Nature and Nurture of Cognitive Development

Question 1

What is cognitive development?

Answer 1

General cognitive abilities, or G, or intelligence or IQ
Specific cognitive abilities e.g. verbal, spatial, memory
Learning abilities e.g. reading, maths

Question 2

Why study nature and nurture of cognitive abilities?

Answer 2

Highly reliable and stable
Predict important social outcomes such as educational and occupational and health levels
Increasingly importance in knowledge based society
Focus on STEM (science, technology, engineering and maths) subjects
Lots of individual differences in cognitive learning abilities

Question 3

Do countries differ on PISA maths scale?

Answer 3

Yes
Best = Chinese students
Worst = Mexican students
UK and Russia = centre of the distribution

Question 4

Are individual differences larger than differences between countries?

Answer 4

Yes, 90% overlap of individual differences, they are larger than the differences than exist between countries

Question 5

How much of variance do differences between schools account for?

Answer 5

10%

Question 6

How much of variance is within schools?

Answer 6

90% - individual differences

Question 7

What are cognitive and learning abilities?

Answer 7

Heritable traits

Question 8

What is the behaviour genetic for education?

Answer 8

A book focussing on genetic studies

Question 9

Are both environment and genes important?

Answer 9

Yes, people differ in how they learn

Question 10

How do we look at the role of nature and nurture?

Answer 10

Use genetically informative research designs - twin designs and adoption studies, important to combine the results from both studies because they both have limitations

Question 11

What is included in non shared environment?

Answer 11

Measurement error, this is a limitation of the approach as it could be quite high, sometimes non shared environment may look higher than it is because it includes an error

Question 12

Are literacy and numeracy heritable than g?

Answer 12

They are highly heritable at ages 7 and 9, G isn’t very heritable till age 12

Question 13

Why are literacy and numeracy more heritable than G?

Answer 13

Because they are taught skills so are due to educational equality - the environment is similar in schools for children so most differences are explained by genetic differences, they stay stable as the environment doesn’t really change

So, if a skill is taught, heritability is higher

However, G isn’t taught in school so lots of different factors, as getting older, choose the environment so will change heritability estimates

Question 14

Support for the hypothesis about literacy and numeracy being taught in schools?

Answer 14

Cross national comparisons show that heritability of early reading skill is greater in societies which teach reading regularly and consistently than other societies

Question 15

What does heritability measure?

Answer 15

Population at a specific time

Question 16

What happens to differences between MZ and DZ twins in terms of verbal and spatial abilities?

Answer 16

Differences become larger as they get older

Heritability increases from childhood into old age

Question 17

Does heritability increase throughout the life course?

Answer 17

11,000 pairs of twins from 4 countries
Main findings - heritability of intelligence increases from 40% in childhood to 80% in later adulthood
age 9 - 40%
adolescence - 55%
young adulthood - 66%
Significant decrease in shared environment

Question 18

What is the explanation for heritability increasing over the life course?

Answer 18

1. more genetic factors come interplay with age, more genes become active
2. when they grow up, acting more actively in terms of their environment. choose their environment based on genetic predisposition - gene environment correlation

Question 19

Why is abnormal normal?

Answer 19

Genes associated with disorders are expected to be associated with dimensions
It opens up opportunities for considering positive genetics- how children flourish rather than flounder

Question 20

What is the one gene, one disorder hypothesis?

Answer 20

That one gene/mutation causes mental retardation/intellectual disability
Very small amount of cases

Question 21

What is the quantitative loci hypothesis?

Answer 21

There are multiple regions of DNA which combine together to contribute to development
Genetic factors are risk factors, all add together

Question 22

Polygenic trait model

Answer 22

Cognitive traits are controlled by more than one genetic variant
Each genetic variant is additive to the others
The hallmark of polygenic traits: bell curve distribution and continuous distribution
Bell curve - some people will have many performance lowering alleles (reading disability), some will have some (normal) and some won’t have any at all (high performance)

Question 23

What are common disorders?

Answer 23

The extremes of the same genetic factors responsible for heritability throughout the distribution