There are several theories about the nature of intelligence. Some psychologists believe there is a general intelligence factor, while others argue there are different types of intelligence, such as fluid intelligence and crystallized intelligence. Intelligence can be measured through IQ tests, but the concept of IQ and what it measures is debated. Factors like genes, environment, education and culture all likely influence a person's intelligence, but their relative impacts are still being studied.

2. What is intelligence? Think of the smartest people you know. What makes you think they are intelligent?

3. The World’s Smartest: Potential and Pitfalls Child Genius World’s Smartest Man

4. Intelligence What is intelligence? Are there different types of intelligence? If so, how many? Can intelligence be measured? Not all psychologists agree on the answers to these important questions

5. What Is IQ? IQ: Intelligence Quotient Score on an intelligence test Meaning has changed over time; also, how mutable it is and origins of between group differences.

6. Intelligence Testing: History Alfred Binet and Theodore Simon Developed first intelligence test (1904-1911) Identify students who need extra help Test many normal children at each age Compare individual’s score to “normal” scores Mental age Chronological age

7. Intelligence Testing: History Lewis Terman (Stanford University) Developed American version of the Binet-Simon test, called the Stanford-Binet test, for ages 2 to adult David Wechsler Wechsler Adult Intelligence Scale (WAIS) Wechsler Intelligence Scale for Children (WISC) Performance and verbal subtests

8. Wechsler Adult Intelligence Scale

9. Calculating IQ William Stern Problem: people don’t get stupider with age Modern approach Compare individual to standardized sample IQ = mental age chronological age x 100

10. The Normal Curve Population Norming Mean Standard deviation

11. Reliability and Validity A good test must be valid and reliable Reliability Test produces consistent results Validity Test measures what it is supposed to The WAIS-III is highly reliable, but is it a valid measure of intelligence?

12. IQ and Achievement IQ tends to be related to achievement High school and college grades Job prestige and salary Marital stability However, IQ accounts for only a small amount of the variation in job success Correlation is not causation Motivation, education, culture are important

13. One Intelligence or Many? Charles Spearman g : general factor s : specific factors Intelligence depends mostly on g Factor analysis Louis Thurstone Separate primary mental abilities Examples: verbal comprehension and spatial visualization

14. One Intelligence or Many? Raymond Cattell and John Horn Crystallized intelligence Fluid intelligence Aging Crystallized intelligence doesn’t suffer Fluid intelligence tends to decrease Different aging effects support the distinction

15. One Intelligence or Many? Carroll’s three-stratum model Top strata is g , general intelligence Second strata includes fluid and crystallized intelligence with 6 other broad abilities Third strata includes 69 specific abilities

16. Emotional Intelligence (EI) Knowing your emotions Managing your feelings Self-motivation Recognizing others’ emotions Handling relationships Women tend to have higher EI than men

17. Multiple Intelligences Howard Gardner (8 or 9 forms of intelligence) 1) Linguistic intelligence: The ability to use language well. 2) Spatial intelligence: The ability to reason well about spatial relations. 3) Musical intelligence: The ability to compose and understand music. 4) Logical-mathematical intelligence: The ability to manipulate abstract symbols. 5) Bodily-kinesthetic intelligence: The ability to plan and understand sequences of movements. 6) Intrapersonal intelligence: The ability to understand oneself. 7) Interpersonal intelligence: The ability to understand other people and social interactions. 8) Naturalist intelligence: The ability to observe carefully. 9) Existential intelligence: The ability to address “the big questions” about existence.

18. Brain Size and Intelligence Is bigger always better? Depends more on size of crucial brain areas Females tend to have smaller brains but equal IQs Correlation between size and intelligence is small Correlation is not causation

19. IQ and Speed of Processing Is IQ correlated with speed of information processing? Mixed results Many IQ subscales are time, so it is not surprising that mental processing speed would be related to IQ Measures of neural conduction are only weakly related to intelligence

20. Working Memory and IQ IQ is correlated with working memory Many IQ subscales are involve memory, so it is not surprising that mental processing speed would be related to IQ

21. IQ: Genes and Environment Adoption studies Correlation of IQs for identical twins raised apart is higher than that for fraternal twins and nontwin siblings raised together An adopted child’s IQ correlates higher with the biological mother’s IQ than with the adoptive mother’s IQ Strong evidence of the link between genes and IQ

22. IQ: Genes and Environment Effects of environment Stoolmiller (1999) estimated the effects of the environment on IQ to be 57% Microenvironment Reaction range

23. Group Differences in IQ Within-group versus between-group differences Genetics accounts for 72% of IQ variation in affluent environments Genetics accounts for 15% of IQ variation in impoverished environments Race differences: Why? Test bias Environmental differences Microenvironments Sex differences

24. Boosting IQ The Flynn effect Average IQ increases 3 points every 10 years Explanations? Daily life is more challenging Nutrition is better Reasoning ability stressed by IQ tests has gotten better, not IQ itself

25. The Pygmalion Effect Rosenthal & Jacobson “ Harvard Test of Inflected Acquisition” Random selection of children Self-fulfilling prophecy

26. Educational Programs and IQ Head Start and similar projects Most show only short-term IQ gains Most gains evaporate over time Abecedarian Project Intellectual, medical, and nutritional enrichment 5 years before kindergarten Long-term 5-point IQ boost

27. Mental Retardation IQ less than 70 4-7 million Americans Islands of excellence Kim Peek

28. Mental Retardation Genetic influences Down syndrome Fragile X syndrome Autism Environmental influences Fetal alcohol syndrome Childhood diseases Exposure to environmental toxins Inadequate medical care

29. The Gifted IQ of 150-180 Prodigies