Intelligence

What is intelligence? Varies by culture  Western cultures focus on cognitive tasks

Is “IQ” nature or nurture? IQ and genetic effects (Genetics effects IQ)

IQ partly based on heredity Identical twins reared separately have more similar IQ than fraternal twins reared together.

Is “IQ” nature or nurture? IQ and birth parents (Childrearing effects IQ)

Is IQ one general ability or several specific abilities? Factor analysis  Used to determine if intelligence is one or a cluster of traits  Clusters: verbal, mathematical, spatial, reasoning abilities General intelligence “G” factor  A general capacity that underlies all specific mental abilities

Specific types of intelligence Emotional Cognitive Unique

Emotional intelligence Ability to express, understand, and process emotions Being very empathic

Cognitive intelligence Math Reading comprehension

Unique intelligence Savant Syndrome  Incredible ability in one area Numbers, drawing, music, memory

Beginnings of intelligence testing Originally designed to measure cognitive aptitude Alfred Benet  Predicted school achievement with mental age  Eg. A 9 year old child has a mental age of 9 Lewis Terman (From Stanford University)  Created the American revision of Binet’s original intelligence test  Developed the “Stanford-Binet” IQ test

Intelligence Quotent (IQ) Mental age divided by chronological age X 100 E.g. 15 divided by 15 X 100 = divided by 8 X 100 = 125 Worked well for children but not adults Today’s IQ tests compare the person’s performance to others of his own age (100 is average)

Standardization Scores relative to a pre-tested group Based on a normal curve  The Bell shaped (normal) curve Ave. a score of intelligence test = 100

Standard intelligence tests WAIS  Wechsler Adult Intelligence Scale WISC  Wechsler Intelligence Scale for Children

Other tests Achievement tests - Measure what has been learned  Calculus test Aptitude tests - Predicting ability  A test of your capacity to learn  College entrance exams ( SAT & GRE exams)

Creating tests Validity Reliability Standardization

Validity Measuring what it is supposed to measure  Content validity College exams Driver’s license exam  Criterion validity Test compared to criterion group  (e.g. depressed patients)  Predictive Validity SAT & GRE exams

Reliability Consistent results Internal consistency  Odd v.s. even questions

Standardization Testing a group Determining scoring based on a bell curve.