IMPORTANT: Upcoming Test• one week from today• Thursday January 29• in class, NatSci 1, at 12:00-1:50• worth 10% of course grade• 40 multiple choice questions

• Test Yourself questions give you some idea of what to expect• A few sample test questions will be posted on the web on Tuesday

Material covered:• Motivation lectures and Chapter 6 assigned FQs• Reasoning & Intelligence lectures and Chapter 10 assigned FQs

– Note: I recently removed Ch. 10, FQ10 (heritability coefficient) from the assigned FQs -- it will NOT be tested

• NOT Language and Nonverbal Communication nor associated FQs (Ch 10, FQ 37-40)

REASONING• Deductive reasoning

– Given a set of premises, draw a conclusion– series problems– syllogisms– mental models (see text)

• Inductive reasoning– See examples and make hypotheses to explain the situation/pattern– Sherlock Holmes– Errors

• representativeness overvalued (base rate undervalued)• availability bias

– number of examples encountered biases probability estimates• confirmation bias

– people try to prove rather than disprove their hypothesis

• Insight– breaking out of mental sets– avoiding functional fixedness– Kohler’s chimps had insight; apparently crows do too

Three Minute Review

INTELLIGENCE• Is there one type of intelligence?• What practical applications have IQ tests been used for?• IQ scores

– bell curve (“normal”) distribution– mean = 100– SD = 15

Test YourselfSuppose a researcher gave subjects the following type of problem:

In a group of 100 people, 70 are pilots and 30 are bookkeepers. Of that group, one man is meek, timid, and enjoys helping people. Is he more likely to be a pilot or a bookkeeper? Most subjects would answer:

A. bookkeeper, demonstrating a bias toward representativeness.

B. bookkeeper, demonstrating a prior probability bias.

C. pilot, demonstrating use of the base-rate information given.

D. pilot, demonstrating the availability bias.

E. bookkeeper, demonstrating functional fixedness

Intelligence VideoDiscovering Psychology (Zimbardo series): Testing and Intelligence

• What is the average IQ?

• What roles did the following people play in the history of intelligence testing

– Francis Galton– Alfred Binet– Lewis Terman (at Stanford)– David Wechsler

• What are the following characteristics and why are they valuable in a test?

– validity– reliability– standardization

• Why is intelligence testing so controversial? Why might intelligence tests be biased to a particular group?

• Is there only one type of “intelligence”? What types of intelligence have been proposed by modern psychologists (particularly Howard Gardner and Robert Sternberg)?

Is there one type of intelligence?

Factor analysis• developed by Spearman to tease apart

components of intelligence• are there clusters of correlations that suggest

common underlying factors?

Charles Spearman1863-1945

Factor Analysis

Coke Classic

Dr. Pepper

7-UP Ginger Ale

Coke Classic

--- .70 .65 .75

Dr. Pepper

--- --- .59 .51

7-UP --- --- --- .68

Ginger Ale

--- --- --- ---

Coke Classic

Dr. Pepper

7-UP Ginger Ale

Coke Classic

--- .70 .20 .33

Dr. Pepper

--- --- .16 .18

7-UP --- --- --- .77

Ginger Ale

--- --- --- ---

How much do you like Coke Classic?

How much do you like Dr. Pepper?

r = .70

CORRELATION

CORRELATION MATRIX

General Intelligence: Spearman’s g

• Spearman suggested that scores on each subtest were determined by two factors– g-factor (general intelligence)

• a general factor contributing to all tests

– s-factor (specific factors)• factors that are specific to a particular test (e.g.,

arithmetic vs. spatial tests)

g

What might g be?

• mental speed and working memory?– computer analogy: faster processor and more RAM– significant correlations between reaction times and IQ (r

~-.35)– neural efficiency?– mental quickness may expand capacity of working

memory

• mental self-government?– computer analogy: better operating system

Duncan’s “g-spot”

• lateral prefrontal cortex• activated by high-g

versions of multiple intelligence tests

Non-intelligence control task

Hannibal Lecter: “You see, the brain itself feels no pain, Clarice, if that concerns you. For example, Paul won't miss this little piece here, which is the, uh, part of the prefrontal lobe which they say is the seat of good manners.”

Cattell’s Two-factor theory

• Cattell suggested two main factors in intelligence

• Mental ability derived directly from previous experience.• Examples: vocabulary, information• Ability increases over the lifetime (esp. in an intellectually stimulating environment)• Less influenced by alcohol consumption and brain damage

• Ability to perceive relationships independent of previous experience• Examples: matrix reasoning, object assembly• Ability peaks around age 20-25, then declines

Cattell’s Two-factor theory

Raymond Cattell1905-1998

Correlation between Fluid & Crystallized Intelligence? r ~ .60

World’s highest IQ

George W. BushIQ: estimated at 91

World’s most powerful job

Marilyn Vos SavantIQ: 228

Writes magazine advice column “Ask Marilyn”

Not world’s highest IQ

Does IQ Count?

Estimates for other presidents: Bill Clinton 182; Jimmy Carter 176; John F. Kennedy 174; Richard Nixon 155; Ronald Reagan 105; George Bush Sr. 99

Does IQ Predict Performance?

• socioeconomic status of parents is a better predictor of achievement than by IQ (education, connections?)

• better IQ ~ better performance (r ~ 0.2 - 0.4)• prediction is better for new than experienced

employees

How to appear to have improved your IQ!!

Talking loudly, using proper English, you seem bright, but not related

Judging IQ from short videos

Speak quickly, understandably, with lots of words you seem bright, you are bright

Usin’ slang, saying “um”, being overweight you seem less bright, but not related

Judgments based on just voice more accurate

The Cynic’s View

“Intelligence is what intelligence tests test.”

Are there other types of intelligence?

Savant Stephen Wiltshire• autistic• took much effort to gain minimal language skills• could reproduce highly accurate drawings of buildings and places years after having only glanced at them• had book of his artwork published

Is IQ hereditary?:The Sereno siblings

• six siblings, all talented academic scientists• parents: artist and educator mother and

engineer and closet-scientist father• genes or environment?

Martyneuroscientist

(vision)

Paulpaleontologist

Joanlinguist

Margaretneuroscientist

(vision)

Anneneuroscientist

(vision)

Saraneuroscientist

(language)

Is IQ hereditary?

Flynn EffectIQ has increased over time

Why?• genes don’t change that rapidly• not likely to be extra schooling because more scholastic tests have

shown smallest increases• more stimulating and complex environments and societies?• better prenatal care and nutrition?

Nature vs. Nurture(or Nativism vs. Empricism)

• Are differences between people due to environmental or genetic differences?

• Misunderstanding the question– “Is a person’s intelligence due more to

genes or to environment?”– no genes = no intelligence– bad environment = little intelligence– both genes & intelligence crucial for any

trait

Which contributes more to the area of a desk top? The length of the desk or the width?

Faulty Question