Varieties of Intelligence

• Evidence from Brain Damage and Cases of Unusual Development

• An Ecological Perspective on Intelligence

How People Reason and Solve Problems

• Inductive Reasoning and Biases in It• The Concrete Nature of Deductive

Reasoning

• Some Strategies for Solving Problems: Elements of Insight

How People Reason and Solve Problems

• Inductive Reasoning: Biases – representativeness– base-rate fallacy– availability bias– confirmation bias

Representativeness• Linda is 31, single, outspoken, very bright. As a

student she majored in philosophy, was deeply concerned with discrimination and other social issues and participated in antinuclear demonstrations. Which statement is more likely?

• Linda is a bank teller• Linda is a bank-teller and active in the feminist

movement

Confirmation Bias• You serve on a jury on a custody case

following a messy divorce. Given the complicated facts of the case you decide to base your decision on the following few observations.

• To which parent would you award sole custody of the child?

• Which parent would you deny custody of the child?

• Parent A: average job and income, average health, average working hours, reasonable rapport with the child, relatively stable social life

• Parent B: above average income, minor health problems, lots of work related travel, very close relationship with child, extremely active social life

Roles of Language in Thought

• Thinking in Different Languages

• Effects of Wording on Thinking Within a Language: Double-Speak

The Nature-Nurture Debate Concerning IQ

• IQ Differences Among Individuals Within a Cultural Group

• IQ Differences Between Cultural Groups

Heritability

• Misconception:

“How much of a person’s intelligence is due to genes, how much to the environment??

How much of the area of a rectangle is due to its height how much to its width??

In each group, how much of the differences in area is due to differences in height vs width?Group A? Group B?

Heritability• “How much of a person’s intelligence is due

to genes, how much to the environment??

• Within a group, how much of the differences in intelligence is caused by genes vs environment? Group A: 2 identical twins

Group B: 2 adopted siblings

Heritability• h2 = variance due to genes

total variance• = variance due to genes var.

due to genes + var. due to environment

• increase genetic variance/ environmental variance. Result?

• environmentality?

Heritability• In groups studied: h2=0.8

• Problem: group was culturally homogenous

• Higher h2 than would be found in culturally diverse group

• High within group-heritability does not mean high between-group heritability

•Same genetically diverse seed mix on Field 1 and 2•Each field is uniform•Reason for differences in plant size within a field?

•Field 1: H2=0.8•Average difference: F1/ F2:

3 inches

•Reason for differences in average plant size betweenfields?

Evidence for environmental cause for Black/ White IQ differences

• No correlation between IQ and degree of African ancestry

• matched environment tends to eliminate difference (eg: children of servicemen in Germany

• IQ difference similar to Buraku/Majority difference in Japan: difference gone when Buraku move to states

Effect of environment on IQ