Myers’ PSYCHOLOGY (5th Ed) Chapter 11 Intelligence James A. McCubbin, PhD Clemson University Worth Publishers

Origins of Intelligence Intelligence Test a method of assessing an individual’s mental aptitudes and comparing them to those of others, using numerical scores

Origins of Intelligence Mental Age a measure of intelligence test performance devised by Binet chronological age that most typically corresponds to a given level of performance child who does as well as the average 8-year-old is said to have a mental age of 8

Origins of Intelligence Stanford-Binet the widely used American revision of Binet’s original intelligence test revised by Terman at Stanford University

Origins of Intelligence Intelligence Quotient (IQ) defined originally the ratio of mental age (ma) to chronological age (ca) multiplied by 100 IQ = ma/ca x 100) on contemporary tests it is the average performance for a given age is assigned a score of 100

What is Intelligence? Intelligence capacity for goal-directed and adaptive behavior involves certain abilities profit from experience solve problems reason effectively

What is Intelligence? IQ is a score on a test it is not something you have Is intelligence singular or multiple abilities? Does it relate to speed of brain processing?

Intelligence Is intelligence culturally defined? Are intelligence tests culture free?

Are There Multiple Intelligences? Factor Analysis statistical procedure that identifies clusters of related items (called factors) on a test used to identify different dimensions of performance that underlie one’s total score General Intelligence (g) factor that Spearman and others believed underlies specific mental abilities measured by every task on an intelligence test

Are There Multiple Intelligences? Savant Syndrome condition in which a person otherwise limited in mental ability has an amazing specific skill computation drawing

Are There Multiple Intelligences? Social Intelligence the know-how involved in comprehending social situations and managing oneself successfully Emotional Intelligence ability to perceive, express, understand, and regulate emotions critical part of social intelligence

Brain Function and Intelligence People who can perceive the stimulus very quickly tend to score somewhat higher on intelligence tests Stimulus Mask Question: Long side on left or right?

Assessing Intelligence Aptitude Test a test designed to predict a person’s future performance aptitude is the capacity to learn Achievement Test a test designed to assess what a person has learned

Assessing Intelligence Wechsler Adult Intelligence Scale (WAIS) most widely used intelligence test subtests verbal performance (nonverbal) Wechsler Intelligence Scale for Children (WISC) similar to WAIS, but for school children

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 Standardization defining meaningful scores by comparison with the performance of a pretested “standardization group” Normal Curve the symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes most scores fall near the average, and fewer and fewer scores lie near the extremes

The Normal Curve Number of scores 55 70 85 100 115 130 145 Ninety-five percent of all people fall within 30 points of 100 Number of scores 55 70 85 100 115 130 145 Wechsler intelligence score Sixty-eight percent of people score within 15 points above or below 100

Getting Smarter? Intelligence test performance has been rising

Assessing Intelligence Reliability the extent to which a test yields consistent results assessed by consistency of scores on: two halves of the test alternate forms of the test retesting the same individual Validity the extent to which a test measures or predicts what it is suppose to

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

Assessing Intelligence Predictive Validity success with which a test predicts the behavior it is designed to predict assessed by computing the correlation between test scores and the criterion behavior also called criterion-related validity

Assessing Intelligence Greater correlation over broad range of body weights 10 9 8 7 6 5 4 3 2 1 Little corre- lation within restricted range Football linemen’s success Body weight in pounds 180 250 290 As the range of data under consideration narrows, its predictive power diminishes. Therefore, the predictive power of aptitude tests scores diminish as students move up the educational ladder.

The Dynamics of Intelligence Mental Retardation a condition of limited mental ability indicated by intelligence scores below 70 produces difficulty in adapting to the demands of life varies from mild to profound

The Dynamics of Intelligence Down syndrome retardation 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 50-70 85% May learn academic skills up to sixth-grade level. Adults may, with assistance, achieve self-supporting social and vocational skills. Moderate 35-49 10 May progress to second-grade level. academically. Adults may contribute to their own support by labor in sheltered workshops. Severe 20-34 3-4 May learn to talk and perform simple work tasks under close supervision but are generally unable to profit from vocational training. Profound Below 20 1-2 Require constant aid and supervision.

The Dynamics of Intelligence Creativity the ability to produce novel and valuable ideas components of creativity expertise imaginative thinking skills venturesome personality intrinsic motivation creative environment

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

Genetic Influences Heritability Similarity of intelligence scores (correlation) Adopted children and biological parents adoptive Heritability the proportion of variation among individuals that we can attribute to genes variability depends on range of populations and environments studied

Variation within group Difference within group Genetic Influences Group differences and environmental impact Variation within group Difference within group Poor soil Fertile soil Seeds

Genetic Influences The Mental Rotation Test of Spatial Abilities Which two circles contains configuration of blocks identical to the one in the circle at left? Standard Responses