Intelligence in PSY

CHAPTER 10—INTELLIGENCE

I. How Can Intelligence Be Measured?

A. Intelligence – ability to direct one’s thinking, adapt to one’s circumstance, and learn from one’s

experiences

B. The Intelligence Quotient

1. Ratio IQ – mental age divided by chronological age x 100

2. Deviation IQ – a statistic obtained by dividing a person’s test score by the average test score

of people in the same age group and then multiplying the quotient by 100

C. The Logic of Intelligence Testing

1. Measurement of intelligence requires that we generate an operational definition.

2. devise tasks whose successful completion is correlated with the consequences that intelligence

produces

3. most widely used Intelligence tests today are a revision of the Stanford-Binet test and the

Wechsler Adult Intelligence Scale (WAIS)

a. some areas tested on the WAIS include: vocabulary, similarities,

comprehension, matrix reasoning, and block design

D. The Consequences of Intelligence

1. Intelligence test scores predict a person’s academic performance, job performance, health,

wealth, attitudes, and even basic cognitive abilities.

II. Is Intelligence One Ability or Many?

A. A Hierarchy of Abilities

1. Factor Analysis – statistical technique used to explain a large number of correlations in terms

of a small number of underlying factors

a. Two-Factor Theory of Intelligence – Spearman’s view of general ability (g) and specific

skills (s)

b. Thurstone’s view of primary mental abilities: word fluency, verbal comprehension,

numerical, number, space, memory, perceptual speed, reasoning

2. A Three-Level Hierarchy – everybody’s got a piece of the truth

a. General intelligence (g) followed by middle-level abilities, followed by specific factors (s)

B. The Middle-Level Abilities

1. Data-Based Approach – look at responses to intelligence tests and construct factors from

there

a. Suggests eight independent middle-level abilities

i. Memory and learning, visual perception, auditory perception, retrieval ability, cognitive

speediness, processing speed, crystallized intelligence, and fluid intelligence

(a) Fluid Intelligence – ability to see abstract relationships and draw logical inferences

(b) Crystallized Intelligence – ability to retain and use knowledge that was acquired

through experience

2. Theory-Based Approach – look at human abilities, then construct tests from there

a. Sternberg’s Theory – Analytic, creative, and practical intelligences

b. Prodigies and savants

i. Prodigies have normal intelligence and extraordinary abilities

ii. Savants have low intelligence and extraordinary abilities

c. Emotional Intelligence – the ability to reason about emotions and to use emotions to

enhance reasoning

III. Where Does Intelligence Come From?

A. Genetic Influences on Intelligence

1. Genes exert significant impact on intelligence

a. Heritability Coefficient – estimates the percent of difference between intelligence scores

of different people that is due to genes

b. Identical twins (who have 100 percent of genes in common) tend to have very similar

intelligence

c. Fraternal twins (who have 50 percent of genes in common) have intelligence scores that

are less-strongly related

d. Shared and nonshared environments also play a role in intelligence

B. Environmental Influences on Intelligence

1. Group difference in scores

a. Test questions, test situations, or both can be biased

IV. Are Some Groups More Intelligent Than Others?

A. Differences between groups in intelligence can be attributed to environmental factors.

1. Intelligence tends to decrease over the life span and increase across generations.

a. Relative intelligence stays fairly constant across the lifespan.

b. Absolute intelligence may decline over the life span.

c. Successive generations show evidence of the Flynn effect. (intelligence test scores tend to

rise by about .3 percent each year)

V. Improving Intelligence

1. Formal education seems like an idea that is here to stay.

a. Education increases intelligence, but has less impact than we would like to believe.

2. Researchers at the frontiers of science are investigating ways to improve intelligence through the

manipulation of genes or the application of “smart drugs”.