Testing & Indiv Differences

11-1 Testing & Indiv Differences Intelligence • the ability to learn from experience, think rationally, and adapt to changes in the environment

11-1 12 interesting facts about IQ • IQ is associated w/ some simple abilities • School attendance correlates w/ IQ • IQ is not influenced by birth order. • IQ is related to breast feeding • IQ varies by birthdate. • IQ evens out with age. • Intelligence is plural, not singular. • IQ is correlated w/ head size. • Intelligence scores are predictive of real world outcomes. • Intelligence depends on context. • IQ is going up. • IQ may be influenced by school caféteria menu.

11-1 11-1 Intel Objectives 1. Trace the origins of intelligence testing, and describe the Stern formula for the intelligence quotient. 2. Discuss whether intel should be considered a general mental ability or many specific abilities. 3. Identify the factors associated with creativity, and describe the relationship between creativity and intelligence. 4. Describe efforts to correlate intelligence with brain anatomy, brain functioning, and cognitive processing speed 5. Distinguish between aptitude and achievement tests, and describe modern tests of mental abilities such as the WAIS. 6. Describe test standardization, and explain the importance of appropriate standardization samples for effectively interpreting intelligence test scores. 7. Distinguish between the reliability and validity of intelligence tests, and explain how reliability and validity are assessed.

11-1 Origins of Intelligence Testing • What is Intel? • the ability to learn from experience, think rationally, and adapt to changes in the environment • Alfred Binet • around 1900 French gov. made a law saying all children must attend school • all kids were not on the same level • Binet’s job was to fig out who needed special help • Dev test to meas mental age • -intellectual level in years that a child is functioning on

11-1 Origins of Intelligence Testing • Mental Age • child who does as well as the average 8-year-old is said to have a mental age of 8 • Lewis Terman • Stanford prof who Revised Binet’s test for Calif schoolchidren & renamed it the Stanford-Binet IQ Test which gave kids an Intelligence Quotient

11-1 Origins of Intelligence Testing • IQ = mental age (MA) X 100 • Chronological age (CA) • Was dev by William Stern • therefore, average intelligence should be 100 • formula works well for children, but not adults • Today’s tests produce a mental ability score based on the test-takers performance vs. the average performance of others of the same age • 50% of pop. score between 90-110 • 67% of pop. score between 85-115

11-1 Origins of Intelligence Testing • Terman was a supporter of the eugenics movement [influenced by Francis Galton’s Hereditary Genius (1869) (Galton is Darwin’s Cousin)] • movement that proposed measuring human traits and using the result to encourage or discourage people from reproducing • in its pure form, eugenics was supposed to reduce crime and homelessness • but it ended up being a tool of racism instead • US government tested immigrants when looking for recruits for WWI • led to 1924 immigration law greatly limiting immigrants from Southern and Eastern Europe

11-1 What is Intelligence? • What is Intelligence? • -def. Of intelligence is a socially constructed concept • -the word means different things in different cultures • -usually involves characteristics that make people successful in those cultures • We must be careful not to reify IQ Scores >>Reification: seeing an abstract, material concept as something concrete – it’s just a score on a test, not something concrete that someone has • ***a major debate among psychologists*** • Is intelligence a single overall ability or several specific abilities?

11-1 What is Intelligence? Charles Spearman • believed that there was a general intelligence or “g” • -this g factor underlies all specific factors • Evidence: people who score high in one specific area also score high in others.

11-1 What is Intelligence? • A. Factor-Analysis • -a statistical procedure that identifies clusters of related items on a test that measure a common ability • -used to find out whether there might be a general ability factor that runs throughout our specific mental abilities • Spearman’s 2 Factor Theory of theory intelligence • -Spearman helped develop factor-analysis to support g factor theory • -said intelligence was made up of 2 factors • g factor – general ability • s factor – specific ability

11-1 Are There Multiple Intelligences? • g factor underlies the specific abilities • -said people who score high on one s factor usually do well on others as well • -he attributed this to the g factor

11-1 What is Intelligence? - Thurstone • Thurstone’s Theory of Primary MentalAbilities identified 8 factors that make up intelligence • 1)visual-spatial ability • 2)perceptual speed • 3)numerical ability • 4)verbal meaning • 5)memory • 6)word fluency • 7)deductive reasoning • 8)inductive reasoning • said it is possible to be very high in one factor and low in another

11-1 What is Intelligence? – Broadened Theories: Gardner Gardner’s Theory of Multiple Intelligences • said there are 8 different types of intelligence • 1)linguistic any famous writer • 2)logical-mathematical Einstein • 3)visual-spatial Picasso • 4)body-kinesthetic Jordan/ Surgeon/ ballerina • 5)musical-rhythmic any great composer • 6)interpersonal Gandhi • 7)intrapersonal Freud • 8)Nature Darwin • thought each intelligence was based in different parts of the brain & each intelligence varies in intensity in every person

