nature and nurture interplay

Question 1

nature and nurture of language development

Answer 1

1. Both genetic and environmental influences are important for language development
   
   2. Genetic influences are not static: heritability of language ability increases during development
   3. Multiple genetic factors have been identified (e.g., FOXP2), suggesting that language ability is a multifactorial trait
2. Genetic and environmental factors do not act in isolation, but co-act, to influence child language development

Question 2

nature and nurture

Answer 2

• do genes and environment contirbute independently to a specific trait?

Question 3

gene environment interplay

Answer 3

• epigenectis = E -> G
• gene environment correlation = G -> E
• gene environment interaction = G x E

Question 4

genetics

Answer 4

• Genetic material (DNA) is passed on from parents to offspring (vertical genetic transfer)
  
  • Human genome is built with 3 billion nucleotide base pairs (3,000,000,000)
  • There are 20-25,000 genes in the human genome
• More than 99% of the DNA sequence is the same for everybody; ~ 1% of the DNA sequence is variable (the source of individual differences)

Question 5

gene expression

Answer 5

• process by which the DNA sequence of a gene is converted into functional protein structures

Question 6

epigenetics

Answer 6

• Genetics (i.e., DNA sequence) determines what specific proteins are synthesized.
  
  • Epigenetics determines how much of the proteins is made, and where and when it is synthesized
  • DNA Methylation - methyl groups attach to DNA compacting it and preventing its code from being read or made into proteins

Question 7

maternal licking and offspring behaviour

Answer 7

• High-nurturing mothers raise low anxious offspring (b) and low-nurturing mothers raise high anxious offspring (a).
  
  • The nurturing behaviour of a mother rat shapes her pups’ epigenomes: in offspring of low-nurturing mother (a), glucocorticoid receptor gene (Nr3c1) is switched off and leads to higher level of stress and anxiety.
  • The epigenetic pattern that mom establishes tends to stay put, even after the pups become adults.

Question 8

nature via nurture

Answer 8

• The environment is not independent of the person: humans select, modify and create environments in line with their genetic propensities.

Question 9

nature via nurture - gene environment correlation (rGE)

Answer 9

• When individuals with a genetic propensity for a trait are in environments, choose or create the environments, that support expression of the trait

Question 10

three types of GE correlation

Answer 10

• Passive:
  
  • Parental genes influence parental behaviours that play a role in determining the kind of rearing environment that they provide
  • Evocative:
  • Child genes influence child behaviours that play a role in evoking different types of responses in other people
  • Active:
  • Child genes influence child behaviours that play a role in determining how children shape and select their environments

Question 11

three types of gene-environment correlation

Answer 11

• passive = parents and siblings
• evocative = anybody
• active = anybody or anything

Question 12

passive GE correlation

Answer 12

· Parental genes influence parental behaviours that play a role in determining the kind of rearing environment that they provide to their children
· Examples:
- Parents of high IQ provide genes and enriched rearing environments
- Children with genetic vulnerability to antisocial behaviour is exposed to family maltreatment

Question 13

evocative rGE

Answer 13

· Genes influence people’s behaviours that play a role in evoking different types of responses in other people
· Examples:
- Children with genetic risk for behavioural problems evoke a negative type of parenting or negative reaction from peers
- Children with positive personality (high extraversion) evoke more positive responses from parents/peers

Question 14

active rGE

Answer 14

· Genes influence people’s behaviours that play a role in determining how people shape and select their environments
· “rich get richer” effect
· Examples:
- Athletic individual seeks out athletic endeavours
- Antisocial person seeks out antisocial peers

Question 15

rGE across development

Answer 15

· The relative importance of the three kinds of rGE effects changes with development:
· The influence of the passive rGE declines from infancy to adolescence, whereas the importance of the active rGE increases over the same period
· The degree to which experience is influenced by individual’s genetic factors increases with development
· Two possible mechanisms:
- new genes become important (genetic innovation)
- individuals select their own experiences (genetic amplification)

Question 16

nature by nurture - gene-environment interaction (GxE)

Answer 16

· Genetically influenced sensitivity to specific environment
· In this case, genetic influences on a trait depend on the environment
· Specific environments and genetic susceptibilities to these environments predict a trait

Question 17

summary

Answer 17

· Nature (genes) and Nurture (environment) do to act in isolation, they correlate and interact – Gene-Environment Interplay
· Epigenetics is an important mechanism of how the environment can control our genome/gets under the skin
· Genetic factors can influence the environment – Gene-Environment Correlation (passive, evocative and active)
· The effects of the environment can depend on genetic factors– Gene-Environment Interaction