2/10/20091Theoretical and Measurement Issues in Trait PsychologyChapter 4Theoretical Issues Meaningful Differences Between Individuals  Consistency Over Time Consistency Across Situations Person-Situation Interaction Aggregation2/10/20092Meaningful Differences Between Individuals There are meaningful differences between individuals (traits psychology is also called differential psychology) People differ in amounts of traits, and differences can be accurately measured According to trait psychologists, every personality is the product of a combination of a few basic, primary traitsConsistency Over Time Research indicates consistency over time for broad traits Although consistent over time, how a trait is manifested in behavior might change over time How can there be consistency in a trait if it is known to change with age (e.g., impulsivity)? Focus on the rank order differences between people2/10/20093Consistency Across Situations Trait psychologists traditionally assumed cross-situation consistency If situations mainly control how people behave, then the existence or relevance of traits questionable Hartshorne and May (1928): Low cross-situation consistency is in honesty, helpfulness, self-controlConsistency Across Situations Mischel (1968): Personality psychologists should abandon their efforts to explain behavior with traits, focusing instead on situations Situationism: If behavior varies across situations, then situational differences and not personality traits determine behavior2/10/20094Consistency Across Situations Mischel’s (1968) critique encouraged debate in personality psychology about the importance of traits compared to situations in causing behavior Both sides tempered views: Trait psychologists acknowledged the importance of situation, and situationists acknowledged the importance of traitsConsistency Across Situations Debate led to two lasting changes: Focus on Person-Situation Interaction and Practice of Aggregation2/10/20095Person-Situation Interaction Two possible explanations for behavior: Behavior is a function of personality traits Behavior is a function of situationPerson-Situation InteractionIntegration: Personality and situation interact to produce behavior Differences between people make a difference only under certain circumstances Situational specificity: Certain situations can provoke behavior that is out of character for an individual2/10/20096Person-Situation InteractionIntegration: Personality and situation interact to produce behavior Strong situation: Situations in which most people react in a similar way (e.g., grief following loss of loved one) When situations are weak or ambiguous, personality has its strongest influence© 2008 The McGraw-Hill Companies, Inc. All rights reserved.Person-Situation Interaction Three additional ways in which personality and situation interact to produce behavior Selection Evocation Manipulation2/10/20097Person-Situation Interaction Selection: Tendency to choose or select situations in which one finds oneself, as a function of personality Evocation: Certain personality traits may evoke specific responses from others Manipulation: Various means by which people influence the behavior of others; tactics of manipulation vary with personalityAggregation Longer tests are more reliable than shorter ones and are better measures of traits Single behavior or occasion may be influenced by extenuating circumstances unrelated to personality2/10/20098Aggregation Aggregation implies that traits are only one influence on behavior Aggregation also implies that traits refer to the person’s average level Thus, personality psychologists will never be good at predicting single acts or single occasionsMeasurement Issues Trait approach relies on self-report surveys to measure personality Personality psychologists assume that people differ in the amounts of various traits, and so a key measurement issue is determining how much of trait person has2/10/20099Measurement Issues Traits are often represented as dimensions along which people differ Trait psychologists are aware of and address circumstances that affect accuracy, reliability, validity, and utility of self-report trait measuresMeasurement Issues Carelessness Faking On Questionnaires Response Sets Integrity Testing2/10/200910Measurement IssuesCarelessness Method for detecting such problems is an infrequency scale embedded in test Infrequency scale contains items that most people answer in a particular wayMeasurement IssuesCarelessness If a participant answers differently than most, this suggests carelessness Another method for detecting carelessness is to include duplicate items spaced far apart in the survey—if the person answers the same item differently, this suggests carelessness2/10/200911Measurement IssuesFaking On Questionnaires “Fake good”: Attempt to appear better off or better adjusted than one is “Fake bad”: Attempt to appear worse off or less adjusted than one is Method to detect is to a devise scale that, if answered in particular way, suggests fakingMeasurement IssuesResponse Sets Acquiescence: Tendency to agree with items, regardless of content; psychologists counteract by reverse-keying some items Extreme responding: Tendency to give endpoint responses Social desirability: Tendency to answer items in such a way so that one comes across as socially attractive or likable2/10/200912Measurement IssuesTwo Views On Social Desirability Represents distortion and should be eliminated or reduced Valid part of other desirable personality traits, such as agreeableness, and should be studiedBeware of Barnum Statements in Personality Test Interpretations Barnum statement: generality that could apply to anyone2/10/200913Measurement IssuesIntegrity Testing: A Closer Look Integrity tests are surveys designed to assess whether a person is generally honest or dishonest; replaced polygraph When assessed against the “big five” personality traits, integrity is the combination of high conscientiousness, high agreeableness, and low neuroticismPersonality and Prediction Whether someone does well in an employment setting may be determined, in part, by whether a person’s personality traits mesh with job requirements Personality traits may predict who is likely to do well in particular