1. Module 13
Intelligence

2. DEFINING INTELLIGENCE
Two-factor theory
Psychometric approach
measures or quantifies cognitive abilities or factors that are thought to be involved in intellectual performance
Two-factor theory,
by Charles Spearman
says that intelligence has two factors:
general mental ability factor “g”
represents what different cognitive tasks have in common
specific factors which include specific mental abilities such as mathematical, mechanical, or verbal skills “s”

3. DEFINING INTELLIGENCE (CONT.)
Multiple-intelligence theory
Gardner’s multiple-intelligence theory
Howard Gardner
instead of one kind of general intelligence, there are at least seven different kinds which include:
verbal intelligence
musical intelligence
logical mathematical intelligence
spatial intelligence
body movement intelligence (to understand oneself)
intelligence to understand others

4. DEFINING INTELLIGENCE (CONT.)
Triarchic theory
Robert Sternberg
says that intelligence can be divided into three different kinds of reasoning processes
uses analytical or logical thinking skills that are measured by traditional intelligence tests
uses problem-solving skills that require creative thinking and the ability to learn form experience
uses practical thinking skills that help a person adjust to, and cope with, his or her sociocultural environment

5. MEASURING INELLIGENCE
Earlier attempts to measure intelligence
head size and intelligence
Francis Galton
noticed that intelligent people often had intelligent relatives and concluded that intelligence was, to a large extent, biological or inherited
low correlation between head size and intelligence
using head size as a measure of intelligence was abandoned in favor of using skull or brain size

6. p284 BRAIN SIZE

7. MEASURING INELLIGENCE
Earlier attempts to measure intelligence
Brain size and intelligence
Paul Broca
claimed there was a relationship between size of brain and intelligence
larger brains indicating more intelligence
later reanalysis of Broca’s data indicted that measures of brain size proved to be unreliable and poorly correlated with intelligence

8. MEASURING INTELLIGENCE (CONT.)
Earlier attempts to measure intelligence
brain size and achievement
enormous variation in brain size and achievement
brain size, sex differences, and intelligence
women’s brains weigh about 10% less than men’s
little or no difference in intelligence between men and women
larger size of men’s brains does not result in higher IQs

9. MEASURING INTELLIGENCE (CONT.)
Binet’s breakthrough
Alfred Binet
believed that intelligence was a collection of mental abilities and that the best way to assess intelligence was to measure a person’s ability to perform cognitive tasks, such as understanding the meanings of words or being able to follow directions
Binet-Simon Intelligence Scale
contained items arranged in order of increasing difficulty
measured vocabulary, memory, common knowledge, and other cognitive abilities

10. MEASURING INTELLIGENCE (CONT.)
Binet’s breakthrough
mental age: measure of intelligence
Binet and Simon revised their intelligence scale to solve several problems in their original scale
mental age
method of estimating a child’s intellectual progeress by comparing the child’s score on an intelligence test to the scores of average children of the same age

11. MEASURING INTELLIGENCE (CONT.)
Formula for IQ
Intelligence quotient
computed by dividing a child’s mental age (MA), as measured in an intelligence test, by the child’s chronological age (CA) and multiplying the result by 100

12. p285 FORMULA FOR IQ

13. MEASURING INTELLIGENCE (CONT.)
Wechsler Intelligence Scale
most widely used IQ tests
Wechsler Adult Intelligence Scale (WAIS-III), ages 16 and older
Wechsler Intelligence Scale for Children (WISC-III) for children ages 3-16
both have items that are organized into various subtests.
verbal section
performance section
verbal and performance combined give a single IQ

14. MEASURING INTELLIGENCE (CONT.)
Two characteristics of tests
Validity
means that the test measures what it is supposed to measure
Reliability
refers to consistency: score on a test at one point in time should be similar to the score obtained by the same person on a similar test at a later point in time

15. DISTRIBUTION & USE OF IQ SCORES
Normal distribution of IQ scores
Normal distribution
refers to a statistical arrangement of scores so that they resemble the shape of a bell and, thus, is said to be a bell-shaped curve

16. p288 IQ CHART

17. DISTRIBUTION & USE OF IQ SCORES (CONT.)
Mental retardation: IQ scores
Mental retardation
refers to a substantial limitation in present functioning that is characterized by significantly subaverage intellectual functioning, along with related limitations in two of ten areas, including communication, self-care, home living, social skills, and safety.
borderline mentally retarded: IQs from 50 to 75
mildly/moderately mentally retarded: IQs from 35 to 50
severely/profound mentally retarded: IQs from 20 to 40

18. DISTRIBUTION & USE OF IQ SCORES (CONT.)
Mental retardation: IQ scores
Causes
Organic retardation
results from genetic problems or brain damage
Cultural-familial retardation
results from a greatly impoverished environment.

19. DISTRIBUTION & USE OF IQ SCORES (CONT.)
Vast majority: IQ scores
about 95%, have scores that fall between 70 and 130
Gifted: IQ scores
Moderately gifted
usually defined by an IQ score between 130 and 150
Profoundly gifted
usually defined by an IQ score around 180 or above

20. NATURE-NURTURE QUESTION
Definitions
asks how nature-hereditary or genetic factors-interacts with nurture-environmental factors-in the development of a person’s intellectual, emotional, personal, and social abilities
Twin studies
Fraternal twins
like siblings (brothers and sisters), develop from separate eggs and 50% of their genes in common

21. NATURE-NURTURE QUESTION (CONT.)
Twin studies
Identical twins
develop from a single egg and thus have identical genes, which means that they have 100% of their genes in common
Interaction of nature and nurture
when researchers report that genetic factors influence intelligence (IQ scores)
mean that genetic factors influence cognitive abilities to varying degrees, depending on the environment

22. NATURE-NURTURE QUESTION (CONT.)
Adoption studies
children with limited social-educational opportunities and low IQs were adopted by parents who could provide increased social-educational opportunities
studies show that children with poor educational opportunities and low IQ scores can show an increase in IQ scores when they are adopted into families that provide increased educational opportunities

23. NATURE-NURTURE QUESTION (CONT.)
Interaction: nature and nurture
Heritability
number that indicates the amount or proportion of some ability, characteristic, or trait that can be attributed to genetic factors (nature)
Reaction range
indicates the extent to which traits, abilities, or IQ scores may increase or decrease as a result of interaction with environmental factors