscious effort to focus on multiple things (e.g., learning to drive).
Simple Tasks: Well-practiced, don't require conscious effort (e.g., driving after experience).
Arousal Levels and Time of Day:
Introverted people raise their arousal levels more rapidly in the morning, reach their peak earlier, and lower them more rapidly in the afternoon and evening.
Introverts have higher arousal levels than extraverts throughout most of the day.
Extraverts may have higher arousal levels if both stay up very late.
Implications:
Introverted people tend to do well at simple tasks throughout most of the day.
Extraverted people may do better on complex tasks in the morning and late in the evening.
Extroverted people may do well at simple tasks in the middle of the day and early evening.
Jeffrey Gray's BIS/BAS Theory
Background: Interested in Eysenck's theories; developed his own.
Two Systems:
Behavioral Approach System (BAS):
Also called Behavioral Activation System or Behavioral Facilitation System.
The "GO" system; sensitive to potential rewards.
Related to motivations to seek out positive experiences.
Drives to experience positive emotion (approach motivation).
Related to Impulsivity.
Parts of the brain most highly related to the functioning of the BAS: the septal area and the lateral hypothalamus
People with higher levels of dopamine in their synapses have higher levels of impulsivity.
Recent research also suggests that extraversion is related to higher levels of dopamine.
Behavioral Inhibition System (BIS):
The "STOP" system; sensitive to signs of potential punishment, unfamiliar stimuli, and fear-inducing stimuli.
Motivates us to stop doing things that may lead to punishment.
Causes negative arousal and high alert.
Drives us to avoid negative emotion (avoidance motivation).
Related to Anxiety.
The septo-hippocampus is the part of the brain most highly associated with the functioning of the BIS.
People with high levels of anxiety seem to have higher levels of neuropeptide called norepinephrine
Relationship with Eysenck's Theory
Gray claims that his theory of impulsivity and anxiety accounts for all the individual differences in Eysenck's theory.
Being emotionally unstable and extraverted means higher impulsivity.
Being emotionally unstable and introverted means higher anxiety.
Being high in impulsivity and low in anxiety is equivalent to being high in extraversion.
Relationship with Psychological Disorders
Anxiety disorders may be related to an unusually active BIS. Depression may be associated with a combination of an extremely active BIS and an extremely underactive BAS.
Anti-social personality disorders may be related to an overly active BAS and an extremely inactive BIS.
Due to it's simplicity, Gray's work has received much attention.
Limitations: largely based on animal research
BIS(Behavioral Inhibition System)
BAS(Behavioral Activation System)Third System
Fight-Flight System - Relates to our experiences of extreme fear.
More active this system is, the more we tend to be either withdrawn or aggressive.
This system is highly associated with a brain structure known as the amygdala.
Other Biological Research
Richard Davidson (1992) suggested that approach motivations and positive feelings are highly related to activity in the left side of the frontal lobe of the cerebrum.
Research by Davidson suggests that activity in the right side of the frontal lobe is associated with feelings of anxiety, fear or disgust.
Robert Cloninger (2000) suggests that there may be three personality traits related to these two types of motivations.
Novelty seeking is one that may be related to motivations but also higher levels of dopamine
The other personality trait related to approach motivation is reward dependence.
Related to avoidance motivation is harm avoidance
The Neuron
Mental life involves activities of the nervous system, especially the brain.
Nervous system is composed of billions of nerve cells or neurons (estimated 100 billion).
Soma (Cell Body):Contains the nucleus and genetic material (chromosomes).
Dendrites: Receive chemical messages from other neurons.
Axon: Transmits electro-chemical signal to other neurons (can be long).
Myelin Sheath: Fatty cells that insulate longer axons.
Axon Ending (Bouton, Synaptic Knob, Axon Foot): Converts electro-chemical signal into a chemical message.
The Synapse
Tiny gap between the axon ending and the dendrite of the next neuron.
For every neuron, there are between 1000 and 10,000 synapses.
The Action Potential
Chemicals change the balance of ions between inside and outside of the cell membrane.
When this change reaches a threshold level, it initiates the action potential (rapidly moving exchange of ions).
Ion Channels: Miniscule mechanisms on the axon surface that allow ions to enter and change the electrical balance.
The Synapse (cont)
When the action potential reaches the axon ending, chemicals called vesicles release their contents into the synaptic gap.
These chemicals are called neurotransmitters.
They sail across the gap to the next neuron, where they find special places on the cell membrane of the next neuron called receptor sites.
The neurotransmitter acts like a little key, and the receptor site like a little lock.
They open a passage way for ions, which then change the balance of ions on the outside and the inside of the next neuron.
Types of Neurons
Sensory: Sensitive to non-neural stimuli (e.g., pressure, temperature, pain, tastes, smells, sound, light).
