Intelligence aka Cognitive Abilities

Early research zIntelligence Test ya method of assessing an individual’s mental aptitudes and comparing them to those of others, using numerical scores

Early research zMental Age ya measure of intelligence test performance devised by Binet ychronological age that most typically corresponds to a given level of performance ychild who does as well as the average 8-year-old is said to have a mental age of 8

Early research zStanford-Binet ythe widely used American revision of Binet’s original intelligence test xrevised by Terman at Stanford University

Early research zIntelligence Quotient (IQ) ydefined originally the ratio of mental age (ma) to chronological age (ca) multiplied by 100 xIQ = ma/ca x 100) yon contemporary tests it is the average performance for a given age is assigned a score of 100

What is Intelligence? zIntelligence ycapacity for goal-directed and adaptive behavior yinvolves certain abilities xprofit from experience xsolve problems xreason effectively

What is Intelligence? zIQ is a score on a test yit is not something you have zIs intelligence singular or multiple abilities? zAnd exactly what abilities are we talking about?

What is Intelligence? zDoes it relate to speed of brain processing? zAre intelligence tests culture free? zAre intelligence tests culturally biased?

Are There Multiple Intelligences? zGeneral Intelligence (g) yfactor that Spearman and others believed underlies specific mental abilities ymeasured by every task on an intelligence test

Are There Multiple Intelligences? zThurstone and others: ynumerical ability, spatial ability, memory, etc. zGardner: ymusical, kinesthetic, environmental, etc. zCattell: yfluid and crystallized intelligence zSternberg*: yanalytical ability, creativity, social intelligence y*Switzer’s personal favorite

Are There Multiple Intelligences? zThe information processing approach: yspeed of processing yattention ymetacomponents xe.g., how you decide on a problem-solving strategy, how you decide what information you need to solve a problem, etc.

Components of intellingence? zPeople who can perceive the stimulus very quickly tend to score somewhat higher on intelligence tests Stimulus Mask Question: Long side on left or right?

Components of intellingence? zSocial Intelligence ythe know-how involved in comprehending social situations and managing oneself successfully zEmotional Intelligence “EQ” zability to perceive, express, understand, and regulate emotions zcritical part of social intelligence

Components of intellingence? zCreativity ythe ability to produce novel and valuable ideas ycomponents of creativity xexpertise ximaginative thinking skills xventuresome personality xintrinsic motivation xcreative environment

The Dynamics of intelligence zFactor Analysis ystatistical procedure that identifies clusters of related items (called factors) on a test yused to identify different dimensions of performance that underlie one’s total score Savant Syndrome ycondition in which a person otherwise limited in mental ability has an amazing specific skill xcomputation xdrawing

The Dynamics of Intelligence zMental Retardation ya condition of limited mental ability yindicated by intelligence scores below 70 yproduces difficulty in adapting to the demands of life yvaries from mild to profound zDown Syndrome yretardation and associated physical disorders caused by an extra chromosome in genetic make-up

The Dynamics of Intelligence Degrees of Mental Retardation Level Typical Intelligence Scores Percentage of the Retarded Adaptation to Demands of Life Mild % May learn academic skills up to sixth-grade level. Adults may, with assistance, achieve self-supporting social and vocational skills. Moderate May progress to second-grade level. academically. Adults may contribute to their own support by labor in sheltered workshops. Severe May learn to talk and perform simple work tasks under close supervision but are generally unable to profit from vocational training. Profound Below Require constant aid and supervision.

Assessing Intelligence zAptitude Test ya test designed to predict a person’s future performance yaptitude is the capacity to learn zAchievement Test ya test designed to assess what a person has learned

Assessing Intelligence zWechsler Adult Intelligence Scale (WAIS) ymost widely used intelligence test ysubtests xverbal xperformance (nonverbal)

Assessing Intelligence- Sample Items from the WAIS From Thorndike and Hagen, 1977 VERBAL General Information Similarities Arithmetic Reasoning Vocabulary Comprehension Digit Span PERFORMANCE Picture Completion Picture Arrangement Block Design Object Assembly Digit-Symbol Substitution

Assessing Intelligence zStandardization ydefining meaningful scores by comparison with the performance of a pretested “standardization group” zNormal Curve ythe symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes ymost scores fall near the average, and fewer and fewer scores lie near the extremes

The Normal Curve Ninety-five percent of all people fall within 30 points of 100 Number of scores Wechsler intelligence score Sixty-eight percent of people score within 15 points above or below 100

Getting Smarter? “The Flynn Effect” zIntelligence test performance has been rising

Assessing Intelligence zReliability ythe extent to which a test yields consistent results yassessed by consistency of scores on: xtwo halves of the test xalternate forms of the test xretesting the same individual zValidity ythe extent to which a test measures or predicts what it is suppose to

Assessing Intelligence zContent Validity ythe extent to which a test samples the behavior that is of interest xdriving test that samples driving tasks zCriterion ybehavior (such as college grades) that a test (such as the SAT) is designed to predict ythe measure used in defining whether the test has predictive validity

Assessing Intelligence zPredictive Validity ysuccess with which a test predicts the behavior it is designed to predict yassessed by computing the correlation between test scores and the criterion behavior yalso called criterion-related validity

Assessing Intelligence zAs the range of data under consideration narrows, its predictive power diminishes. zTherefore, the predictive power of aptitude tests scores diminish as students move up the educational ladder. Greater correlation over broad range of body weights Little corre- lation within restricted range Football linemen’s success Body weight in pounds

Genetic Influences zThe most genetically similar people have the most similar scores Similarity of intelligence scores (correlation) Identical twins reared together Identical twins reared apart Fraternal twins reared together Siblings reared together Unrelated individuals reared together

Genetic Influences zHeritability ythe proportion of variation among individuals that we can attribute to genes yvariability depends on range of populations and environments studied

Nature vs. Nurture zGroup differences and environmental impact Variation within group Difference within group Poor soilFertile soil Seeds

Nature vs. Nurture: Two critically important things to remember… z1. It’s NOT Nature vs. Nurture. All important human characteristics come from a subtle and complex INTERACTION of nature & nurture (genetics & environment)

z2. Within-group variance is always bigger than between-group variance. zIn other words, the differences between people IN a group are typically larger than the differences BETWEEN groups (because the differences between groups are averages of the people in the group) Nature vs. Nurture: Two critically important things to remember…

z For example: assume that “women are better drivers than men”. That means that on the average women drive better than men. zBUT, if you’re hiring a driver for your company, you don’t want to depend on the average, you want to give each applicant a drivers test. Because in each group there are good and bad drivers. Within-group variance is bigger than between-group variance. Nature vs. Nurture: Two critically important things to remember…

Answers to our questions: zIs intelligence singular or multiple abilities? Ans: probably more than one but exact number & types of intelligence still being debated. zDoes it relate to speed of brain processing? Ans: Yes, but other things (like potentiation, myelination, neuron density etc.) also play role in intelligence.

zAre intelligence tests culture free? Ans: No. Almost impossible to make a completely culture-free tests. zAre intelligence tests culturally biased? Ans: Probably not very much. Modern test developers try very hard (and have some new nifty mathematical tools) to minimize bias. Answers to our questions: