Lecture 17: Personality Theories
last updated 3/2/2004

I. Introduction to Personality

A. Definition: Distinctive and relatively enduring ways of thinking, feeling, and acting that characterize person's responses to life situations.

B. Let's begin with some personality tests (class demo)

C. Different psychological theories of personality

1. Trait theory

2. Psychodynamic theory

3. Cognitive-behavioral theory

4. Humanistic theorty

5. Sociocultural theory

II. Trait Theories

A.  Traits vs. States

1. Traits are stable characteristics, displayed in most situations

2. States are temporary characteristics (e.g., a state of confusion)

3. English language contains over 18,000 different "personality" words


B. Historical Formulations (dates approximate)

1. Humourism (Hippocrates, Galen, 400BC-1600AD)

2. Somatotypes (William Sheldon, 1940s)

a. Definition – personality classification according to body shape: Sheldon's originals | contemporary version | read more

1. Endomorph: heavy and fat, with a soft body and poorly developed muscles (example)

a. sociable
b. relaxed
c. affectionate

2. Mesomorph: husky, with a hard and muscular body, athletic type (example)

a. energetic
b. competetive
c. aggressive

3. Ectomorph: tall and slim, lightly built, with flat chest and poorly muscled limbs (example)

a. inhibited
b. apprehensive
c. self-conscious

b. Research findings

1. Some early support: Delinquent boys more likely to be mesomorphs (Glueck & Glueck, 1956)

2. Preponderence of evidence — No significant relationship between body type and personality

3. Many people simply do not fit into the neatly packaged category.

4. Three categories ignore the rich diversity and complexity of human characteristics

C. Contemporary Developments

1.  Hans Eysenck (1958)

a. two main dimensions

1. introvert vs. extrovert (cartoon)
2. emotionally stable vs. emotionally unstable

b. contained many personality sub-types

c. some evidence of cross-cultural validity

2.  Gordon Allport (1961)

a.  common traits (shared by culture) vs. individual traits

b.  cardinal, central, and secondary traits

3.  Raymond Cattell (1965)

a.  used factor analysis to group 4500 adjectives

1. surface traits (visible personality)
2. source traits (clusters of surface traits)

b.  Cattell's 16 PF (validity: writers and artists similar, both different from pilots)

4.  The "Big Five"  (Go Penn!!, but not into the OCEAN)

a.  extroversion

1. sociable vs retiring
2. fun-loving vs sober
3. affectionate vs reserved

b.  agreeableness

1. soft-hearted vs ruthless
2. trusting vs suspicious
3. helpful vs uncooperative

c.  conscientiousness

1. Organized vs disorganized
2. careful vs careless
3. disciplined vs impulsive

d.  neuroticism (emotional stability)

1. calm vs anxious
2. secure vs insecure
3. self-satisfied vs self-pitying

e.  openness to experience

1. imaginative vs practical
2. preference for variety vs preference for routine
3. independent vs conforming

D. Trait Assessment

1. Professional tests

a. Minnesota Multiphasic Personality Inventory (MMPI, MMPI-2)

1. most widely used clinical personality tests

2. original MMPI developed in the 1940’s

a. 504 T-F items
b. normed on white, married men with 8th grade education

3. modified in 1989 (MMPI-2) with new norms

a. 567 T-F items (takes 60-90 minutes to complete)
b. repeat items, 2 new scales
c. items chosen using empirical data from over 1000 statements

                    1. "normals" = 724 persons from Minnesota census
                    2. "clinical group" = from Minnesota hospitals

d. sample questions

4. scoring: 13 scales (full descriptions)

a. 10 clinical: (e.g., Depression, Hysteria, Mania, Paranoia, etc.)
b. several validity scales
           1. fake-good (e.g., I smile at everyone I meet)
           2. fake-bad
           3. exaggeration

b. California Psychological Inventory (CPI), focuses on normal personality

2. Self-administered tests

a. Big 5 Personality Test

b. Keirsey Personality Sorter (Keirsey Profiles)

c. Some fun tests (no demonstrated validity)

E. Strengths and weaknesses of trait theory/assessment

1. Weaknesses

a. Descriptive only (provides no information about origin)

b. Vulnerable to faking

c. Limited by person's knowledge of self

d. Undervalues influence of situations on behavior

1. behavioral inconsistencies found across different situations (sometimes r<.30))
2. inconsistency includes “traits” such as honesty, aggression, dependency, rigidity
3. personalities seem stable because people tend to frequent same settings repeatedly

2. Strengths

a. Strong face validity

b. Can be group or even self-admistered

c. Recent measures have high reliability and decent predictive validity (about .30)

d. Consistency actually not all that low

1. trait consistency over time is good (.6 to .9)
2. greater consistency across situations (.50) when traits, not behaviors, are judged (e.g., aggression vs. hitting)
3. greater consistency across situations with multiple observations (.60)

3. Conclusions

a. Strong evidence for a trait-situation interaction model
b. Strong evidence for both genetic and environmental influences on personality

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