Session 7 Intelligence and General Ability Testing

Schedule Instruments we use Intelligence instruments Achievement and Aptitude Exam results

Widely Used Measures Community – MMPI, Strong-Campbell, Myers-Briggs, WAIS-R, WISC-IV School – WISC-IV, PSAT, SAT, ACT, CAT, DAT, Strong-Campbell

Overview No agreement in profession on either definition or meaning of intelligence Sometimes called “general ability” because of negative associations with term “intelligence” Debate about meaning of intelligence and intelligence test scores is emotionally charged

Models of Intelligence Psychometric Approaches Developmental Progressions Information Processing Multiple Intelligences

Psychometric Approach Major influence since turn of century Based on mental factors or general mental skills that influence mental performance in a variety of situations Number of factors range from Spearman’s two factors to Guilford’s 180 factors.

Spearman (1927) First to discuss factors Two factors g or general ability factor that influences performance on all intellectual tasks specific factors that influence performance in specific areas but highly correlated with g Intelligence viewed as a homogeneous construct; either you were smart or not

Thurstone (1938) Proposed model of seven primary mental abilities Verbal comprehension Word fluency Number facility Perceptual speed Memory Space Reasoning

Vernon (1950) Hierarchical approach g is first order factor v:ed (verbal/educational aptitudes) and k:m (spatial/mechanical/practical aptitudes)

Cattell (1971) First order factor like g Two second order factors Fluid abilities (Gf) are biologically determined, relatively culturally free and reflected in tests of memory span and spatial abilities Crystallized abilities (Gc) include acquired skills and knowledge, are influenced by cultural, social and educational experiences and reflected in tests of verbal comprehension and social relationships

Guilford (1988) Structure of intelligence theory First dimension is mental operations and contains six forms Mental operations involve five content areas which is the second dimension Finally, there are six possible products, the third dimension, that interact with the combinations of operations and content areas

Developmental progressions Not concerned with psychometric differences in intellectual abilities Interested in how intelligence develops

Piaget Stages of development Sensiomotor Preoperational Concrete operations Formal operations Two intellectual functions Assimilation Accommodation

Other developmentalists Vygosky – curriculum Neisser – biological development Ceci – bioecological (no g but differences in domain-general abilities depending on context)

Information processing Interested in how not what is processed Luria’s two methods of processing Simultaneous (mental ability to integrate input all at once) Sequential (stimuli arranged in serial order to solve problem) Kaufman Assessment Battery for Children (K- ABC) Sternberg’s triarachic theory

Individual Intelligence Testing

Wechsler Scales Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) for kids from 2 years 6 months to 7 years 3 months Wechsler Intelligence Scale for Children- Fourth Edition (WISC-IV) for kids from 6 to 16 Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) for individuals 16 through 89 All 3 have mean of 100 and SD of 15

WISC-IV Full Scale IQ plus Performance and Verbal IQ’s Verbal subtests are Information, Similarities, Arithmetic, Vocabulary, and Comprehension Performance subtests are Picture Completion, Coding, Picture Arrangement, Block Design, and Object Assembly All subtests have mean of 10 and SD of 3 Sample report Technical reports

Stanford-Binet Intelligence Scale

Binet (cont’d) Can use with folks from 2 years through adulthood Includes comprehensive coverage of five factors--Fluid Reasoning, Knowledge, Quantitative Reasoning, Visual-Spatial Processing, and Working Memory (remember Cattell?) Has mean of 100 and SD of 16

Kaufman Instruments Kaufman Assessment Battery for Children-II Can interpret in two ways: Crystallized Ability (Cattell-Horn-Carroll model) for children from a mainstream cultural and language background Luria model which excludes verbal ability Designed for folks from 11 to 85+ years

Kaufman (cont’d)

Difficult to interpret Mean of 100 and SD of 10 Not widely used

Group Intelligence Testing

Group Test Usage School boards who want to evaluate school’s performance examine differences between ability (group IQ tests) and performance (group achievement tests) Screening for further referral

Tests Cognitive Abilities Test, Form 6 (CogAT, 2001) Cognitive Abilities Test, Form 6 K to 12 Separate scores for verbal, quantitative and nonverbal reasoning plus composite Otis-Lennon School Ability Test, Eighth Edition Otis-Lennon School Ability Test, Eighth Edition K to 12 Provides total, verbal and nonverbal scores

Difficulties Can’t observe behaviors that may indicate level of motivation Require more reading Reliability and validity data not as strong as for individually administered tests

Issues in Intelligence Testing

Stability of scores Cross-sectional (people at different age levels tested and scored compared) studies said not stable Longitudinal studies (same people tested throughout lives) said is stable Combination of cross-sectional and longitudinal suggest intelligence is fairly stable

Prediction Academic performance but only 25% of variance is explained by the relationship Occupational success and income some relationship with about 1/4 related to social status variance and 1/6 to income variance Highly related to job performance Mental processing speed important component

Heredity and Environment Appears to be a hereditary influence but is also influenced by environment Environmental factors such as culture, schooling, nutrition, and exposure to certain toxins impact intelligence

Group Differences Gender Females tend to score higher on some verbal tasks while men are better at visual-spatial tasks. Ethnicity African-Americans, Hispanics, and Native Americans tend (as a group) to score lower than do European-Americans and Asian- Americans

Flynn Effect Rise in intelligence test scores In past 50 years has risen by 1 SD Reasons for this rise are unclear