11-1 What is Intelligence? – Broadened Theories: Sternberg Sternberg’s Triarchic Theory of Intelligence -said there are 3 aspects of intelligence 1)analytical intelligence -academic problem solving skills 2)creative intelligence -being able to adapt quickly to new situations and come up with original ideas 3)practical intelligence -everyday tasks *Said Trad tests test 1 but not 2&3 which are better predictors of vocational success

11-1 What is Intelligence? – Broadened Theories: Emo Intel Emotional Intelligence (Daniel Goleman) • interested in finding out why very intelligent people aren’t always successful in life • listed 5 areas needed for life success • 1)self-awareness • 2)self-motivation • 3)impulse control • 4)mood management • 5)people skills

11-1 FYI: Creativity’s Relnshp w/ Intel • Creativity – ability to produce novel & valuable ideas • Intrinsically motivated • Intelligence and Creativity Pos Correlated Through IQ of 120 (relnshp wkns beyond 120)

11-1 Biological Correlates • 2 Correlates: Brain Size, Processing Speed (Perceptual Speed & Neurological Speed) 1. Brain Size • Early 1800s Franz Gall and his school of phrenology believed that they could tell your intelligence and other characteristics about you by the size and shape of your skull • modern studies do show a slight correlation (+.15) b/w head size (relative to body size) and intelligence • however, there is more inside your skull than just the brain • newer studies using MRI technology to measure actual brain size reveal a correlation of +.44

11-1 Biological Correlates Interesting Info: Einstein’s brain was 15% larger than average in the parietal lobes lower region (math and spatial information processing located here) -other areas of his brain were smaller than average -may indicate why he was so slow in learning to speak

11-1 Biological Correlates 2. Processing Speed positively correlated with Intel Diff b/w Sink & Wink • ‘quick wits’ • higher verbal ability scores -PET scans have revealed that high IQ performers use less glucose when completing cog. tasks than do average people

11-1 Mask Stimulus Question: Long side on left or right? Biological Correlates 2 cont’d. Processing Speed :Perceptual Speed • +.4 correlation b/w quick perceptual speed and intelligence • People who can perceive the stimulus very quickly tend to score somewhat higher on intelligence tests

11-1 Biological Correlates 2. Cont’d Processing Speed : Neurological Speed -Pushing a button when an X Appears on a Screen

11-1 Assessing Intelligence Aptitude tests- predict your ability to learn a new skill Achievement tests- intend to reflect what you have learned

11-1 Assessing Intelligence • the most widely used intelligence test today is the Wechsler Adult Intelligence Scale (WAIS) • test consists of 11 subtests • Thought trad intel tests were biased for native Eng spkrs so he created a nonverbal, performance section • gives an overall score, but also gives separate verbal and performance scores • if your verbal score is vastly different than your performance score it may indicate a learning problem • -Figure 11.2 on page 433 7th ed or 436 8th ed lists examples of the 11 subtests

11-1 VERBAL PERFORMANCE Picture Completion Picture Arrangement Block Design Object Assembly Digit-Symbol Substitution General Information Similarities Arithmetic Reasoning Vocabulary Comprehension Digit Span From Thorndike and Hagen, 1977 Assessing Intelligence: Sample Items from the WAIS

11-1 Assessing Intelligence • Standardization- process of defining meaningful scores relative to a pretested group • -basically setting a baseline • -if the test is standardized it should result in a normal distribution (and a normal curve) • Normal Curve • the symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes • most scores fall near the average, and fewer and fewer scores lie near the extremes

11-1 The Normal Curve

11-1 Assessing Intelligence • mean score is 100 on IQ test • 50% of pop. 90-110 • 68% of pop. 85-115 • 96% of pop. 70-130 • 2% < 70 mental retardation • 2% > 130 gifted

11-1 Getting Smarter?- “ TheFlynn Effect” - IQ Scores Raise 20 pts per gen… why??

