Intelligence – Part 2

• Write EVERYTHING in BLUE

• You Do NOT need to write what is in BLACK

Assessing Intelligence

• Intelligence tests-method for assessing a person’s mental aptitudes & comparing them to others.

Intelligence Review

• Mental ability is the capacity to reason, remember, understand, solve problems, and make decisions.

• Western cultures indicate mental ability in terms of thought . . the pursuit of intelligence! (Intell)

Intelligence Review

• Divergent thinking is the ability to think along many paths to generate many solutions to a problem. – More than one solution to the problem

• Convergent thinking is the ability to think logically to come up with one answer

• Divergent thinking tests measure the number of different or unusual plausible responses that one can list for each item.

History of intelligence testing• Alfred Binet & Theodore Simon– Developed child’s mental age: the

chronological age typical of a given level of performance• Average 9 year old has mental age of a 9

year old (brilliant right?)

– Theorized that mental aptitude is a general capacity that shows up in various ways

– Did not try to find out WHY children were below average

History continued…

• Lewis Terman– wrote an English version of Binet’s

test, the Stanford-Binet. Terman devised the IQ, or intelligence quotient• IQ=Mental Age (MA) x100

chronological age– Most no longer do this; use mental

age relative to average performance of others of same age

History continued…

• In 1912 Henry Goddard created a test stressing English writing skills and American culture for immigration purposes.

• In 1949, Wechsler developed the modern test w/ 11 subtests. WAIS:Wechsler Adult Intelligence Scale

• Overall intelligence score + separate scores for verbal comp, perceptual organization, working memory & processing speed

History continued…

• Most people score near the middle, so that has set the?– norm

• Normal curve: symmetrical bell-shaped curve clustered around the middle (average)

Reliability- Repeat the task and get the same

results: - Stability - correlation co-efficients are = to .80 or above– Test-re-test reliability - same test

given twice w/o practice & use alternative form of original exam.

– Split half- first and second half scores should correlate.• Could compare results on odd versus

even numbered questions.

Validity

• A test may be reliable, without being valid• Validity – the degree to which a test measures

what it is supposed to measure.– What would happen if we used a inaccurate scale

or tape measure?• Would be highly reliable (consistent) but would lack

validity

Validity - continued

• Content validity – testing for the correct material– Study math, test psy????

• Construct Validity –determine whether or not a common factor can be shown to exist underlying several measurements using different observable indicators– Older people score higher on IQ exams + your test proves this remarkable

feat.• Criterion validity –the behavior that a test is designed to predict

– study Spanish I and I go to Mexico thinking I can communicate fluently. . .

– The predictive V is very low because Spanish I does not groom fluently -speaking tourists.

– i.e. SAT scores should show success in 1st year of college. . Which Validity does this measure?• CONSTRUCT

Are IQ Tests Valid & Reliable

• IQ scores lack stability in childhood, but are very reliable for teens/adult– But it is hard to assess IQ test validity because…….– Psychologists do not even agree on exactly what intell is. That is a big

point

• IQ tests assess only a few hypothesized intellectual ACTIVITIES - SOOOOO what is good about them? What do they prove?– DO predict academic success and performance in the workplace.

Norms have been established in a variety of settings!

Nature versus Nurture

• DO IQ SCORES MEASURE INNATE ABILITY?– Nature and nurture interact in affecting intell– Heredity + environment are often confounded. – Heredity strongly affects IQ scores. Identical twins (who

share identical genes), even adopted from birth by separate families, have IQ scores correlated at r = .6.

– Yet, correlations between IQ scores are higher if twins share the same home versus being raised apart.

3). IT HELPS TO HAVE AN “ENRICHED” ENVIRONMENT