Unit 11: Testing and Individual Differences

What is Intelligence?

WHAT is intelligence? How can we best assess it? To what extent does it result from heredity rather than environment? What do test scores really mean?

Intelligence… A socially constructed concept What attributes enable success Ability to learn from – experience – solve problems – use knowledge to adapt to new situations. Intelligence Test? IQ?

Is Intelligence One General Ability or Several Specific Abilities? Spearman’s: General intelligence (g) –An intelligence factor that underlies specific mental abilities and is measured by every task. Factor analysis –Statistical procedure that identifies clusters of related items on a test.

Savant Syndrome Condition which a person otherwise limited in mental ability has an exceptional specific skill, such as in computation or drawing

Theories of Multiple Intelligences Gardner’s Eight Intelligences –Linguistic –Logical-mathematical –Musical –Spatial –Bodily-kinesthetic –Intrapersonal –Interpersonal –Naturalist

Is Intelligence One General Ability or Several Specific Abilities? Theories of Multiple Intelligences

Sternberg’s Three Intelligences –Analytical intelligence (academic problem-solving) –Creative intelligence –Practical intelligence Theories of Multiple Intelligences

Emotional Intelligence Perceive emotions –Recognize them in faces/music/stories Understand emotions –Predict them and how they change/blend Manage emotions –Express them in varied situations Adaptive/creative thinking

Is Intelligence Neurologically Measurable? Brain Size and Complexity Brain size and Smarts size?! Brain complexity studies –Neural plasticity –Gray matter: Neural cell bodies -white matter: axons

Is Intelligence Neurologically Measurable? Brain Function Perceptual speed Neurological speed People who process more quickly accumulate more information Processing and Intelligence correlate

Comparing Theories of Intelligence

Assessing Intelligence

The Origins of Intelligence Testing Francis Galton’s intelligence testing –Reaction time –Sensory acuity –Muscular power –Body proportions

Alfred Binet: Predicting School Achievement Indentifying French school children in need of assistance Mental age –Level of performance typically associated with a certain chronological age. Mental aptitude is a general capacity that shows up in various ways.

Lewis Terman: The Innate IQ  Stanford-Binet Test  William Stern –Intelligence quotient (IQ) IQ = (mental age/chronological age) X 100 IQ of 100 is considered average World War I testing -lead to immigration laws

Modern Tests of Mental Abilities Achievement tests –Designed to assess what a person has learned Aptitude tests –Designed to predict a person’s future performance –The capacity to learn

Modern Tests of Mental Abilities David Wechsler Wechsler Adult Intelligence Scale (WAIS) –Wechsler Intelligence Scale for Children (WISC)

Wechler Adult Intelligence Scale

Principles of Test Construction Standardization: Defining meaningful scores by comparison with the performance of a pretested group. Normal (bell) curve: describes the distribution of physical and psychological attributes. –Most near average –Outliers

Normal Curve

Principles of Test Construction Standardization Flynn effect: rising or declining?

Principles of Test Construction Standardization Flynn effect

Principles of Test Construction Reliability: Extent to which a test yields consistent results, as assessed by the consistency of scores on 2 halves of the test, or on retesting. –Scores correlate –Test-retest reliability –Split-half reliability

Principles of Test Construction Validity Extent to which a test measures or predicts what it is supposed to. –Content validity: Behavior of interest –Predictive validity: Predicts the behavior

The Dynamics of Intelligence

Stability or Change? Intelligence testing through life

Stability or Change? Intelligence testing through life

Extremes of Intelligence The Low Extreme Intellectual disability: –Condition of limited mental ability. –IQ score of 70 or below –Difficulty adapting to demands of life –Varies from Mild to profound –1-3%, males 50% more –Mental retardation Down syndrome –Extra copy of 21 st chromosome –Mainstreamed

Extremes of Intelligence Classifications of Intellectual Disability LevelApproximate Intelligence Scores Adaptation to Demands of Life Mild50-70 May learn academic skills up to sixth-grade level. Adults may with assistance, achieve self- supporting social and vocational skills Moderate35-50 May progress to second-grade level academically. Adults may contribute to their own support by laboring in sheltered workshops Severe20-35 May learn to talk and to perform simple tasks under close supervision but are generally unable to profit from vocational training ProfoundBelow 25 Require constant aid and supervision

Extremes of Intelligence The High Extreme Mentally gifted: 1-3% Terman’s study of gifted Self-fulfilling prophecy –“ungifted/gifted” students Appropriate developmental placement –Tracking students

Extremes of Intelligence Classifications of Intellectual Disability LevelApproximate Intelligence Scores Adaptation to Demands of Life Bright Superior Very Superior Genius150+

Genetic and Environmental Influences on Intelligence

Twin and Adoption Studies Identical twin studies –Polygenetic –100% same genes Adoptive children studies

Heritability

Environmental Influences Early environmental influences –Tutored human enrichment –Targeted training Schooling and intelligence –Project Head Start

Group Differences in Intelligence Test Scores Gender Similarities and Differences Spelling Verbal ability Nonverbal ability Sensation Emotion-detecting ability Math and spatial aptitudes

Group Differences in Intelligence Test Scores Ethnic Similarities and Differences Ethnic similarities? Ethnic differences?

The Question of Bias Two meanings of bias –Popular sense –Scientific sense Test-taker’s expectations –Stereotype threat: Self-confirming concern that one will be evaluated based on a negative stereotype.

The End