1. Trait Approaches Trait Approaches

2. Studying Personality Traits What is the best way to describe personality? How can we identify which traits are the most important from among the thousands of ways in which individuals differ? How can we formulate a comprehensive taxonomy of traits? How can we measure traits?

3. What are traits? Traits = Broad dispositions to act in specific ways Disposition = tendency (e.g., repressors tend to avoid threatening experiences) Broad = abstraction (not specific instance; adjectives (helpful) rather than verbs (help))

4. What are traits? Traits are: 1. Dimensional (ordering of people) not categorical 2. Hypothetical (not observable) 3. Causal (internal) or Descriptive (summaries)

5. What is a Trait? Internal causal properties  Internal: individuals carry their desires, needs, and wants from one situation to the next  Causal: desires and needs explain the behavior of the individuals who possess them George is jealous because he is insecure

6. What is a Trait? Purely Descriptive Summaries  Make no assumptions about internality, nor is causality assumed  Trait describes expressed behavior George glares at other men who talk to his girlfriend. He must be jealous.

7. What are traits? Traits are (continued): 4. Organized in a system 5. Consistent over settings and time

8. Trait Organization Comprehensive trait taxonomies assume traits exist at varying levels of abstraction and are organized hierarchically Major taxonomies –Eysenck –Cattell –Five factor model

9. Taxonomies of Personality Eysenck’s Hierarchical Model  Extraversion-Intraversion  Neuroticim-Emotional Stability  Psychoticism

10. Hierarchy – Eysenck’s Extraversion Extraversion Sociability HR1 SR HR2 Impulsiveness HR1 SR Activity Liveliness Excitability

11. What are traits? Traits/behaviors are assumed to be consistent over settings and stable over time - Types of consistency Absolute Relative Situationally Relative

12. Types of Consistency - Absolute

13. Types of Consistency - Relative

14. Types of Consistency - Situationally Relative

15. Studying Traits Nomothetic – determine/use set of common traits. Analytic; allows for comparison Idiographic – determine each individual’s unique traits

16. Measuring Traits Objective Tests Traits are abstractions based on common features (e.g., extraversion; desks) Traits are hypothetical – can not measure directly - Translate trait into something measurable

17. Measuring Traits Objective Tests Many measures of same trait Examples All have error – variance not due to trait Trait Measure

18. Measuring Traits Objective Tests Different types of measures have different sources of error Trait measurement involves an epistemic inference: can not know with absolute certainty measure is tapping intended trait (due to its hypothetical nature)

19. Psychometrics Evaluating Objective Measure of Personality Traits

20. Measuring Traits Objective Tests Many measures of same trait Examples All have error – variance not due to trait Trait Measure

21. Measuring Traits Objective Tests Different types of measures have different sources of error Trait measurement involves an epistemic inference: can not know with absolute certainty measure is tapping intended trait (due to its hypothetical nature)

22. Reliability Does measure yield consistent scores over time, observers, and items –Estimates error component –Three types: Temporal Inter-rater Internal Consistency

23. Temporal Reliability Does measure yield consistent scores over time Assess: Test-Retest reliability coefficient –Measure trait at Time 1 and Time 1(less than 6 months) and compute correlation

24. Inter-rater reliability Does measure yield consistent scores over observers Required for measures with subjective component (e.g., projective, behavior) Assess with agreement rate Low agreement rate indicates high error (idiosyncratic observer perceptions)

25. Internal Consistency Consistency over items Increasing number of items increases temporal reliability; However, items need to measure same trait Assess: Split-half reliability coefficient –Correlate scores of two halves (randomly selected)

26. Internal Consistency continued Average item-total correlation –Average correlation of each item with total Example – Extroversion Item:Person 1 Person 2 Person 3 # friends30 5 20 # phone calls 35 2 4 # football games 6 5 10 # parties15 1 10 Total86 13 44

27. Validity Does measure tap intended trait? Reliability necessary but not sufficient for validity Trait measure Any trait Measure

28. Validity Types Construct Validity Theoretical; what is measure assessing? How does it relate to other constructs? Criterion Validity Practical; does measure serve intended purpose?

29. Construct Validity Convergent. Measure should correlate with other measures of same/similar construct. –Correlate using different assessment types E.g., Extroversion with peer reports, behavior Discriminant. Measure should not correlate with other measures of different constructs E.g., Extroversion with social anxiety, social desirability

30. Criterion Validity Predictive –Does measure predict future behavior related to measured trait? E.g., GRE, SAT, job placement Concurrent –Does measure differentiate between groups known to differ? E.g., Depression measure should discriminate between (diagnosed) depressed and controls

31. Strategies for Developing Trait Measures Theoretical Approach Group Contrast Approach Factor Analytic (Lexical + Statistical)

32. Measurement Strategies Theoretical Approach Starts with a theory which then determines which variables are important Freudian The Oral Personality The Anal Personality TheoryWould measure

