WIC03 9/29/06 9:52 AM Page 85 INDUSTRIAL PSYCHOLOGY 3 Individual Differences and Assessment 86 Part 2 4 Understanding Performance 161 5 Performance Measurement 211 6 Staffing Decisions 259 7Training and Development 292 WIC03 9/29/06 9:52 AM Page 86 INDIVIDUAL DIFFERENCES AND ASSESSMENT MODULE 3.1: AN INTRODUCTION TO Group versus Individual Tests 119 INDIVIDUAL DIFFERENCES Paper and Pencil versus Performance Tests 120 Some Background 87 Testing and Culture 120 Differential Psychology, Psychometrics, and I-O Psychology 88 International Assessment Practices 123 Identifying Individual Differences 89 MODULE 3.4: ASSESSMENT Varieties of Individual Differences 89 PROCEDURES MODULE 3.2: HUMAN ATTRIBUTES Assessment Content versus Process 125 Abilities 93 Assessment Procedures: Content 125 Cognitive Abilities 93 Cognitive Ability Tests 125 Intelligence as “g” 93 Knowledge Tests 127 Is “g” Important at Work? 94 Tests of Physical Abilities 127 Is “g” as Important in Other Countries Psychomotor Abilities 128 as It Is in the U.S.? 95 Personality 128 3 Can Your Level of “g” Change? 95 Practical Issues Associated with Cognitive Abilities beyond “g” 95 Personality Measures 129 Physical, Sensory, and Psychomotor Integrity Testing 132 Abilities 97 Emotional Intelligence 134 Physical Abilities 97 Interests and Values 135 Sensory Abilities 98 Individual Assessment 136 Psychomotor Abilities 99 Interviews 137 Personality and Interests 99 Interview Content 137 Personality 99 Interview Process 139 The Five Factor Model 100 Assessment Centers 140 Vocational Interests 105 Work Samples and Situational Tests 143 Additional Attributes 107 Work Sample Tests 143 Skills 107 Situational Judgment Tests 144 Knowledge 107 MODULE 3.5: SPECIAL TOPICS Experience 108 IN ASSESSMENT Competencies 109 Emotional Intelligence 110 Incremental Validity 148 Biographical Data 149 MODULE 3.3: FOUNDATIONS OF Grades and Letters of ASSESSMENT Recommendation 152 The Past and The Present of Testing 113 Minimum Qualifications 152 What Is a Test? 115 Useless Assessment Practices: Graphology and the Polygraph 153 What Is The Meaning of a Test Score? 115 Drug and Alcohol Testing 154 Test Users and Test Interpretation 116 Computer-Based and Internet What Is a Test Battery? 116 Assessment 155 Where to Find Tests 118 Who Is a Candidate? 158 Administrative Test Categories 119 Computer Adaptive Testing 158 Speed versus Power Tests 119 Testing and Demographic Differences 159 WIC03 9/29/06 9:52 AM Page 87 An Introduction to MODULE Individual Differences 3.1 hat do Britney Spears, the Pope, Yo-Yo Ma, Stephen King, Carmello Anthony, George W W. Bush, your grandmother, and your instructor have in common? Not much. They are different in abilities, interests, experiences, personality, age, gender, race, and back- grounds. Indeed, the only thing we can say with certainty about these individuals is that they are substantially different from one another. We would not expect your grandmother to try out for an NBA team, or Stephen King to officiate at a religious service, or your instructor to meet with heads of state of foreign countries. Many psychologists, including I-O psy- chologists, believe that the differences among individuals can be used, at least in part, to understand and predict their behavior. But it isn’t good enough to say simply that people are different. You don’t have to be a psychologist to recognize that. Some types of differences prove more useful than others in predicting and understanding behavior. The differences among people on various at- tributes like intelligence, personality, and knowledge are important in understanding a wide variety of socially important outcomes (Lubinski, 2000), including: •academic achievement; • intellectual development; •crime and delinquency; •vocational choice; • income and poverty; •occupational performance. This chapter will deal first with the concept of individual differences, and then with how INDIVIDUAL DIFFERENCES the assessment of these differences can help to predict occupational performance. Dissimilarities between or among two or more SOME BACKGROUND people. Psychology began in a laboratory in Germany in 1876. The father of the discipline, Wil- helm Wundt, was anxious to show that psychology was different from philosophy and med- icine. Since this was a new science and the existing physical sciences like chemistry, biology, and physics had discovered many general principles that enhanced their importance,Wundt set out to uncover general principles of human behavior as well. He developed techniques for studying the sensations and reactions of people, examining the dimmest light that in- dividuals could see, the faintest sound they could hear, and how quickly they could react to a signal. But those who assisted in conducting his experiments quickly discovered that not everyone had the same reaction time, or could see the same dim light, or hear the same soft tone. In other words, they discovered that there were differences among individuals. 