1 psychology 305a: personality psychology january 14 lecture 3

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Psychology 305A: Personality Psychology

January 14

Lecture 3

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Announcement

The tutorials for the Peer Mentor Program will be held on the following dates:

January 21, 3:30-4:30February 12, 3:00-4:00March 4, 3:30-4:30March 24, 4:00-5:00April 7, 4:00-5:00

Location to be announced.

A little R&R ….(Review and Reflect)

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Personality Assessment and the Trait Perspective

1. How are personality variables measured?

2. How do researchers establish the reliability and validity of a personality measure?

3. What are traits?

4. Has a comprehensive taxonomy of personality traits been developed?

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By the end of today’s class, you should be able to:

3. distinguish between face, predictive, convergent, and discriminant validity.

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2. distinguish between internal consistency, inter-rater reliability, and test-retest reliability.

1. review personality measurement techniques.

4. describe Eysenck’s personality taxonomy.

How are personality variables measured? (continued)

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Participants complete the statement “I am” 20 times.

Researchers count the number of statements that refer to a given personality characteristic.

Unstructured Self-Report: The Twenty-Statements Test

I am _______________I am _______________I am _______________I am _______________

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True/false items: I like loud and crowded parties ………… T/FI enjoy trying new foods …………………. T/F

Adjective checklists: adventurous

conservative

Structured Self-Report: True/False Items and Adjective Checklists

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Using the scale below, please indicate how much you disagree or agree with the following statements. Circle the appropriate number to the right of each statement.

1 2 3 4 5 Strongly Neutral Strongly disagree agree

1. I feel that I’m a person of worth, at least on an equal basis with others …………………………….. 1 22. I feel that I have a number of good qualities …….. 1 23. All in all, I am inclined to feel that I am a failure …. 1 24. I am able to do things as well as most people …… 1 2

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Structured Self-Report: Rosenberg’s Self-Esteem Scale

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• Rosenberg’s Self-Esteem Scale:

Measures global feelings of self-worth (“trait” self-esteem).

Mean score for university undergraduates: 38 (maximum possible score = 50), SD = 6.2.

Females tend to score slightly lower than males, largest sex difference in adolescence (15-18).

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How do researchers establish the reliability and validity of a personality measure?

• In order to accurately assess a personality variable, the measure that is used must be reliable and valid.

The consistency with which a measure assesses a construct across repeated measurements.

• Reliability

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Three forms:

1. Internal consistency:

• Relevant for multi-item measures (e.g., questionnaires).

• The degree to which the items in the measure produce similar responses (i.e., tap the same construct).

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Using the scale below, please indicate how much you disagree or agree with the following statements. Circle the appropriate number to the right of each statement.

1 2 3 4 5 Strongly Neutral Strongly disagree agree

1. I feel that I’m a person of worth, at least on an equal basis with others …………………………….. 1 22. I feel that I have a number of good qualities …….. 1 23. All in all, I am inclined to feel that I am a failure …. 1 24. I am able to do things as well as most people …… 1 2

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Structured Self-Report: Rosenberg’s Self-Esteem Scale

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2. Inter-rater reliability:

• Relevant when observer ratings are obtained from two or more observers.

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• The degree to which the scores provided by different observers are consistent with one another (i.e., there

is consensus among observers).

• Involves calculating the correlation between the scores provided by different observers.

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3. Test-retest reliability:

• Relevant for all types of measures.

• The degree to which participants’ scores on the measure at time 1 are consistent with their scores on

the measure at time 2.

• Involves calculating the correlation between participants’ scores on successive test administrations

(i.e., their scores at time 1 and scores at time 2).

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The degree to which a measure assesses the construct it is intended to measure.

• Validity (or construct validity)

A measure that is reliable may or may not be valid; a valid measure must be reliable.

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Four forms:

1. Face validity:

• The degree to which a measure appears to tap the construct under study.

• E.g., Rosenberg’s Self-Esteem Scale.All in all, I am inclined to feel that I am a failureOn the whole, I am satisfied with myself

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2. Criterion validity (or predictive validity):

• The degree to which a measure correlates with a behaviour that is theoretically related to the

construct under study.

• E.g., A self-esteem measure should be correlated with: alcohol and drug use persistence in the face of failure number of sexual partners (i.e., sexual promiscuity)

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3. Convergent validity:

• The degree to which a measure correlates with measures that assess conceptually-related constructs (i.e., constructs that are theoretically related to the construct of interest).

• E.g., A self-esteem measure should be correlated with measures of: depression. neuroticism. positive affectivity.

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4. Discriminant validity:

• The degree to which a measure does not correlate with measures that assess conceptually unrelated

constructs (i.e., constructs that are not theoretically related to the construct of interest).

• E.g., A self-esteem should not be correlated with measures of:

agreeableness. need for cognition. political attitudes (i.e., liberal vs. conservative).

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• Often, convergent and discriminant validity are examined simultaneously:

Dep Neur PosAff Agree NCogn Polatt

SE -.68 -.57 .63 .06 .09 -.02

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• According to the trait perspective, personality is best described as a constellation of traits (e.g., anxious, conscientious, outgoing).

Example: Peter is jealous. “Jealous” describes Peter’s behaviour.

• Traits are viewed as descriptive summaries of behaviour.

What are traits?

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Has a comprehensive taxonomy of personality traits been developed?

• Taxonomy: A classification system (e.g., Periodic Table of Elements).

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• Over the past century, dozens of taxonomies have been proposed for personality traits.

• Examples:

1. Eysenck’s personality taxonomy: PEN

Developed on the basis of pre-existing theory: Body Humors Theory (Hippocrates, Galen).

Proposes three personality dimensions: Extraversion, neuroticism, and psychoticism.

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Personality Types Derived from Eysenck’s Taxonomy

Low Neuroticism (Emotionally Stable)

High NeuroticismEmotionally Unstable

Introvert

PassiveCarefulThoughtful APeacefulControlledReliable

QuietPessimisticUnsociable BSoberRigidMoody

Extravert

SociableOutgoingTalkative CResponsiveEasygoingLively

ActiveOptimisticImpulsive DChangeableExcitableAggressive

A = Phlegmatic; B = Melancholic; C = Sanguine; D = Choleric

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By the end of today’s class, you should be able to:

3. distinguish between face, predictive, convergent, and discriminant validity.

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2. distinguish between internal consistency, inter-rater reliability, and test-retest reliability.

1. review personality measurement techniques.

4. describe Eysenck’s personality taxonomy.