Week 6 Group and Individual Differences in Intelligence

Question 1

What are the trends regarding age-related changes in IQ?

Answer 1

IQ is stable from 17-19, increases from 18-19 and reaches a peak between 24 and 24 years. Sharply declines after 34-44y and steadily decreases from then.

Question 2

Which aspects of intelligence are most susceptible to aging?

Answer 2

speed of processing (biggest decline), attention/ concentration and fluid reasoning.

Question 3

True or false, verbal skills and non-verbal remain stable throughout a lifespan.

Answer 3

False.

It is true that verbal skills remain stable throughout a lifespan declines (after 55).

Question 4

True or false, crystallised knowledge increases with age and fluid intelligence steadily declines from middle adulthood?

Answer 4

True

Question 5

What are the differences between cross-sectional and longitudinal studies regarding age-related changes in IQ.

Answer 5

• cross sectional studies show sharp declines in IQ over a lifespan whereas longitudinal studies show a more gradual decline

Question 6

What is a weakness of cross-sectional studies for age-related changes in IQ

Answer 6

• cross-sectionals have confounders: changes in culture & age

Question 7

What are the weaknesses of longitudinal studies for age-related changes in IQ

Answer 7

practice effects; small IQ increase on re-test (test after 8-12 months)

age-related (older ppl less increase)

College students back-to -back increased on verbal (3.1) and performance (14.2)

practice an artefact (Flynn Effect)

Selective attrition - some ppl more likely to stay in the study

Question 8

To compensate for the drawbacks of both cross-sectional and longitudinal studies, what is recconmended

Answer 8

cross sequential designs / cohort-sequential designs

(combination of two methods).

Question 9

Summarise the Seattle longitudinal study (1956)

Answer 9

• 200 participants ages 20 to late 60s. 7 years later, 26 participants remained
• 3 generations
• cross-sectional (age comparison), longitudinal (same participants)
• intervention studies included

Question 10

Summarise the findings of Seattle longitudinal study (1956)

Answer 10

• substantial generational differences: younger/ later cohorts improved inductive reasoning, verbal meaning spatial orientation. Older cohorts better number/word fluency
• individual differences: no CVD, High SES, stimulating environments, flexible personality, intellectual spouse, maintenance of high processing speeds
• cognitive training improved intellectual disability
• adults children & parents had similar IQ

Question 11

What does the Flynn Effect propose?

Answer 11

Related to population changes in IQ and it suggests that there is a general trend of increasing IQ with passing of time.

Research supports this effect but there is no evidence for why it occurs.

Question 12

What are the possible reasons for the Flynn effect occuring?

Answer 12

participant characteristics

• rising education levels
• equity of education
• increased familiarity with IQ tests

Methodological explanations

• changes in measures between different sampling periods
• changes in motivation/effort
• changes in stimulating environments

Biological explanations

• food and nutrition
• infectious diseases
• heterosis –> natural selection