1 / 46

Intelligence

Intelligence. Definition. individual differences in the ability to acquire knowledge, to think and reason effectively, and to deal adaptively with the environment (Passer & Smith). History of Intelligence Testing. Francis Galton (1822-1911) cousin of Charles Darwin

richard-jefferson
Download Presentation

Intelligence

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Intelligence

  2. Definition • individual differences in the ability to acquire knowledge, to think and reason effectively, and to deal adaptively with the environment (Passer & Smith)

  3. History of Intelligence Testing • Francis Galton (1822-1911) • cousin of Charles Darwin • advocate of hereditarianposition • Hereditary Genius • study of eminence • creates first “intelligence” tests • Alfred Binet (1857-1911) • develops test to identify those who would benefit from remediation (mental orthopedics)

  4. Mental Age (MA) • a measure of the developmental level on which a person is functioning • a person with a mental age of 8 years can successfully complete the same intellectual tasks as the average 8-year-old child • measure given by the Binet-Simon scale

  5. Age-Related Tasks From Binet’s 1911 Test • Three-Year Old should be able to • point to body parts such as eyes, nose, and mouth • repeat sentences of six syllables (e.g., The girl ran up the hill) • identify common objects in a picture

  6. Age-Related Tasks From Binet’s 1911 Test • Seven-Year Old should be able to • understand the difference between left and right • describe a picture • count the value of six coins • carry out three commands given in a sequence (e.g., clap hands, hop forward, and touch nose)

  7. Age-Related Tasks From Binet’s 1911 Test • Fifteen-Year Old should be able to • find three rhymes for a word in a minute • repeat seven digits • interpret a set of facts • repeat a 26 syllable sentence (e.g., The young gentleman helped the old woman carry her belongings up the steep staircase to her room last night)

  8. History of Intelligence Testing III. Intelligence Tests in America • Goddard • 1908 translates Simon-Binet test into English • staunch heredetarian • Terman • develops Stanford-Binet test in 1916

  9. IQ - Intelligence Quotient • originally derived by German psychologist William Stern (1914) • uses both mental age and chronological age • Bobby: CA=5 MA= 2 • Ginny: CA=15 MA= 12

  10. History of Intelligence Testing IV. Measuring Intelligence in Adults David Wechsler Wechsler’s Contributions WAIS Wechler Adult Intelligence Scale WISC Wechsler Intelligence Scale for Children (ages 5 - 15) WPPSI Wechsler Primary & Preschool Scale of Intelligence (ages 4-6)

  11. Wechsler’s Contributions (con’t) • adopts multifaceted view Verbal Intelligence Performance Intelligence

  12. Wechsler Subtests: Verbal Scale

  13. Wechsler Subtests: Performance Scale

  14. Wechsler’s Contributions (con’t) • devises concept of deviation IQ

  15. Extreme’s of IQ mental retardation • subnormal general mental ability accompanied by deficiencies in everyday living skills originating prior to age 18

  16. Extreme’s of IQ • giftedness • top 2-3% of IQ distribution typically IQ > 130

  17. Psychometric View of Intelligence Factor Analysis • Primary method used to describe intelligence structure • Correlations among many test scores are examined with the goal of discovering something about the nature of the factors that affect them • How many different factors are needed to explain the pattern of relationships among these variables?

  18. Factor Analysis Matrix Reading Numerical Visual

  19. Psychometric View of Intelligence • Spearman’s “g” • “positive manifold” in correlation matrix of various cognitive tests • uses factor analysis to analyze correlation matrix • test performance composed of two factors: • “g” – general intelligence • “s” – specific ability

  20. Psychometric View of Intelligence • Thurstone’s Primary Mental Abilities • also uses factor analysis • certain tests correlate more highly with each other

  21. Thurstone’s Primary Mental Abilities • argues for seven different mental abilities • verbal comprehension • word fluency • number • spatial relations • associative memory • perceptual speed • inductive reasoning

