Chapter 11 pt. 2: Intelligence Assessment

1. Chapter 11 pt. 2: Intelligence Assessment

2. Assessing Intelligence: Aptitude vs. Achievement Test • Aptitude Tests: are tests designed to predict a person’s future performance. • SAT’s and GRE’s • Achievement Test: a test designed to assess what a person has learned. • Midterm Psych exam, chapter 3 history test, etc.

3. Assessing Intelligence • Wechsler Adult Intelligence Scale (WAIS) • most widely used intelligence test • subtests • verbal • performance (nonverbal) • Also a WISC (Wechsler Intelligence Test for Children).

4. VERBAL PERFORMANCE Picture Completion Picture Arrangement Block Design Object Assembly Digit-Symbol Substitution General Information Similarities Arithmetic Reasoning Vocabulary Comprehension Digit Span Assessing Intelligence- Sample Items from the WAIS

5. WAIS SAMPLE

7. Qualities of A Good Test • To be accepted all psychological tests must be: • Standardized • Reliable • Valid

8. Standardization • Standardization: defining meaningful scores by comparison with the performance of a pretested group. • Your scores are compared with the pretested group who took the test. • Standardized tests usually follow a normal distribution. • Normal Distribution: bell shaped curve that describes the distribution of many physical and psychological properties. Most scores fall near average, and fewer and fewer scores lie near the extreme.

9. Number of scores Sixty-eight percent of people score within 15 points above or below 100 Ninety-five percent of all people fall within 30 points of 100 55 70 85 100 115 130 145 Wechsler intelligence score The Normal Curve (Know My Distributions)

10. Reliability vs. Validity (DON’T MIX THEM UP) • Reliabilitydeals with consistency. assessed by consistency of scores on: • two halves of the test • alternate forms of the test • retesting the same individual • Weschler and Standford Binet test +.9 • Validitydeals with predictability. Does the test measure what it is supposed to measure?

11. Types of Validity • Content Validity: the extent to which a test samples the behavior that is of interest.Would a maneuverability test on a skateboard have content validity for testing to see if your qualified to drive? • Predictive Validity: The success with which a test predicts the behavior it is supposed to predict. • Do high SAT scores correlate with high college grades?

12. Predictive Validity is Based on Criterion • Criterion: the behavior that a test is supposed to predict. Is used to see if test is successful. • What would the criterion be for the GRE’s?

13. The Flynn Effect • Since the advent of intelligence tests, people’s IQ scores have been improving with time (flynn effect). • If standardized with today’s tests, scores 80 years ago would have a average IQ of 76. • Possible Causes?

14. The Flynn Effect

15. Stability of Change? • Can infant tests predict future intelligence? • Picture Test • Starting at Age 4 may predict future IQ • Age 7 scores become stable,but not fixed

16. Low Extreme of Intelligence • Mental Retardation:condition of limited mental ability, indicated by an intelligence score of below 70 and difficulty adapting to the demands of life.

17. Low Extreme of Intelligence • Down Syndrome: condition of retardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup. • Many mentally retarded people with Down Syndrome can adapt to disorder and some have earned college degrees with accomdations…nearly all learn how to read.

18. Degrees of Mental Retardation Level Typical Intelligence Scores Percentage of the Retarded Adaptation to Demands of Life Mild 50-70 85% Most learn academic skills up to sixth-grade level. Adults may, with assistance, achieve self-supporting social and vocational skills. Moderate 35-49 10 May progress to second-grade level. academically. Adults may contribute to their own support by labor in sheltered workshops. Severe 20-34 3-4 May learn to talk and perform simple work tasks under close supervision but are generally unable to profit from vocational training. Degrees of Mental Retardation

19. Smart kids are usually not “weird” Tend to get higher degrees Should gifted children be “tracked” in school? Gifted

20. Similarity of intelligence scores (correlation) Siblings reared together Unrelated individuals reared together Identical twins reared together Identical twins reared apart Fraternal twins reared together Is Intelligence Genetic or Environmental? • Influenced by both, but the most genetically similar have the most similar scores.

21. Genetic Influences • With age, genetic influences become more apparent. • Adopted children’s intelligence scores become more like their biological parents, and identical twins similarities continue to increase as they age. • Still hard to tell what percentage of intelligence comes from genes to account for differences between people (heritability).

22. 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 Child-parent correlation in verbal ability scores Children and their birth parents Adopted children and their birth parents Adopted children and their adoptive parents 3 years 16 years Genetic Influences

23. Environmental Influences • Early Intervention • Head Start • Schooling Effects • Schooling and IQ scores tend to correlate

24. 118 115 112 109 106 103 100 97 IQ gains relative to grade 4 baseline Grade 6 Grade 5 Grade 4 110 115 120 125 130 135 140 145 150 Age in months Schooling Effect

25. Group Differences in IQ Scores • Ethnic Similarities and Differences • Racial groups differ in IQ scores • Higher scoring ppl and groups tend to have higher incomes and education • Individual differences within a race are much greater than differences between races • Asian students outperform North American student on math tests • IQ scores have increased • White and blacks tend to score the same on infant IQ tests

26. Variation within group Variation within group Seeds Poor soil Fertile soil Difference within group Group Differences in Intelligence Scores Are Probably Mostly Attributed to the Environment

27. Group Differences in IQ Scores • Gender Similarities and Differences • No big differences • Girls are better spellers, more verbal, more sensitive to senses • Boys tend to be in lower classes more and talk later and stutter more • Math and Spatial Aptitudes • No huge differences • Boys tend to do a bit better on math • Girls better on memory and picture recognition • Women better at reading facial expressions

28. The Question of Bias 2 definitions 1. Tests detect not only innate differences in IQ but also differences caused by cultural experiences • Yes. Test do not account for differences in cultures, which may make them bias 2. Is a test less valid for some groups than for others. • No. The predictive value of a standard IQ testS is roughly the same for black and whites and rich and poor…….

29. The Question of Bias • Stereotype Threat • A self confirming concern that one will be evaluated based on a negative stereotype • Black student's taking verbal test • Women and math scores