34 Age differences in intelligence

Question 1

How are stability and change defined in intelligence testing?

Answer 1

Stability - consistency in the rank-order of people

Change - difference in the absolute level of a trait

Question 2

Are intelligence scores stable over time?

Answer 2

Yeah, pretty much. r = .66 in the Scottish Mental Survey.

Question 3

How do scores on the infant novel object habituation test correlate with IQ?

Answer 3

Children who take longer to grow bored of a novel object have lower IQs.

Question 4

Is IQ stable among young children?

Answer 4

Actually, no, it’s the exception. Because of rapid development before 6-8 years old, IQ at this age is less predictive of IQ later.

Question 5

What explains the massive decrease of IQ across age groups in cross-sectional studies?

Answer 5

Cohort effects. In 1970 only 20% of people finished high school. Today it’s 60%.

Question 6

What is the size of the Flynn Effect on average?

Answer 6

3 IQ points per decade.

Question 7

For which groups are cohort effects the largest?

Answer 7

There is evidence that cohort effects are larger for those who grew up without technology (born in 1920s and 1930s)

Question 8

Does cross-sectional research overestimate or underestimate cognitive decline?

Answer 8

It overestimates cognitive decline.

Question 9

How might longitudinal data underestimate cognitive decline?

Answer 9

• Because Pps get practice at tests
• Those you can follow up are likely to be high IQ
• Selective attrition - those who die more likely to be low IQ

Question 10

What can old people offer cognitively to the workforce?

Answer 10

Domain-specific knowledge and expertise, which increase over the lifetime. Young people need raw reasoning because they don’t know the answer through experience.