Intelligence and General Ability Testing

Chapter 7

Models of Intelligence

Psychometric approach

Cattel-Horn-Carroll model

Developmental progressions

Information processing

Other theories

Psychometric Approach

Based on premise that intelligence can be described in terms of mental factors (Bjorkland, 2005)

Spearman’s (1927) 2-factor model g (general ability factor) Specific factors

Guilford’s (1988) structure-of-intelligence theory Mental operations Content areas Products

Psychometric Approach (cont.)

Thurstone’s (1938) 7 primary mental abilities Verbal comprehension Word fluency Number facility Perceptual speed Memory Space Reasoning

Vernon’s (1950) hierarchical theory g v:ed & k:m

Cattel-Horn-Carrol Model

One of the more influential contemporary theories

g is composed of two second-order factors Fluid abilities (Gf) Crystallized abilities (Gc)

Developmental Progressions

Intelligence can be better understood by examining how intelligence develops; learning and environment influence the process

Jean Piaget’s (1972) theory Stages of development:

Sensorimotor Preoperational Concrete Formal operations

Intellectual functions: Assimilation Accomodation

Ceci’s (1990, 1993) bioecological model Intellectual abilities are highly influenced by context

Information-Processing

These models focus on how individuals process information

Luria’s (1966) theory Simultaneous processing Sequential processing

Sternberg’s (1985, 1988) triarchic theory Internal world of individual or mental processes

that underlie intelligence Experiential subtheory Individual’s contextual or external world

Other Theories Gardner’s (1993) theory of 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”

1. Linguistic2. Logical-mathematical3. Musical4. Spatial5. Bodily-kinesthetic6. Interpersonal7. Intrapersonal8. Naturalist9. 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

Kaufman Instruments

Additonal Individual Instruments

Wechsler Scales

Wechsler Adult Intelligence Scale – III (WAIS-III, 1997)

Wechsler Intelligence Scale for Children – IV (WISC-IV, 2003)

Wechsler Preschool and Primary Scale of Intelligence – III (WPPSI-III, 2002) Wechsler Memory Scale – III (1997)

WAIS-III

Verbal IQ, Performance IQ, Full Scale IQ

Composite Scores: Verbal Comprehension

Index Perceptual Organization

Index Working Memory Index Processing Speed Index

Uses basal and ceiling levels.

Scales: Verbal

Vocabulary Similarities Arithmetic Digit Span Information Comprehension Letter-Number

Sequencing Performance

Picture Completion Digit-Symbol Coding Block Design Matrix Reasoning Picture Arrangement Symbol Search Object Assembly

WISC-IV

Full Scale IQ – no longer use Verbal IQ and Performance IQ like earlier versions; now use Four Index Scores:

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

areas1. Fluid Reasoning2. Knowledge3. Quantitative Reasoning4. Visual-Spatial Processing5. Working Memory

Basal level, ceiling level, routing test

Kaufman Instruments

Kaufman Assessment Battery for Children, Second Edition (KABC-II, 2004)

Kaufman Adolescent and Adult Intelligence Test (KAIT, 1993)

Not as widely used as Wechsler instruments

Integration of different theoretical approaches

KABC-II

Designed to assess children 3 to 18

Yields 4 or 5 scales depending on whether the Cattell-Horn-Carroll (CHC) or Luria approach is used

CHC perspective; composite = Fluid-Crystallized Index

Short-Term Memory Visual Processing Long-term Storage and Retrieval Fluid Reasoning Crystallized Abilities

Luria perspective; global score = Mental Processing Index

Sequential Processing Simultaneous Processing Learning Ability Planning Ability

KAIT

Designed for individuals 11-85 years

3 intelligence scales: Fluid (Gf) Crystallized (Gc) Composite

6 subtests: 3 assess fluid intelligence 3 assess crystallized intelligence

Additional Individual Instruments

Differential Ability Scales-Second Edition (Elliot, 2006)

Slossen Intelligence Test-Revised, Third Edition (Nicholson & Hibpshman, 1990)

Raven’s Standard Progressive Matrices (Raven, Court, & Raven, 1983)

Peabody Picture Vocabulary Test – III (Dunn & Dunn, 1997)

Test of Nonverbal Intelligence – 3 (Brown, Sherbenou, & Johnsen, 1997)

Group Intelligence Testing

Given more often than individual intelligence tests, usually in schools

Not as easy to monitor test-taker’s behavior during assessment

Require more reading than individual tests

Must consider other factors of individual (culture, gender, background info, language proficiency) in interpreting results

Group Intelligence Testing (cont.)

Cognitive Abilities Test (CogAT)

Otis-Lennon School Ability Test, 8th edition (OLSAT-8)

Naglieri Nonverbal Ability Test (NNAT)

Multidimensional Aptitude Battery – II (MAB-II)

Wonderlic Personnel Test (WPT)

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

What Do Intelligence Scores Predict?

Intelligence tests appear to be related to academic performance

The relationships among IQ scores, occupational success, and income are not simple

Validity generalization Refers to findings that the same test score data may be

predictive for all jobs – if a test is valid for a few occupations, the test is valid for all jobs in that cluster.

GATB validity coefficients can be generalized to other occupations.

Concerns regarding the use of the “Job Family method” and minority groups

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 .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

Other effects of schooling; quality of schools

Family environment

Environmental toxins

Are There Group Differences in Intelligence?

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, etc.

What is the Flynn effect?

James Flynn (1984, 1987) first to identify steadily increasing intelligence test scores in recent years

Gains in IQ not reflected in gains in achievement

Possible explanations: better nutrition, more test sophistication, changes in education and opportunities, changes in parenting practices