Intelligence & General Ability Testing PSY 504: Psychological Measurement

Models of Intelligence Cattel-Horn-Carroll Model Sternberg’s Triarchic Theory Ceci’s Bioecological Model Gardner’s Multiple Intelligences

Cattell-Horn-Carroll Model One of the more influential contemporary theories g is composed of two second-order factors Fluid abilities (Gf) Biologically determined and affect all fields of relational perception Relatively culture free and often reflected in memory span and spatial thinking tests Crystallized abilities (Gc) Include acquired skills and knowledge that are influenced more by cultural, social, and educational experiences Representative tests include verbal comprehension and social relationships

Sternberg’s Triarchic Theory Componential Intelligence – ability to process information at the metacomponent, performance, and knowledge-acquisition levels; ability to think abstractly and process information effectively Analytical/Conventional Intelligence (“Book Smarts”) Experiential Intelligence – relationship between experience and intelligence; ability to formulate new ideas and new solutions to problems; ability to combine new information Creative Intelligence Contextual Intelligence – contextually bound; ability to adapt to changing environmental conditions and to shape the environment; ability to understand people Practical Intelligence (“Street Smarts”)

Ceci’s Bioecological Model Biological factors have a major influence on intelligence, but there is no single, underlying factor (g), nor is intelligence highly heritable There are no intelligent people, only people who are intelligent in certain domains Intellectual abilities are highly influenced by context in which they are performed

Gardner’s Multiple Intelligences Any set of adult competencies that are valued in a culture merits consideration as a potential intelligence 9 relatively independent “frames of mind” Verbal--Linguistic Logical--Mathematical Musical--Rhythmic Visual--Spatial Bodily--Kinesthetic Interpersonal Intrapersonal Naturalist Existential Measures need to value intellectual capacities in a wide range of domains, and the methods should be appropriate for the domain

Individual Intelligence Testing Wechsler Scales Stanford-Binet Intelligence Scale

Wechsler Scales Wechsler Preschool and Primary Scale of Intelligence – IV (WPPSI-IV) Wechsler Intelligence Scale for Children – V (WISC-V) Wechsler Adult Intelligence Scale – IV (WAIS-IV) Wechsler Memory Scale – IV (WMS-IV)

WISC-V Full Scale IQ – based on the 5 Primary Index Scales (16 core subtests)

WAIS-IV Full Scale IQ – based on the 4 Index Scores (10 core subtests; 5 supplemental)

Wechsler Scales Reliability Validity Conclusions Full Scale IQs on the entire battery have reliabilities that range from 0.90-0.96 The Index scores have reliabilities that range from 0.85-0.92 Validity Conclusions Much strength is attributed to the Wechsler Scales based upon the size and representativeness of the standardization samples (especially adult and preschool populations); and technical qualities of their test construction procedures Very popular intelligence scales = much research

Wechsler Scales Many ancillary materials: computer-assisted interpretive programs, manuals for training examiners, and interpretive guides Some criticism due to demands for links between assessment instruments and intervention strategies (hence, movement towards Index scores) i.e., lack of theoretical grounding = influences interpretation Some do not think a theoretical grounding is necessary

Stanford-Binet Intelligence Test – 5 For use with individuals 2 years – 85 years Verbal IQ, Nonverbal IQ, Full Scale IQ Five factors for both verbal and nonverbal areas: Fluid Reasoning Knowledge Quantitative Reasoning Visual-Spatial Processing Working Memory Basal and ceiling levels

Stanford-Binet Intelligence Test – 5 Reliability Composite scores on the entire battery have reliabilities at all age levels, ranging from 0.95-0.99 Most subtests have reliabilities from the high 0.80s to low 0.90s Validity Conclusions Correlates well with measures of achievement Can distinguish between mentally retarded, gifted, and neurologically impaired persons Instrument of choice for evaluating gifted children because of the high ceiling provided by the age range of the test Lacks floor items that are low enough to diagnose mental retardation among the youngest test takers

Is Intelligence Stable? Infants and young children have the least stable intelligence test scores Early research indicated intelligence gradually declines after age 20 – not supported by later research More recent research indicates intelligence gradually increases from childhood to middle age and then levels off Declines tend to occur in areas of fluid intelligence after the age of 65 Fluid – tests that require speed of processing and mental manipulation Crystallized – tests that measure experience and knowledge

What Do Intelligence Scores Predict? Intelligence tests appear to be related to academic performance with correlations near 0.50 (remember, this means on 25% of the variance is explained) The relationships among IQ scores, occupational success, and income are not simple

Is Intelligence Hereditary? One of the most controversial issues in intelligence testing Determining estimates of the genetic contribution to intelligence is difficult In general, the heritability indexes for intelligence tend to be approximately 0.50 Both genetic and environmental factors have significant effects on intellectual development, with IQ scores seemingly to be related to the interaction between the two

What Environmental Factors Influence Intelligence? Culture and language School attendance Children who attend school regularly have higher tests scores than children who attend intermittently Important to note that not all schooling is alike and that the quality of the school experience also influences IQ scores Family environment Severely neglectful or abusive environments can negatively affect children’s cognitive development Environmental toxins Exposure to lead and prenatal exposure to large amounts of alcohol have been well documented to have deleterious effects on children

Are There Group Differences in Intelligence? Important to note that within-group variance is often greater and between-group variance Gender There do not appear to be general intellectual differences between men and women Men may be better at visual-spatial tasks Women may be better at verbal tasks Ethnicity African-Americans, Hispanics, and Native Americans tend to score lower on intelligence tests than European-Americans or Asian-Americans Differences often due to socioeconomic influences, linguistic factors, culture factors, and possibly “test bias”

The Flynn Effect James Flynn was the first to identify steadily increasing intelligence test scores across generations From the 1940s to early 21st century, the average IQ score has increased more than one full standard deviation Gains in IQ not reflected in gains in achievement Possible explanations: better nutrition, decrease in the intensity of infectious diseases, more test sophistication, changes in education and opportunities, changes in parenting practices, more complex and stimulating environment *There may now be a reversed Flynn effect – i.e., decline in IQ scores, which may have started in the 1990s