  22. Psychometric View of Intelligence Crystallized Intelligence(use of existing knowledge) Fluid Intelligence(solving new problems) C. Crystallized and Fluid Intelligence • Cattell (1963) / Horn (1985) General Intelligence

  23. Information Processing & Intelligence • Inspection time • How long a stimuli has to be viewed before an accurate judgment can be made • How quickly a person gives their answer is irrelevant, participants are encouraged to take their time

  24. Inspection Time and IQ • Nettlebeck & Lally (1976) • First to note the relationship • Nettlebeck (1987) • Inspection time accounts for 25% of IQ variance (r = -.5) • The higher the IQ, the less stimulus time needed to accurately inspect the stimuli

  25. Hereditary & Environmental Determinants of Intelligence • Historical Perspectives • Francis Galton/Lewis Terman • hereditarian/nature perspective • John Stuart Mill/Binet • environmental/nurture perspective • More Recent Views • Phillipe Rushton • Arthur Jensen • Leo Kamin

  26. Evidence Supporting Hereditarians’ Position • Galton’s Study of Eminence • Hereditary Genius • Twin Studies

  27. Evidence Supporting Hereditarians’ Position • Adoption Studies • Child/Natural Mother: r=0.22 • vs • Child/Adoptive Mother: r=0.15

  28. Evidence Supporting Environmentalists’ Position • Adoption Studies • child & adoptive mother: r=0.15 • siblings reared together: r=0.47 • vs • siblings reared apart: r=0.22 • fraternal twins: r=0.58 • vs • siblings r=0.43 • unrelated siblings: r=0.30

  29. Evidence Supporting Environmentalists’ Position • Altered Environments • Impoverished Environments • cultural deprivation hypothesis • 1920 English canal children • children reared in Kentucky mountains • Enriched Environments • Home-Environment Studies • Flynn-effect

  30. Interactionist View • reaction range • heredity sets limits on intelligence while environmental factors determine where individual falls

  31. Reaction Range

  32. Cultural Differences in IQ • 10-15 IQ point difference between average Caucasian and Black Americans • Possible Explanations • Jensen’s Heritability Explanation (1969) • hereditability for IQ: H = 0.80

  33. Heritability Estimates Heritability Ratio: estimate of proportion of trait variability in a population that is determined by variations in genetic inheritance where: VG = variance due to genetic differences VT = total trait variance

  34. Cultural Differences in IQ • Possible Explanations • Kamin’s Rebuttal of Jensen

  35. Cultural Differences in IQ • Possible Explanations (con’t) • Cultural Disadvantage • minority groups live in impoverished environment • Cultural Bias on IQ Tests • tests administered by whites • tests reflect white, middle-class values • tests written in “white” language

  36. Psychometrics • Psychological test • standardized measure of a sample of a person's behavior

  37. Concepts related to Standardization • Norms • Percentile Score

  38. Correlation Coefficient • r = 0.95 • index that assesses degree of linear relationship between two variables

  39. Reliability • the consistency with the test measures what it measures

  40. Ways of Assessing Reliability • test-retest • alternative forms • split-half • internal consistency • Cronbach’s a

  41. Validity • refers to the ability of a test to measure what it was designed to measure

  42. Methods of Assessing Validity • content validity • criterion-related validity • predictive validity • construct validity • convergent validity • discriminant validity

  43. last day for Research Participation is Monday December 1st. • Check your Research Participation grade – maximum 6% – on WebCT after 2:00 pm on Thursday December 4th • If you think there is an error, e-mail galder@sfu.ca by noon Friday December 5th.

  44. Psyc 102 Fall 2008 Final Exam • Thursday December 4th 12:00-14:00 • 100 multiple-choice questions • ~50% Chapters 8, 9, & 11 • ~50% Chapters 12-16 • bring SFU ID, pencil, eraser • If your last initial is between A-Q you’ll write in C9001 • If your last initial is between R-Z you’ll write in C9002

More Related