nature and nurture of language development

Question 1

language development

Answer 1

process of acquiring language

Question 2

language ability

Answer 2

trait that can be assessed through specific tests - in labs, obsv etc

Question 3

what is language development important for

Answer 3

• readiness for school
• qualifications gained
• earnings, literacy skills and mental health in adulthood

Question 4

language capabilities of children in a population follow..

Answer 4

.. normal distribution

Question 5

4 evidence types for genetic factors

Answer 5

• twin studies
• KE family member with language disability - case study
• comparative genomic studies
• genetic association studies

Question 6

Twin studies

Answer 6

• can be used to estimate the effect of genetic factors on a trait
• if genetic factors - similarity should be higher in MZ than in DZ
• can estimate predictability

Question 7

MZ DZ heritability formulae

Answer 7

2(rMZ - rDz)

Question 8

what % of individual differences in language can be explained by genetic factors

Answer 8

40%

so 60% environmental

Question 9

limitations of twin studies

Answer 9

• larges sample sizes needed
• population-based samples are preferred to avoid over-representation of MZ
• difficult to identify twins
• hard to compare ‘level of language’
• twinning effect

Question 10

twinning effect

Answer 10

twins are more likely to have delayed speech and language than singletons

Question 11

KE family members

Answer 11

• half of family had developmental verbal dyspraxia
• less grey matter in some areas of brain
• reduced activity in Broca’s area - responsible for speech production
• deficit in basal ganglia - controls vocal tract

Question 12

KE gene

Answer 12

• mutation in FOXP2 gene
• lost function
• monogenetic trait > caused by a mutation in a single gene

Question 13

Comparative genomic studies: FOXP2

Answer 13

• comparing FOXP2 across humans, primates and other mammals
• FOXP2 is among the most highly conserved 5% of proteins - must have a fundamental role in mammals

Question 14

genetic association studies

Answer 14

• group of cases genes compared to controls
• look at genetic coding of cases
• genetic variant should be more common in individuals in the cases group to assume its responsible for deficit

Question 15

polygenic trait

Answer 15

multiple genes lead to the development of the trait

Question 16

what is language development influenced by

Answer 16

multiple genetic factors in combination with environmental factors