Nature-Nurture: family and genetic influences

Question 1

Across how old is there genetic contribution to LADs?

Answer 1

2-16 and presumably into
adulthood

Question 2

True or False?

Genetic influences are not static: heritability of LADs increases during the development

Answer 2

True

Question 3

True or False?

FOXP2 gene has been discovered (KE family) and is the only gene causing language development

Answer 3

False - many other genes play the role in language development

Question 4

Name the three types of interplay

Answer 4

Epigenetics = E -> G (environment influence genome)

Gene-Environment Correlation = G -> E (gene modifies environment)

Gene-Environment Interaction = G x E (genetic + environmental to put people at risk to developmental-specific traits)

They do not act independently from each other

Question 5

Describe what is genetics

Answer 5

Genetic material (DNA) is passed on from parents to offspring (vertical genetic transfer)

Human genome = It’s a molecule of DNA. 3 billion nucleotide base pairs.

There are 20-25,000 genes in the human genome

More than 99% of the DNA sequence = same ~ 1% of the DNA sequence is variable (the source of individual differences)

Question 6

What is gene expression?

Answer 6

When DNA sequence of a gene is converted
into functional protein structures.

Gene expression changes to produce different proteins.

How much + duration of proteins are made = can vary

Question 7

What is the difference between genetics and epigenetics?

Answer 7

Genetics (i.e., DNA sequence) = what specific proteins are synthesised.

Epigenetics = how much of the proteins is made, and where + when it is synthesised

Question 8

What is DNA methylation?

Answer 8

Methyl groups attach to DNA compacting it + preventing its code from being read/ made into proteins

This is a well studied example of epigenetics.

Question 9

What is epigenetic modulation?

Answer 9

Kanherkar et al. (2014) = identified many environmental effects on genetics
Psychological state
Social interaction
Diet
Disease exposure
Exercise
Financial Status
Drug abuse
Alternative meds
therapeutic drugs
Seasonal correlations
Toxic/ chemicals
Microbiome

Question 10

What happened in Weaver et al. (2004) study?

Answer 10

High-nurturing mothers = low anxious offspring vs Low-nurturing mothers raise = high anxious offspring Nurturing bhvr of a mother rat = pups’ epigenomes.

In low-nurturing offspring = glucocorticoid receptor gene (Nr3c1) = off + leads to higher level of stress and anxiety.

Epigenetic pattern that mum causes = lasts even after the pups become adults.

Question 11

Describe the gene-environment correlation.

Answer 11

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

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

Question 12

What are the three types of GE correlation?

Answer 12

Passive
Evocative
Active:

Question 13

What is Passive GE correlation?

Answer 13

Parental genes influence parental behaviours = a role in determining the kind of parenting style they give.

Source = parents and siblings.

Example:
Children with genetic vulnerability to antisocial behaviour is exposed to family maltreatment

Question 14

What is Evocative GE correlation?

Answer 14

Child genes influence child behaviours = a role in eliciting different types of responses in other people

Source = anybody

Example:
Children with positive personality (high extraversion) evoke more
positive responses from parents/peers

O’connor et al. (1998) = studied adoptive families, children were measured @ 7,9,10,11 and 12. They identified non-risk + at risk for anti-social bhvr in children and measured against mean level of neg. control. Children at risk = had higher level of neg. despite the environment. Their bhvr elicited neg. response from their carers.

Question 15

What is Active GE correlation?

Answer 15

Child genes influence child behaviours= a role in determining how children shape + select their environments. A “rich get richer’ effect.

Examples:
Athletic individual seeks out athletic endeavours
Antisocial person seeks out antisocial peers

Question 16

Describe GE across development

Answer 16

important for changes in development

Influence of passive GE = declines from infancy to adolescence, but importance of the active GE increases throughout period

Identified = the extent of how an experience is influenced by individual’s genetic factors increases with development
2 possible mechanisms:
New genes = important (genetic innovation)
individuals select their own experiences (genetic amplification)

Question 17

Describe gene-environment interaction

Answer 17

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

Example:
Jaffee et al. (2005) = A twin study. Twin 1 = genetic marker, Twin 2 = included in study. Child conduct problems as a function of genetic risk and physical maltreatment. Children with the highest genetic risk, were the most abused.

Pleuss and Belsky (2011) = proposed two models = Diathesis-stress and differential susceptibility model. Suggested both environment + genetic factors were important

Diathesis-stress = high risk for neg. environment. Resilient indvdls = genetically won’t experience neg. outcome.

Question 18

What is a limitation of studies looking at the gene-environment interaction?

Answer 18

Studies focus on neg. environments + development of neg. traits e.g conduct problems

We don’t understand the outcomes of pos. environments