What makes a theory good? Comprehensiveness –Bandwidth (Wide Range) –Fidelity (Very Specific) Parsimony (Ockham’s Razor) Research Relevance –Empirical Testability –Falsification must be possible

Personality Traits Is our personality defined by a limited number of basic, universal traits?

Overview What is a trait? What is the trait approach? How do traits measure personality? Famous trait theorists Criticism of the trait approach

Self-Descriptions (USA) "I am a very independent, somewhat overbearing female who is quick to speak her mind … I am sometimes stubborn, judgmental, and I have been known to forgive too easily, which makes me seem 'two faced' at times" "Easy-going, reflective, sarcastic sense of humor, loyal, caring, competitive, analytical, self-critical, compassionate" "I have a great tendency to be a perfectionist … I am a superstitious person … also, I am a completely honest person … I see myself as less of a speaker and more of a listener."

A Working Definition of Traits “Traits are many things to many people” (Wiggins, 1997) Global tendencies to think, feel, behave in a certain way Helpful in describing and comparing psychological attributes of people Related to laypeople’s views of personality

Main Assumptions Traits are stable over time Traits are stable across situations Traits are hierarchically organized Traits are dimensional - not categorical Individuals are unique in... –how high they score on each trait –patterns of traits –number of traits (for some models)

Hierarchical Organization Example: Eysenck’s Description of Extraversion

Traits vs. Types Types (e.g. body types) –categorical –each person gets assigned to one type Traits (e.g. extraversion) –dimensional –quantitative value on a scale Introverted Neutral Extraverted | | |

Normal Distribution Number of people with that value Introverted Extraverted

Histogram of Extraversion Number of people with that value Introverted Extraverted

Research Controversies Number of basic traits? Sources of traits (biological vs. learned) “Ontological” status of traits –Traits as “causes” of behavior –Traits as descriptions of behavioral tendencies Which research approach is best? Traits vs. states

Research Approaches Nomothetic –Limited number of universal traits –Research on the distribution of universal traits in the population Idiographic –Unique traits for specific individuals –Intensive study of a few individuals

Refining Trait Measurement Snyder (1974): Self-monitoring High self-monitors adapt to the current situation Low self-monitors have consistent traits Bem & Allen (1974) “On predicting some of the people some of the time” People differ in their consistency for traits Only personally relevant traits are consistent

Traits vs. States Trait Enduring disposition Stable across time and situations State Reaction tendencies, moods Dependent on the situation Spielberger (1983) State-Trait-Anxiety-Inventory

Development of Personality Tests How do we describe people?

Test Construction Rational Develop a theory about number & nature of traits Formulate questions that describe each of the traits Empirical Collect large number of items Pick the ones that differentiate between different groups of people Factor Analytic Collect large number of items Pick the ones that form well-defined clusters

Important Trait Theorists Allport (lexical studies) Eysenck (biological basis of traits) Goldberg, Costa, McCrae (“Big Five”)

Allport ( ) Lexical studies (with Odbert, 1936) Extracted 17, 953 person-descriptive terms Traits as biological cause of behavioral trends in humans Idiographic approach

Eysenck ( ) Emphasis on objective scientific methods Hierarchical view of personality traits Three dimensions of personality: –Introversion –Neuroticism –Psychoticism Traits are based on reactivity of the nervous system (introverts more reactive)

True or False? Compared to Introverts, Extraverts … have more positive emotions on average are physiologically more responsive to the same noise have earlier and more varied sexual contact get drunk more easily seek novelty and social interaction study in coffeehouses, not libraries have more dates have fewer but more intense friendships find it harder to study with music on report that their lives are more meaningful

Goldberg, Costa, McCrae “Big Five” Model O penness to experience C onscientiousness E xtraversion A greeableness N euroticism Currently the most researched model

Big Five Lexical approach & factor analysis Strong links to biology assumed Intercultural comparisons find similar factorial structure Research findings: –O: positive outlook –C: planful problem solving –E: seeking social support –A: avoiding confrontation –N: avoidant coping