Unit 6: Testing and Individual Differences

1. Unit 6: Testing and Individual Differences Module 32: Assessing Intelligence

2. Assessing Intelligence • Intelligence is whatever an intelligence test meaures. • Intelligence Test: A method for assessing an individual’s mental aptitudes and comparing them with those of others, using scores.

3. Origins of Intelligence Testing • When laws for mandatory schooling began, testing was needed to separate those who needed “extra” attention and those who didn’t. • Testing was a way to minimize bias. • Alfred Binet: French psychologist who invented the first practical intelligence test to identify students who needed special help.

4. Origins of Intelligence Testing • Alfred Binet (below) and Theodore Simon developed questions that would predict children’s future progress in the Paris school system. • The Binet-Simon Scale measured a child’s mental age.

5. Origins of Intelligence Testing • Mental age: the age that most typically corresponds to a given level of performance. • A child who does as well as the average 8 year old has a mental age of 8. • A child can have a mental age smaller or larger than their chronological age. • Mental age of 8, chronological age of 6.

6. Origins of Intelligence Testing • Lewis Terman: Stanford professor who adapted Binet’s test for American school children. • The Stanford-Binet test is widely used today.

7. Origins of Intelligence Testing • William Stern: German psychologist who created the IQ. Mental age Chronological age IQ= x 100 • A child with a mental age of 10 and a chronological age of 8: • Thus the average IQ is 100. 10 8 IQ= = 125 x 100

8. Origins of Intelligence Testing • Terman believed in eugenics and testing was a way to curb the production of “feeble-minded” children. • Eugenics: 19th century movement that proposed measuring human traits and using the results to encourage only smart and fit people to reproduce.

9. Origins of Intelligence Testing • The U.S. government curbed immigration using IQ tests to stop those less intelligent from coming to America. • Thus one major drawback of testing is labeling children as inferior, slow, or unfit. • Prejudice can come from not just skin color, but from intelligence.

10. Modern Tests of Intelligence • Aptitude: the capacity to learn. • Aptitude tests: a test designed to predict a person’s future performance. • Ex. ACT (college readiness), driver’s test (driving ability), Selective enrollment test (HS), etc. • Scores on the SAT and IQ tests has a +.82 correlation.

11. SAT and IQ Correlation

12. Modern Tests of Intelligence • Achievement tests: a test designed to assess what a person has learned. • Ex. Tests, quizzes, AP Exam, etc. • Wechsler Adult Intelligence Scale (WAIS): most widely used intelligence test today. • Wechsler Intelligence Scale for Children (WISC): intelligence test for children.

13. Test Construction • Psychological tests must meet 3 criteria to be accepted: standardized, reliable, and valid. • Standardization: give test to a representative sample AND assure that the test is both administered and scored the same for everyone. • It defines what the score you get means!

14. Test Construction • Normal Curve: a bell shaped curve in which most scores fall near the average and fewer scores are at the extremes.

15. Test Construction • Reliability: the extent to which a test yields consistent results. • Repeat the test to see if, over time, you get the same results. • Methods of measurement include test-retest(use same test), split-half (odd-even halves), and alternate form(different forms of same test).

16. Test Construction • Validity: what the test is supposed to measure or predict. • Content Validity: measures a particular behavior or trait. • Driving test measures driving ability. • Predictive Validity: able to predict future achievement. • ACT must be able to predict college readiness or its not valid.

17. Extremes of Intelligence • No real predictors for intelligence among babies up to 3 years of age. • Beginning at age 4, intelligence tests begin predicting adult scores. • At age 7, intelligence scores stabilize.

18. Extremes of Intelligence • A valid test divides people into two extreme groups: mentally retarded (IQ<70) and gifted (IQ>135).

19. Extremes of Intelligence • Mental retardation: low test score and difficulty living independently.

20. Extremes of Intelligence • Gifted children makes up 3 – 5% of the population. • They are sometimes more isolated, introverted, and in their own worlds, but most thrive and are successful. • High scorers tend to be healthy, well adjusted, and academically successful.