Intelligence Intelligence The global capacity to think rationally

Intelligence

Intelligence • The global capacity to think rationally, act purposefully and deal effectively with the environment • Radical Ideas: – Can intelligence be measured? – Do intelligence tests measure cultural differences? – Does heredity or environment play a part in difference of intelligence

Development of Intelligence Tests • Alfred Binet – France Commissioned to identify children who may need special help in school – Devised a series of tests to measure different mental abilities- focused on memory, attention, ability to understand similarities and differences – Brighter children answered like older children and less capable answered like younger children – Binet developed the idea of a mental age which may be different from the child’s chronological age – His tests became the basis for modern intelligence tests

Binet’s Beliefs • He did not believe that he was measuring inborn intelligence or permanent level of intelligence • Believed intelligence was too complex to describe with a single number • Refused to rank “normal” children on basis of scores-only wanted to identify children who would need special help • Recognized individual factors might affect a child’s scores –motivation- and that score could change

Development of Stanford-Binet Intelligence Test • Lewis Terman took Binet’s intelligence test and did exactly what Binet didn’t want to do: Put a numerical measure on inherited intelligence • These scores expressed in a single number called intelligence quotient or (IQ) • IQ= Mental Age X 100 Chronological Age

Group Intelligence Testing • Emerged during WWI when US needed to screen recruits to determine level of rank • From this it was adopted for civilian usedesigned to test everyone- school children, prisoners, and immigrants • Terman did a study on school children with genius IQ’s and followed them using a longitudinal study

Negatives of Group Intelligence Testing • Terman and others became convinced that IQ was important to one’s success in different professions • Tried to identify min. IQ needed for certain professions and insisted that employers should test applicants for those jobs

Principles of Test Construction • Types of tests that measure intelligence of mental ability – Achievement- designed to measure a person’s level of knowledge, skill of accomplishment • Ex. Stanford Achievement, ITBS, California Achievement Test (CAT), ACTs – Aptitude- Designed to assess a person’s capacity to benefit from education or training- tests your ability learn certain types of information or perform certain skills • SATs

Three Requirements for Test Design • 1. Standardization- test is given to a large number of subjects who are representative of the group for whom the test is designed – Subjects take same test under uniform conditions – Scores of this group establish the norms of standards against which an individual score is compared and interpreted – Norms follow a pattern of individual differences called the normal distribution- bell shaped curve where most scores cluster around the average score

3 Requirements Continued • 2. Reliability- test must consistently produce similar scores on different occasions – Can do this by giving two similar but not identical versions of the test at different times • 3. Validity- test measures what it is supposed to measure – Ex- test measures mechanical aptitudecompare test scores with the degree of success that people have in jobs with mechanical skills

Wechsler Test of Intelligence • Specifically designed for adults rather than children – Provided scores on 11 subsets measuring different abilities: Verbal scores, vocabulary, comprehension, knowledge of general info/other verbal tasks – Performance score: nonverbal tests such as identifying missing parts, arranging pictures to tell a story, arranging blocks to match a pattern

Wechsler Test of Intelligence • Profile of an individual’s strengths and weakness-if low scores on some tests and high scores on other could indicate a learning disability • Now the most commonly administered intelligence test