11-1 Assessing Intelligence Good Tests are Reliable and Valid Reliability~Consistency 1). Test-retest reliability -researchers give participants the same test or another form of it and compare the scores -the higher the correlation b/w scores the higher the reliability 2). Split-half scores -split the test in half and see if odd question scores are consistent with even question scores -Stanford-Binet and WAIS both have about +.9 reliability

11-1 Assessing Intelligence Reliability Cont’d • Equivalent-Form Reliabilty • Test-Retest Reliability

11-1 Assessing Intelligence Validity~ Accuracy --extent to which the test measures what it is supposed to be measuring 1. content validity-extent to which a test samples the behavior of interest ex. Road test for a driver’s license • predictive validity- the success with which a test predicts the behavior it is designed to predict • assessed by computing the correlation between test scores and the criterion behavior • also called criterion-related validity ex. An aptitude test for a job How well the SAT predicts college performance Fyi-SAT has a +.5 correlation w/ undergrad GPA (freshman yr)

11-1 10 9 8 7 6 5 4 3 2 1 0 Greater correlation over broad range of body weights Football linemen’s success Little correlation within restricted range 180 250 290 Body weight in pounds Assessing Intelligence • As the range of data under consideration narrows, its predictive power diminishes

11-2 11-2 8. Distinguish between the reliability and validity of intelligence tests, and explain how reliability and validity are assessed. 9. Discuss evidence for both genetic and environmental influences on intelligence. 10. Describe group differences in intelligence test scores, and show how they can be explained in terms of environmental factors. 11. Discuss whether intelligence tests are culturally biased.

11-2 Assessing Intelligence • Can a test have high reliability but low validity? Yes • Can a test have low reliability but high predictive validity? No • Could have content validity if it is measuring what its supposed to • See Barron’s Manual for more in depth on Reliability & Validity if needed

11-2 Stability v. Change • 2-7 mo old who habituates (grows bored w/ picture – stares at it for shorter pd of time) faster scores higher IQ @ 11 • Early reading better predictor of Intel than talking (Einstein) • By age 4, intel tests predict adolescent & adult scores • After age 7 IQ scores stabilize • 11 yr old – 77 yr old (+.73 correlation) • SAT-GRE (+.86 correlation)

11-2 Extremes of Intel MR (Mental Retardation) • 1% of pop below 70 & can’t live indep (there are 2% total below 70) • physical cause sometimes Down Syndrome (extra chrom) • FAS--Leading known cause of MR Gifted • Can be isoloated/introverted/ in own world Eg. Piaget studied birds/ fossils @ 7 and pub scient art @15 • However, most gifted thrive socially Tracking (Academic) • Doesn’t help Hi IQ kids, hurts low IQ kids (self-fulfilling prophecy) >>why there is no A.T. in Jap & China in elem sch

11-2 Other Tests Personality Tests MMPI Minnesota Multiphasic Personality Inventory Myers-Briggs Personality Inventory Projective Tests- Used by Psychoanalysts to Tap Unconscious • TAT • Rorschach Inkblot >>personality slides

11-2 The Dynamics of Intelligence • Mental Retardation • a condition of limited mental ability • indicated by an intelligence score below 70 • produces difficulty in adapting to the demands of life • varies from mild to profound • FAS is leading known cause of MR • Down Syndrome • retardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup

11-2 The Dynamics of Intelligence

11-2 Genetic Influences • The most genetically similar people have the most similar scores • Also: Higher correlation than siblings reared together shows environmental (nurture) inf

11-2 Genetic Influences • Heritability • the proportion of variation among individuals that we can attribute to genes • Doesn’t pertain to indiv but as to why 2 indivs or groups differ • Boys in barrel example – heritability of intel 100% (diff is 100% attributable to genes)

11-2 Genetic Influences

11-2 Environmental Influences • Extra Early Childhood instruction doesn’t produce extra intellectual dev over a normal env <<but>> a subnormal env can produce cog delays • >>Head Start Program • Intel inc during school year and dec during summer • Flynn Effect – results from more people aware of this info

11-2 Environmental Influences • The Schooling Effect

11-2 Ethnic Similarities and Differences • Bell curve for whites is centered around 100, for blacks: 85 • Flynn Effect: 20 pts smarter than last generation • To what do we attribute F.E (generational gap)? • To what do we attribute racial gap? Facts: • Indiv diff w/in races > than those b/w races • Group differences provide little basis for judging individuals (women outlive men by six years but knowing an individual’s gender doesn’t tell you how long they’ll live.)

11-2 Variation within group Variation within group Seeds Poor soil Fertile soil Difference within group Group Differences • Group differences and environmental impact

11-2 Gender Differences • Males=Females as group on math test mean scores • F higher on computation, M on prob solving (Int fact: males have a gr8er differentiation w/in group) • Differences can be explained in socialization differences b/w males & females • Males better on spatial tasks (evol per: hunting in 3D space, bio per: prenatal male sex hormones) • Females better on emotion detecting (evol per: women’s ability to det emotions helped them read emo in infants & potential lovers)

11-2 Standard Responses Group Differences • Sample Test of Spatial Abilities: The Mental Rotation Test Which two of the other circles contain a configuration of blocks identical to the one in the circle at the left?

11-2 Group Differences • Stereotype Threat • A self-confirming concern that one will be evaluated based on a negative stereotype ~”self-fulfilling prophecy”

Testing & Indiv Differences