Theories of Intelligence

Ability to learn from experience, solve problems, and apply knowledge

in new situations

Theorists

• Charles Spearman - psychometrics– General intelligence (g) factor

– Factor analysis – cluster test items together when scoring

• Thurstone – further evidence for g factor– If person did well on one

type of intelligence, they did well on other factors also

Gardner’s Multiple Intelligences

1. Linguistic2. Logical-mathematical3. Spatial4. Musical5. Body-kinesthetic6. Intrapersonal7. Interpersonal8. Naturalist9. Existential?

Savant Syndrome

Person with otherwise limited mental ability has an exceptional skill (computation, drawing)

Sternberg’s Triarchic Theory

• Analytical

“Book Smarts”

• Creative • Practical

“Street smarts”

Goleman’s Emotional Intelligence (EQ)Ability to perceive, understand, manage, and

use emotions

Component Description

Perceive emotionRecognize emotions in

faces, music and stories

Understand emotion

Predict emotions, how they change and blend

Manage emotionExpress emotions in different situations

Use emotionUtilize emotions to adapt or

be creative

Brain Size and IntelligenceIs there a link?

• Small +.15 correlation between head size and intelligence scores (relative to body size).

• Using an MRI they found +.33 correlation with brain size and IQ score.

• Higher intelligence = more gray matter?

Brain Function & Intelligence• Perceptual processing speed correlated with

intelligence scores (+.3 to +.5)

Stimulus Mask

Question: Long side on left or right?

Francis Galton & Intelligence

• Believed it was possible to measure “natural ability” & encourage those of high ability to mate with one another

• Found that intellectual strengths did not correlate with muscular power, body proportions, or sensory acuity

Assessing Intelligence

• Alfred Binet – Assumed all children follow

same course of intellectualdevelopment but some develop quicker

– Mental age = level of performance associated w/chronological age

• Lewis Terman & Innate IQ– Intelligence tests measured

only innate ability where environmental factors were insignificant

• Stanford-Binet Test (created by Lewis Terman) = widely used American version of Binet’s original test

IQ = mental age x 100

chronological age

Types of TestsAptitude

• Measure ability or potential.

Achievement• Tests that measure

what you have learned.

Wechsler Scales• Verbal tasks & performance tasks• WAIS (adults)• WISC (children)• Based on normal distribution

Normal Distribution

Standardization = defining meaningful scores by comparison with performance of pretested group

The Flynn Effect

• Average IQ scores have risen over time –why? Better nutrition? Education? Opportunities? Parent investment?

Test Construction• Reliability - consistent scores when test is re-taken

– Test-retest reliability

– Split-half reliability

Most do have reliability

• Validity – does it measure what it intends to measure?– Content validity

– Predictive validity

• Intelligence tests correlate w/job success

Most have some validity, but debatable

Stability v. Change• Observation & intelligence tests before age 3 only modestly predict

future aptitudes– By age 3-4 begins to predict adolescent & adult scores

– Most of the higher scoring had begun reading by age 4, age 5

• Consistency of scores over time increases with age of child

• Longitudinal study – 1932-1997 (Deary et al) – correlation for Scottish children 11.5 to 77 years of age was +.66

• Depends on Crystallized or Fluid intelligence

Intelligence for factual information (knowledge from reading books, etc.) – Stays same or increases w/age

Intelligence for reasoning, analyzing, problem-solving – decreases with old age

Extremes of IntelligenceA valid intelligence test divides two groups of people into two extremes: the mentally retarded (IQ 70) and individuals with high

intelligence (IQ 135). These two groups are significantly different.

Extremes of Intelligence – Low Extreme

• Intellectual disability – condition of limited mental ability, IQ score of 70 or below, difficulty adapting to demands of life, varies from mild to profound

• Down syndrome – intellectual disability & associated physical disorders caused by extra copy of chromosome 21

Extremes of Intelligence – Low Extreme

High Intelligence

Contrary to popular belief, people with high intelligence test scores tend to be healthy,

well adjusted, and unusually successful academically.

Is being gifted due to a self-fulfilling prophecy?

Should there be different placement based on IQ levels?

Genetic Influences on Intelligence

Identical twins have similar IQ scores

IQ more resembles biological parents than adopted parents(but difference decreases w/age)

Heritability

• Extent to which variation among individuals can be attributed to genetic factors

• Heritability for IQ is 50% (difference between Person A and Person B is 50% likely due to genes, 50% attributed to environment

Genetic Influences on Intelligence

Environmental Influences The Schooling Effect – schooling & intelligence interact, and both enhance later success Yet, schooling is not the ONLY factor!

Mozart Effect? • Does listening to classical music as a child increase

later IQ scores? • Possible temporary increase in cognitive skills, BUT…• Studies have shown no statistically significant effect

Gender & Ethnic Differences in Intelligence

Gender Differences• Girls

– Better spellers

– Better verbal fluency & memory for words

– More sensitive to taste, touch, odor

– Better emotion detectors

– Good at math computation

• Boys– Better at math

problem-solving

– Spatial aptitude

– Greater male variability in test scores

Gender Similarities and Differences

There are seven ways in which males and females differ in various abilities.

1. Girls are better spellers

2. Girls are verbally fluent and have large vocabularies

3. Girls are better at locating objects

4. Girls are more sensitive to touch, taste, and color

5. Boys outnumber girls in counts of underachievement

6. Boys outperform girls at math problem solving, but under perform at math computation

7. Women detect emotions more easily than men do

Ethnic Similarities & Differences

• High-scoring groups = higher levels of education & income

• Race is not a neatly defined biological category• Better-fed, better-educated, more test-prepared

population exceeds that of 1930’s popul.• White & Black infants scored equally well on

infant intelligence measure• Whites & Blacks exhibit similar info-processing

skill

Bias in Intelligence Tests• Genetically disposed race differences in intelligence? • Socially influenced race differences in intelligence?• Race different in test scores, but tests are inappropriate or

biased• Two meanings of bias =

– Biased if test detects innate differences & also performance differences caused by cultural experiences

– Scientific meaning (whether it predicts future behavior)

Bias in Intelligence Tests

• Stereotype threat – self-confirming concern that one will be evaluated based on a negative stereotype.

• Expectation that one’s ethnicity or gender typically does not do well causes anxiety & affect performance