Dispositional Approach: Assessment, Personality Change, & Research
Assessment
- Behavior reflects individual (trait) differences
- Frequent use of self-report or observational ratings
- NEO Personality Inventory
- Neuroticism
- Extraversion
- Openness to Experience
- Agreeableness
- Conscientiousness
Personality Change
- DSM-IV (clinical perspective)
- Personality trait
= enduring pattern of perceiving, relating to, and thinking about the environment and oneself that are exhibited in a wide range of social and personal contexts
- Personality disorder
= when personality traits are inflexible, maladaptive, and cause significant functional impairment or distress
Personality Change
- Assumption: Traits are relatively stable, and to some extent they are biologically or genetically based
- Implication: They will be resistant to change
- Approaches: A variety of techniques
- Psychological (e.g., behavioral/learning)
- Psychopharmacology (neurotransmitters)
- Genetic engineering? (future possibility)
Research
- Assumption: Traits are relatively stable over time
- "By the age of 30, our personality is set like plaster" (Costa & McCrae)
Research
- Issues to consider
- Magnitude of stability coefficients
- Group means can mask enormous individual change
- Change is possible (not deterministic)
Research
- Assumption: Personality traits are to some degree biologically or genetically based
- Behavioral Genetics addresses this issue
Behavioral Genetics
- Polygenic
vs. single gene
- Nature vs. Nurture (always an interaction)
- Waddington’s (1957) Movement of ball down landscape metaphor
- Relative proportion of variance
Behavioral Genetics
- Twin studies
- Monozygotic (MZ)--100% genetically identical
- Dizygotic (DZ)--50% genetic similarity
Behavioral Genetics
- Concordance rate
= degree of similarity among twin pair
- Categorical method (discrete data/groups)
- % concordant for the condition
- Correlational method (continuous data/degree)
- Average correlation coefficient for twin pairs on the trait
Behavioral Genetics
- Heritability Index
(h2) = proportion of phenotypic variance due to genetics
- Note: h2 is a sample-based estimate
- Three methods to estimate h2 for continuous data (average correlation coefficients)
Behavioral Genetics
1. MZ reared apart
2. (DZ reared apart) x 2
- e.g., (.20) x 2 = .40 = 40%
3. (MZ total - DZ total) x 2
- e.g., (.65 - .45) x 2 = .40 = 40%
Psychobiology
- Extraversion
(Eysenck)
- Extraversion is associated with differential activation of the Ascending Reticular Activating System (ARAS) in brainstem
Psychobiology
- Extraverts
have lower ARAS
- Less arousable cortexes
- Higher sensory thresholds
- Seek out external stimulation
Psychobiology
- Introverts
have higher ARAS
- Easily aroused
- Shy away from external stimulation
Psychobiology
- When exposed to the same level of stimulation, introverts become more physiologically aroused than extroverts
- Introverts
find punishment more aversive and are more likely to inhibit their behavior to avoid it
- Extraverts
are more likely to use stimulant drugs
Psychobiology
- Neuroticism
(Eysenck)
- Individuals high on neuroticism have more arousable autonomic nervous systems (ANS) and experience more negative emotions
- Increased risk of developing depression and anxiety
Psychobiology
- Gray’s Model
- Behavioral Inhibition System (BIS)
- Sensitivity to punishment
- Low serotonin is asssociated with anxiety
- Similar to Eysenck’s Neuroticism
Psychobiology
- Behavioral Activation System (BAS)
- Sensitivity to reward
- High dopamine is associated with pleasure seeking and impulsivity
- Similar to Eysenck’s Extraversion
Psychobiology
- Sensation-Seeking
(Zuckerman)
- Tendency to seek out thrilling and exciting activities, take risks, avoid boredom
- Associated with low MAO
- MAO is an enzyme that breaks down certain neurotransmitters (MAO = inhibition)
- In contrast, depression/anxiety = high MAO
Evolution
- Please read the following scenarios and circle the one you would find more upsetting:
Evolution
Scenario A
Your partner recently made friends with a co-worker of the other sex and has been spending more and more time with that person. You are sure that the two of them have not had sexual intercourse, but they seem to like each other very much. The two of them have many things in common and you suspect that they are falling in love.
Evolution
Scenario B
You discover that, while your partner was away on vacation, your partner met someone and had sexual intercourse once with that person. You are sure that your partner loves you very much and highly values your relationship together. You also realize that, even though your partner did have sexual intercourse while on vacation, it was a "one-night-stand" and your partner would never see that person again.
Evolution
- Compute frequencies for this class:
- Male students
- Scenario A = ?
- Scenario B = ?
- Female students
- Scenario A = ?
- Scenario B = ?
Evolution
- "I feel that the major, most fundamental dimensions of personality are likely to be those on which variation has had evolutionary significance, and that this evolutionary history is likely to manifest itself in strong genetic determination of individual differences along these dimensions (Allport, 1977)."
Evolution
- "Personality theories inconsistent with evolutionary theory stand little chance of being correct (David Buss, 1991)."
Evolution
- Evolutionary psychologists seek to understand aspects of human functioning in terms of their relation to evolved solutions to adaptive problems faced by the species over millions of years.
- Basic psychological mechanisms are the result of evolution by natural selection (they exist because they were adaptive to survival and reproductive success).
Evolution
1. Partner preferences (mate selection)
2. Male-female differences in causes of jealousy
Evolution
- David Buss: Mating desires of people in 37 cultures
- Found empirical evidence of universality to men’s and women’s desires
- What do you think they were?
- In a female mate, men desire…?
- In a male mate, women desire…?
Evolution
- General findings (Buss):
- Men desire women for their reproductive capacity (youth and physical attractiveness)
- Women desire men for the resources they can supply (earning capacity, ambition, industriousness)
Evolution
- According to evolution (natural selection/pass on genes), what are the different underlying motivations for mate selection?
- Men’s goal = ?
- Women’s goal = ?
- What are the implications for jealousy?
- Sexual vs. emotional infidelity
Evolution
- Wiederman & Kendall, 1999: Jealousy study in Sweden
- Method = Correlational study
- Subjects = 173 male and 203 female college students
- Procedure = subjects completed self-report questionnaires in classroom
Evolution
- Independent variables
- Subject’s sex (M/F)
- Scenario (sexual vs emotional infidelity)
- Dependent variable
- Which scenario they rated "most upsetting"
Evolution
- Results (Which most upsetting?)
- Men: Sexual = 69%; Emotional = 31%
- Women: Sexual = 31%; Emotional = 69%
- X
2 (1, N = 376) = 23.19, p < .00001.
Evolution
- Variations leading to similar findings:
- Physiological reactivity to imagined sexual vs. emotional infidelity
- Self-report ratings of hypothetical jealousy in response to rival with different body build
- Low waist-to-hip ratio
(indicator of health and reproductive status in women)
- High shoulder-to-hip ratio
(indicator of social dominance in men)
Strengths of Dispositional Approach
- Applies to general population (normal personality)
- Appreciates biological factors
- Relatively parsimonious
Limitations of Dispositional Approach
- Overemphasis on biological factors
- Simply descriptive (aggressive because…)
- Underestimates the importance of situational factors in predicting behavior
- Pays inadequate attention to personality development and change
- Limits of self-report
- Limits of factor analysis