Motor: Stimulate muscle cells throughout the body (heart, diaphragm, intestines, bladder, glands).
Interneurons: Provide connections between sensory and motor neurons, as well as between themselves (central nervous system).
Ganglion or Nucleus: A clump of neuron cell bodies.
Nerve: A fiber made up of many axons.
White Matter: Areas in the brain and spinal cord that are mostly axons.
Gray Matter: Areas that include large numbers of cell bodies.
Neurotransmitters
Chemicals that transmit signals from one neuron to the next across synapses.
Acetylcholine
First neurotransmitter to be discovered (Otto Loewi, 1921).
Responsible for muscle stimulation, sensory neurons, autonomic nervous system, and REM sleep.
Plant poisons curare and hemlock cause paralysis by blocking receptor sites of muscle cells.
Botulin prevents vesicles from releasing acetylcholine, causing paralysis.
Link between acetylcholine and Alzheimer's disease
Norepinephrine
Discovered by Ulf von Euler (1946).
Associated with bringing the nervous system into "high alert."
Increases heart rate and blood pressure.
Important for forming memories.
Stress depletes adrenalin and exercise is increased by it.
Amphetamines work by causing the release of norepinephrine.
Dopamine
Discovered in the 1950s Arvid Carlsson.
Inhibitory neurotransmitter.
Associated with reward mechanisms in the brain.
Cocaine, opium, heroin, alcohol, and nicotine increase dopamine levels.
Excessive amounts in frontal lobes may cause schizophrenia; blocked by drugs to help schizophrenics.
Too little dopamine in motor areas causes Parkinson's disease.
L-dopa can eleviate some of the symptoms of Parkinson's.
Low dopamine may relate to the unsociability of schizophrenics, but also to social anxiety.
Cocaine inhibits the re-uptake of dopamine.
GABA
Discovered by Eugene Roberts and J. Awapara (1950).
Inhibitory neurotransmitter.
Acts like a brake to the excitatory neurotransmitters that lead to anxiety.
People with too little GABA tend to suffer from anxiety disorders; Valium enhances the effects.
Lack of GABA in certain parts of the brain results in epilepsy.
Glutamate
Excitatory relative of GABA.
It is the most common neurotransmitter in the central nervous system.
Important in regards to memory.
Glutamate is actually toxic to neurons, and an excess will kill them
ALS, more commonly known as Lou Gehrig's disease, results from excessive glutamate production.
Serotonin
Inhibitory neurotransmitter involved in emotion and mood.
Too little serotonin can cause depression and is a derivative of tryptophan.
Can lead to problems with anger control, obsessive-compulsive disorder, and suicide
It is released by warm milk.
Too little can lead to an increased appetite for carbohydrates and trouble sleeping.
Used in hallucingens such as LSD, mescaline, psilocybin, and ecstasy work by attaching to serotonin receptor sites and thereby blocking transmissions in perceptual pathways.
Endorphin
Discovered by Solomon Snyder and Candace Pert of Johns Hopkins (1973).
Short for "endogenous morphine."
Structurally similar to opioids and has similar functions: inhibitory, pain reduction, and pleasure.
The neurotransmitter that allows bears and other animals to hibernate.
Human Evolution
Humans evolved from earlier forms, but we are not descended from apes.
Common ancestor to humans and apes lived over five million years ago.
Australopithecus: Evolved about three million years ago, walked on two legs, used tools, hunted; brain between 400-500 cc.
Australopithecus split into A. boisei and A. robustus; a line that became extinct.
A different line into Homo habilis, about two million years ago. H. habilis stood about 5 feet tall, weighed about 100 lbs, and had a brain from 500 to 800 cc.
Homo Erectus: 1 million years ago, the first fire user with a brain from 900 to 1200 cc
Homo Sapiens:enters the scene, back in Africa, with a 1200 cc brain around 300,000 years ago.
Homo neanderthalensis : a cousin of ours, not an ancestor to to came 150,000 to 30,000 years ago
Humans: We seem to have invented art in the form of cave paintings and female statuettes and has a brain about 1250 cc
Different "races" are not sub-species; genetic differences are small.
Qualities of Homo
Being upright.
Excellent Vocalizers.
Large Brain for it's time.
Sociobiology
Social behaviors are affected by evolution (E. O. Wilson).
Sociobiology found more and more supporters among biologists, psychologists, and even anthropologists. Only sociology has remained relatively unaffected.
The three-spined stickleback shows a series of instincts.
Certain patterns of behavior are shown on male and female such as promoting oneself and nurturing.
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Evolution pt. 2
All animals tend to over-reproduce, yet there are stable generations.
Natural selection: nature encourages the propagation of positive traits and discourages negative ones such as survival and reproduction.
David Barash: Why is sugar sweet