Nature and Nurture of Cognitive Development Flashcards
What is cognitive development?
General cognitive abilities, or G, or intelligence or IQ
Specific cognitive abilities e.g. verbal, spatial, memory
Learning abilities e.g. reading, maths
Why study nature and nurture of cognitive abilities?
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
Do countries differ on PISA maths scale?
Yes
Best = Chinese students
Worst = Mexican students
UK and Russia = centre of the distribution
Are individual differences larger than differences between countries?
Yes, 90% overlap of individual differences, they are larger than the differences than exist between countries
How much of variance do differences between schools account for?
10%
How much of variance is within schools?
90% - individual differences
What are cognitive and learning abilities?
Heritable traits
What is the behaviour genetic for education?
A book focussing on genetic studies
Are both environment and genes important?
Yes, people differ in how they learn
How do we look at the role of nature and nurture?
Use genetically informative research designs - twin designs and adoption studies, important to combine the results from both studies because they both have limitations
What is included in non shared environment?
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
Are literacy and numeracy heritable than g?
They are highly heritable at ages 7 and 9, G isn’t very heritable till age 12
Why are literacy and numeracy more heritable than G?
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
Support for the hypothesis about literacy and numeracy being taught in schools?
Cross national comparisons show that heritability of early reading skill is greater in societies which teach reading regularly and consistently than other societies
What does heritability measure?
Population at a specific time
What happens to differences between MZ and DZ twins in terms of verbal and spatial abilities?
Differences become larger as they get older
Heritability increases from childhood into old age
Does heritability increase throughout the life course?
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
What is the explanation for heritability increasing over the life course?
- more genetic factors come interplay with age, more genes become active
- when they grow up, acting more actively in terms of their environment. choose their environment based on genetic predisposition - gene environment correlation
Why is abnormal normal?
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
What is the one gene, one disorder hypothesis?
That one gene/mutation causes mental retardation/intellectual disability
Very small amount of cases
What is the quantitative loci hypothesis?
There are multiple regions of DNA which combine together to contribute to development
Genetic factors are risk factors, all add together
Polygenic trait model
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)
What are common disorders?
The extremes of the same genetic factors responsible for heritability throughout the distribution
