8. Nature and Nurture of Language Development

Question 1

Language ability appears in the first ____ years of life, across different ____ and ____

Answer 1

Three
Languages, cultures

Question 2

We have an ____ ability for language ability

Answer 2

innate

Question 3

We can gain language ability without the need of ____ instructions

Answer 3

Explicit

Question 4

Early language skills are very important to children’s ____

Answer 4

Chances

Question 5

The most widely used test by all speech pathologists is the C____ E____ of L____ F____:
Child’s understanding and ____ of language and compares this to their ____ of the same ____

Answer 5

Clinical Evaluation of Language Fundamentals
use, peers, age

Question 6

Nature = ____ factors
Nurture = ____ factors

Answer 6

Genetic
Environmental

Question 7

What are three forms of evidence for the role of nature and nurture?

Answer 7

1. Twin studies
2. KE family with members with language disability
3. Genetic association studies

Question 8

We can compare resemblance of MZ and DZ twins on a specific ____ by looking at ____

Answer 8

Trait
Correlations

Question 9

In twin studies, what do the following stand for??
1. A
2. C
3. E

Answer 9

1. Heritability (proportion of variance in a population attributable to genetic differences between people)
2. Common environment (degree to which siblings in a family are similar to one another, once their genetic similarity has been accounted for)
3. Unique environment (degree to which siblings in a family are different from one another, once their genetic differences have been accounted for)

Question 10

In twin studies of language ability, at age 2 heritability for vocab is ____%, ____% for grammar in boys and ____% for grammar in girls

Answer 10

26, 52, 43

Question 11

What are five limitations of twin studies of language ability?

Answer 11

1. Large sample sizes required
2. Population-based samples preferred, to avoid overrepresentation of MZ pairs
3. Difficult to identify twins
4. Language phenotypes are limited and lacking in metrics interpretable for comparisons to singleton age peers
5. Possible twinning effect (twins more likely to have delayed speech and language skills than singletons)

Question 12

Behavioural phenotype: for every test of ____ and ____ that was administered, the group of affected family members was significantly…

Answer 12

speech, language
impaired relative to the unaffected group

Question 13

Neural phenotype: Bilateral voxel-based morphometry analyses showing some of the regions in which affected KE family members have…

Answer 13

significantly reduced grey matter

Question 14

FOXP2 gene is the gene that is responsible for…

Answer 14

the speech and language disorder in the KE family

Question 15

A single mutation in the KE family leads to a loss of ____ of one copy of the FOXP2 gene, and the one copy that remains is ____ for normal brain ____, leading to the speech and language disorder

Answer 15

function, insufficient, development

Question 16

Define monogenetic trait

Answer 16

Cause by a mutation in a single gene

Question 17

A comparison of the FOXP2 gene of humans, other primates and other placental mammals shows that FOXP2 is among the most highly conserved 5% of ____, indicating it has a ____ role in mammals

Answer 17

proteins, fundamental

Question 18

Genetic influences are not ____ - heritability language ability ____ during development

Answer 18

static
increases

Question 19

Multiple genetic factors of language development have been identified, suggesting language ability is a ____ trait

Answer 19

Multifactorial trait

Question 20

Genetic and environmental factors do not act in ____, but ____ to influence child language development

Answer 20

Isolation, co-act

Question 21

How do you calculate heritability?

Answer 21

Heritability = 2(rMZ - rDZ)