intelligence and its measurement

1. Intelligence and Its Measurement Module 26

3. Galton on intelligence Studied family trees of eminent people Found that eminence ran in families His theory of intelligence was that bright people must have exceptional sensory acuity Developed test to measure sensory processes Dead end / sensory ability not related to success

4. Alfred Binet and IQ tests French psychologist who developed test to identify children who had subaverage intelligence Test of general mental ability/abstract reasoning (problem solving, vocabulary, memory, general knowledge, logic) Predicted school performance “Mental age” scores--performance was like that of a typical X year old. His hope was to identify children who needed extra assistance

5. Terman and the Stanford-Binet In the U.S., Terman revised Binet’s test now termed the Stanford-Binet test First to introduce the Intelligence Quotient (IQ) IQ = (mental age/chronological age)*100 Doesn’t make sense for adults Now based on your performance relative to same-age peers

6. Weschler and adult IQ First to develop intelligence tests for adults (WAIS-III) Less dependent upon verbal ability Contains both performance and verbal subscales Replaced IQ with a scoring scheme based on a normal distribution Also the WISC III and the WPPSI-III

7. Are intelligence tests accurate? What we mean is do intelligence tests measure what they are supposed to measure? All good psychological tests need three qualities: Standardization Reliability Validity

8. Standardization How does the individual’s performance compare with the performance of the population Raw scores (# correct) are converted into standardized scores that follow a distribution Normal distribution of IQ scores 100 = mean, 15 standard deviation 68% fall within ± 1sd (85-115) 95% fall within ± 2 sd (70-130) 99+% fall within ± 3 sds (55 - 145)

9. Reliability The consistency of measurement Test-retest reliability Do you get the same score each time Split-half reliability Do you get the same results on one-half of the test as on the other half.

10. Validity Does the test measure what it says it measures? Content validity Is the content of the test representative of the material it claims to measure? Criterion-related validity Can tests predict anything? Correlation of test score with another measure of the trait

11. Is there a general intellectual-ability factor? Charles Spearman argued that there is a general intelligence (called g) Performance on specific tests tends to be highly correlated Babies who orient toward new stimuli rather than old tend to perform well later Faster reaction times on a variety of tasks (neural transmission is faster overall)

12. Are there multiple intelligences? Gardner’s theory of multiple intelligence Prodigies and idiot savants Linguistic, mathematical, spatial, musical, kinesthetic, interpersonal, intrapersonal Educators and parents like it, but little evidence Sternberg’s Triarchic Theory Analytic - School smarts Creative -divergent thought, seeing connections Practical - street smarts, adaptive skills