Chapter 9 Intelligence and Psychological Testing

Theories of Intelligence Charles Spearman’s “g” concluded that all cognitive abilities share a common core Surrounding the core are specific abilities rather than general intelligence L.L. Thurstone Rejected the idea of one general factor Suggested a set of six, such as word fluency, general reasoning & spatial ability Increased emphasis on specific abilities

Theories of Intelligence con’t J.P. Guilford asserts intelligence is made up of as many as 150 distinct mental abilities

Theories of Intelligence con’t Cattell & Horn – Two facets of g = fluid & crystallized Fluid intelligence - reasoning ability, memory capacity, speed of information processing Crystallized intelligence - ability to apply acquired knowledge and skills in problem solving Biological Indexes of Intelligence Reaction time and inspection time, “fast is smart” High correlations exist, but more studies are needed

Theories of Intelligence con’t Cognitive Views Focus on HOW people use their intelligence Robert Sternberg Triarchic Theory Contextual (intelligent behaviors in a culture) Experiential (interaction btw. intelligence & experience) Componential (cognitive processes underlying behavior)) *Update: “successful intelligence” = analytical intelligence, creative intelligence, and practical intelligence. (Diagram on next slide)

Theories of Intelligence: Expanding the Concept Howard Gardner’s multiple (8) intelligences argues IQ tests emphasize verbal and mathematical skills and exclude other important skills. Suggests the existence of a number of human intelligences (ex: music, kinesthetic, spatial, linguistic – figure 9.3, p. 376) Daniel Goleman’s emotional intelligence (EQ) ability to perceive and express emotion, assimilate emotion in thought, understand and reason with emotion, and regulate emotion. Marshmallow study

Key Concepts in Psychological Testing Standardization - uniform procedures used in the administration and scoring Test norms - where a score on a test ranks in relation to other scores on that test Standardized group - sample of people on which the norms are based Reliability – a test’s consistency Correlation coefficient (two administrations of the same test are correlated) Validity – test’s ability to measure what it is intended to measure Content validity Criterion-related validity (Predictive ability) Construct validity (measures a hypothetical construct – intelligence)

Principle Types of Psychological Tests Mental ability tests Intelligence – measure general mental ability Aptitude – measure more specific mental abilities Achievement – measure acquired abilities * Although they are intended to measure potential, IQ tests inevitably assess both knowledge and potential. Personality scales Measure motives, interests, values, and attitudes Ex: MMPI, CPI

The Evolution of Intelligence Testing Sir Francis Galton Cousin of Charles Darwin Hereditary Genius (1869) – stated success runs in families, intelligence is inherited Alfred Binet and Theodore Simon published the first intelligence test in 1905 Binet-Simon Intelligence Scale Scores expressed in mental age

Intelligence testing con’t Lewis Terman (1916) Standardized admin. & age-level norms of Binet-Simon test = Stanford-Binet Intelligence Scale Introduced idea of Intelligence Quotient (IQ) =MA/CA x 100 Allows for comparison btw. children/adults of different ages * Individually administered = costly

Intelligence testing con’t David Wechsler (1955) Wechsler Adult Intelligence Scale WAIS Later extended his scales to children Two intelligence test innovations: Nonverbal reasoning test component Tests yield a verbal IQ, performance IQ and general IQ New scoring system based on the normal distribution…the deviation IQ.

Reliability and Validity of IQ tests IQ tests have… Exceptional reliability – correlations into the.90s Qualified validity – valid indicators of academic/verbal intelligence Correlations:.40s-.50s with school success.60s-.80s with number of years in school positively correlated w/ high status occupations * Tests are not good measures of social or practical intelligence and do not measure intelligence in a truly general sense.

Extremes of Intelligence: Mental Retardation Mental retardation - sub average general mental ability accompanied by deficiencies in adaptive skills, originating before age 18. Diagnosis: IQ = 2 or more SD below mean Adaptive skill deficits Origination before age 18 Causes/etiology: Biological organic syndromes: 350 biological conditions that can cause mental retardation have been identified. However, <25% of cases have been pinned to an organic cause. (Note: PKU test) Environmental theories unfavorable environmental factors like neglect, malnutrition, poor medical care, and lower quality schooling MAY contribute to mild retardation.

Mental retardation con’t 4 levels: mild, moderate, severe, profound Mild most common *2-3% pop. retarded/ 85% of that % is mild

Extremes of Intelligence: Giftedness Identification issues – IQ = 2 SD above mean standard (130 + ) Creativity, leadership, special talent????? Stereotypes – weak, socially inept, emotionally troubled Lewis Terman (1925) Longitudinal study of 1500 individuals w/ IQ largely contradicted stereotypes Ellen Winner (1997) Calls for distinction btw. moderately (IQ ) vs. profoundly gifted (IQ ) Notes profoundly gifted tend to be introverted and isolated

Giftedness con’t Giftedness & high achievement – beyond IQ Renzulli (2002) – intersection of three factors high intelligence high creativity high motivation * The three-ring concept of eminent giftedness.

Intelligence: Heredity or Environment? Heredity (a plausible link, NOT a guarantee) Family and twin studies Heritability estimates Environment Adoption studies Cumulative deprivation hypothesis - children raised in deprived environments will experience a gradual decline in IQ as they grow older. * Conversely, children removed from deprived environments and placed in homes that are more conducive for learning show IQ increases. The Flynn effect – a trend, all over the developed world, for IQ scores to increase from one generation to the next. * Hypotheses for why this occurs focus on environmental variables, as evolution does not operate in a generation.

Heredity or Environment? con’t Interaction btw. nurture & nature “Reaction Range” - term used to refer to genetically determined limits on IQ. * The environment determines whether a person will fall at the upper or lower end of their genetically determined range.

Cultural Differences in IQ Heritability as an explanation Arthur Jensen (1969) Controversial argument that cultural differences in average IQ are largely due to heredity. Herrnstein and Murray (1994) – The Bell Curve implied that we are moving toward a meritocracy based on intellect Challenges to theory: Generalizations are too broad…even if IQ is largely due to heredity, group differences may not be Social class and socioeconomic disadvantage are correlated with ethnicity, so environmental variables are not equal between groups. Environment as an Explanation Kamin’s cornfield analogy – socioeconomic disadvantage Steele (1997) - stereotype vulnerability derogatory stereotypes create feelings of vulnerability in the educational domain, undermining group members’ achievement and performance on tests.