87 WIC03 9/29/06 9:52 AM Page 88 88 CHAPTER 3 INDIVIDUAL DIFFERENCES AND ASSESSMENT These differences detracted from the precise results Wundt sought, but to one of his students they represented a fascinating discovery. James McKeen Cattell (1860–1944), an American who received a PhD in psychology under Wundt’s direction, soon began meas- uring and charting the differences among people using “psychological” variables. In 1890 MENTAL TEST Cattell developed the concept of a mental test as a way of charting these differences. Since Instrument designed to the subject matter of this research was differences, the study of differences became known measure a subject’s ability as differential psychology (Landy, 1997). to reason, plan, and solve After leaving Wundt’s laboratory at the University of Leipzig, Cattell went to England problems; an intelligence and worked with another researcher very interested in individual differences, Francis Gal- test. ton. Galton was gathering information that would support his cousin Charles Darwin’s DIFFERENTIAL PSYCHOLOGY radical theory of evolution. In earlier years, Galton had measured inherited characteristics Scientific study of like height, weight, reach, and hair color. With his new mental test, Cattell was able to ex- differences between or pand the number of inherited characteristics that he could examine. After working with among two or more Galton for several years in developing a comprehensive mental test, Cattell returned to people. America and used this test to measure the intelligence of incoming college students. He INTELLIGENCE believed that he could use the resulting scores to help students choose curricula and to predict who would successfully complete college. Cattell had developed methods of meas- The ability to learn and adapt to an environment; uring mental ability, placing it on a scale or metric.As a result, the actual measurement often used to refer to of abilities became known as psychometrics. general intellectual While other early psychologists began to focus on pathological aspects of mental func- capacity, as opposed to tion, the pioneers of differential psychology were primarily interested in the mental abil- cognitive ability or mental ities of “normal” people. Several were aware of Cattell’s work in measuring intelligence. In ability, which often refer to more specific abilities France, Alfred Binet was measuring mental abilities of French school children. Lewis Ter- such as memory or man was conducting similar studies in California with a translation of Binet’s test. Hugo reasoning. Munsterberg was measuring the abilities of trolley drivers in order to predict the likeli- hood of accidents. When the United States entered the First World War in 1917, the lead- MENTAL ABILITY ing industrial psychologists of the time persuaded the Army to use an intelligence test to Capacity to reason, plan, screen recruits and determine who should attend officer’s candidate school. Two years af- and solve problems; cognitive ability. ter the war’s end, Walter Dill Scott, one of the founding fathers of I-O psychology, pro- claimed that “possibly the single greatest achievement of the American Psychological METRIC Association is the establishment of individual differences” (Lubinski, 2000). Standard of measurement; In the postwar years, intelligence tests were adapted for use in selecting individuals a scale. for jobs with government and industry. By 1932 measuring the differences in intelligence among individuals in order to predict things like accidents and productivity was a well- PSYCHOMETRICS established practice (Landy, 1997; Viteles, 1932). As we will see later in the chapter, intel- Practice of measuring a ligence is still one of the most generally assessed characteristics of job applicants. characteristic such as mental ability, placing it on a scale or metric. DIFFERENTIAL PSYCHOLOGY, PSYCHOMETRICS, INTELLIGENCE TEST Instrument designed to AND I-O PSYCHOLOGY measure the ability to Nearly a century later, measuring the differences among individuals to predict later be- reason, learn, and solve havior (“psychometrics”) remains one of the most common frameworks applied by I-O problems. psychologists. It is different from the framework used by an experimental psychologist. The experimental psychologist usually designs an experiment that will show how all people are alike in their response to a stimulus, and looks outside the individual to the stimulus as a way to explain behavior. In contrast, the differential psychologist is person- centered, looking for