• Second exam is Nov. 1st, one week from today.

What is intelligence?

• Sam & Sarah
• Kpelle Tribe
• meat, knife, milk, bowl

What is intelligence?

• 1921 Symposium:
• the capacity to learn from experience
• the ability to adapt to the surrounding environment
• 1986 Survey:
• learning and adapting
• ability to understand and to control mental processes
• culture dependent

What is intelligence?

• Wechsler
• Intelligence is a global capacity to act purposively, to think rationally, and to deal effectively with the environment.

Theories of Intelligence

• Psychometric theories
• Cognitive Theories
• Systems Theories

Psychometric Theories

• Seek to identify intellectual abilities and to determine how they are related to each other.
• Rely on "individual differences" and correlations between ability tests.

Spearman's Theory

• Two kinds of factors, general and specific.
• General factor, g, underlies all mental activity.
• Specific factors are relevant to particular tasks.

Thurstone's Theory

• Seven Primary Abilities:
• Verbal Comprehension
• Number
• Memory
• Perceptual Speed
• Space
• Verbal Fluency
• Inductive Reasoning

Problems with Psychometric Theories

• Number of factors is determined more by how data are analyzed than by the data themselves.
• Psychometric theories are not informative about the cognitive processes responsible for intelligent behavior.
• Incomplete, not necessarily incorrect.

Cognitive Theories

• Seek to identify and to understand the mental processes responsible for intelligent behavior.
• Example:

Types of Mental Processes

• Performance processes
• translate sensory inputs into mental representations
• transform mental representations
• translate mental representations into responses
• Planning processes
• "Executive" processes responsible for planning and evaluation.

Findings

• Higher intelligence is usually associated with faster execution of performance processes.
• But more intelligent people spend more time on planning processes.

Problems with Cognitive Theories

• Too narrowly focused on analytical abilities.

Systems Theories

• Gardner's Multiple Intelligences Theory
• Sternberg's Triarchic Theory

Triarchic Theory

• Analytical intelligence
• analyzing, comparing, evaluating
• Creative intelligence
• creating, inventing, designing
• Practical intelligence
• applying, using

Heritability of Intelligence

• There is no doubt that differences in intelligence result from both heredity and environment.
• Question is: What are the relative weights?

Twin Studies

• Identical twins share 100% of genes.
• Fraternal twins and normal siblings share, on the average, 50% of genes.
• Behavior of identical twins can be compared to that of fraternal twins and siblings.
• Particularly informative when researchers can find twins who were reared together and twins who were reared in separate families.

Heritability of Intelligence

• Estimates of the heritability of intelligence average around 50%.
• This means that approximately half of the variability in intelligence in a population is determined by genes.
• It also implies, of course, that half of the variability in intelligence in a population is not determined by genes!

Interaction of Nature and Nurture

• Between and within group variation.
• Reaction range.

Interaction of Nature and Nurture

• In many ways, the debate assumes that intelligence is fixed, and not malleable.
• Immigrant populations
• Less than 100 years ago, first generation Italian-American children had a median IQ of 87 (below average).
• Subsequent generations show average to above average IQ.

Improving Intelligence

• Children in Head Start are, by midadolescence, a full grade ahead of matched controls who did not participate.
• Several factors in preschool home environment linked to higher IQ scores, including responsivity, involvement, avoidance of restriction, organization, appropriate play materials, and variety.

Motives, Beliefs, & Intelligence

• Termin's "Termites"
• Study since 1921 of 1528 people with IQs in top 1%.
• 100 most successful men differed from 100 least successful men in motivation.

Mathematics Achievement

• 1980: On computations and word problems, lowest-scoring Beijing schools were better than top Chicago schools.
• 1990: Only 4% of Chinese children and 10% of Japanese children were scoring as low as the AVERAGE American child.
• Chinese had worse facilities and larger classes.
• American parents better off financially, and better educated.

Beliefs and Expectations

• Beliefs about intelligence
• Talent vs. hard work
• Standards
• American parents satisfied with scores barely above average; Chinese & Japanese parents only satisfied with very high scores.

Beliefs and Expectations

• Conflicts & stress
• American students expected to be "well-rounded" (after school jobs, sports, etc.); Asian children expected to devote themselves to their studies.
• Values
• American children did not value education as much as Asian children.

Moral

• It's not just what you've got that counts, but what you do with it.

Summary

• What is intelligence?
• Theories of intelligence
• Heritability of intelligence
• Improving intelligence
• Motives, Beliefs, and Intelligence