33. Measurement Strategies Theoretical Approach Outline of steps 1. Starting point: Theory (e.g., MBTI; Jung) 2.Generate many items (expert opinion), face validity 3.Administer items to sample

34. Measurement Strategies Theoretical Approach Outline of steps 4. Examine internal consistency; discard poor items 5. Evaluate psychometric properties Weaknesses:

35. Measurement Strategies Group Contrast Approach Outline of steps 1 Starting point is a practical concern (e.g. psychopathology identification; MMPI) 2 Recruit respondents differing on dimensions 3 Develop items (little face validity)

36. Measurement Strategies Group Contrast Approach Outline of steps (continued) 4 Retain items that differentiate significantly between groups (concurrent validity) “I tease animals” Weaknesses

37. Measurement Strategies Factor Analytic (Lexical + Statistical) Outline of steps: 1 Starting point: lexicon (dictionary) Natural language assumption: All important individual differences have become encoded within the natural language 2 Reduce number of traits via semantic analysis

38. Measurement Strategies Factor Analytic Outline of steps (continued): 3 Factor analyze ratings; trait covariations define higher order factors Cattell and 16PF Five Factor Model

39. Correlation Matrix EngFine Arts Hist.Phil.Calc.ChemPhys Eng1.70.80.30.40 F. Art1.80.70.40.50 Hist1.90.30.40 Phil1.50.30.50 Calc1.80.90 Chem1.80 Phys 1

40. Hypothetical Factor Loadings Eng.Fine Arts Hist.Phil.Calc.ChemPhys. Factor 1.7.6.7.8-.1-.2.05 Factor 2.1.15.2.3.7.65.82 Factor 3.2-.1.15.18-.2.05.2

41. Hypothetical Factor Loadings Detach ed CoolWarm Hearted Easy Going Self Assur ed Confid ent Depres sed Worry ing Factor 1.9.85-.75-.65.02 -.1-.2 Factor 2.1.2.01.02.9.8-.7-.6 Factor 3 -.070.2-.15.1-.05.3.45

43. 16pf Psychometric Properties Test-Retest Reliability (6 days); n = 146 A B C E F G H I.81 -.76.80.79.81.83.77 L M N O Q1 Q2 Q3 Q4.75.70.61.79.73.75.62.81

44. 16pf Psychometric Properties Split-half Reliability (n = 218) A B C E F G H I.56 -.43.61.64.55.78.77 L M N O Q1 Q2 Q3 Q4.25.10.21.48.06.48.40.70

45. 16pf Psychometric Properties Factor Loadings A B C E F G H I.77 -.62.71.66.75.63.71 L M N O Q1 Q2 Q3 Q4.63.58.59.75.66.62.58.75

46. 16pf Psychometric Properties Criterion Validity – Predictive/Concurrent Moderately high C maintain better group morale High M have significantly more auto accidents High H prefer living in city center and travel

47. 16pf Psychometric Properties Summary Test-retest moderately low; relatively few items Internal consistency (split-half) moderately low –Few items and emphasis on factor breadth (relatively high factor loadings)

48. Taxonomies of Personality Criticisms of Factor Analytic/Natural Language 1. Implicit personality theories 2. Method subjectivity; number/names of factors 3. Validity of Natural Language assumption 4. Validity of lay raters 5. Lack of correspondence between taxonomies

49. Taxonomies of Personality Five Factor Model  Surgency or Extraversion  Agreeableness  Conscientiousness  Emotional Stability  Openness-Intellect

51. Taxonomies of Personality Circumplex Taxonomies of Personality  Leary Circumplex  Wiggins Circumplex

53. Critique of Trait Approach Self-report Measures –Social Desirability Evidence (e.g., voting) Handle –Measure –Reduce response time –Equate forced choice items

54. Critique of Trait Approach Walter Mischel – Traits don’t predict behavior –Trait-behavior; r <.3 –Behavior-behavior; r <.3 (see Hartshorn & May) –People are inconsistent and traits don’t predict behaviors

55. Hartshorn & May Behavioral Manifestations of Honesty CopyingPeepingAthletic Copying 1.0 Peeping.28 1.0 Athletic.20.06 1.0 Lying.31.15.0 Mean r =.21

56. Mischel’s critique continued Why continued use of traits? –Fundamental Attribution error –Traits illusory E.g.,

57. Responses to Mischel Are traits an illusion? Evidence against (unacquainted raters) Measurement Issue Aggregation – multiple measures – more reliable (e.g., class attendance) Interactionism

58. Differential effects of traits over settings For example: Anxiety Trait Anxiety: Situation:HighLow Threat 10 4 No threat 4 3

59. Theoretical Interactionism Snyder & Ickes Moderator Variable Approach –When do traits predict behaviors? (i.e., what variables moderate trait-behavior relationship?) Moderator Variables: Situation Strong vs. Weak

60. Moderators cont. Behaviors Prototypical (best exemplars) Traits Central Specific People Self monitoring Private Self consciousness