Advanced nature and nurture studies Flashcards
Do genes and environment contribute independently to a specific trait?
They both have an influence by interplaying with each other
Are environments heritable traits?
Yes, many measures of the environment that are important for the child development are under genetic influence (15-40%):
family environment
parental discipline and warmth
peer relationships
controllable life events and exposure to trauma
When events aren’t heritable?
Uncontrollable life events - death of a parent
What do humans do?
Select, modify and create environments in life with their genetic propensities
What does nature via nature mean?
Gene environment correlation - when individuals with a genetic propensity for a trait are in environments, they choose or create environments which support expression of the trait
What does R refer too?
Gene-environment correlation
What are the three sources of gene environment correlation?
Passive
Evocative
Active
all differ in the source of the correlation
What is a passive correlation?
Parental genes influence parental behaviours that play a role in determining the kind of environment that they provide
What is an evocative correlation?
Child genes influence child behaviours that play a role in evoking different types of responses in people
What is an active correlation?
Child genes influence child behaviours that play a role in determining how children shape and select their environments
Do genes influence the environment directly?
No they influence the way that children behave, which creates different responses/environments
What are examples of passive correlation?
Parents of high IQ provide genes and enriched rearing environments
children with genetic vulnerability to anti-social behaviour is due to exposure to family maltreatment
Evidence for the passive correlation
Adoptive families vs non adoptive families - compare parent-child correlations
if similarity between adopted, can only be due to the environment
Results: biological families = r = .50, adoptive families = .20 - when no genetic influences, still a correlation which is due to just environment
What are examples of evocative correlation?
Children with genetic risk for behavioural problems evoke a negative type of parenting or negative reaction from peers
children with positive personality evoke more positive responses from parents/peers
Evidence for the evocative correlation
Adoptive families: genetic risk of child is due to behaviour of biological parents
looked at negative parenting at 5 time points of the Childs life
Adopted children at genetic risk based on biological traits - experienced higher level of negative control
adopted children with no genetic risk - less negative control
Examples of active correlation
Athletic individual seeks out athletic endeavours
anti social person seeks out anti social peers
Evidence for the active correlation
64% of the variance in adolescents exposure to friends who smoke and drink could be explained by genetic influences, no shared environment
genetic factors can influence the formation of friendships with substance using peers
Gene environment correlation across development
The influence of the passive rGE declines from infancy to adolescence
The importance of the active rGE increases over the same period
The degree to which experience is influenced by genetic factors increases with development, as they select they own experiences
What is nature by nurture?
The gene environment interaction
What is the gene environment interaction?
Genetically influenced sensitivity to specific environment. Genetic influences on a trait depend on the environment
Specific environments and genetic propensities to these environments predict a trait
Gene environment interaction
Effects of physical maltreatment on risk for conduct problems for children who were at high risk for these problems
Effect of maltreatment on risk for conduct problems was strongest for those at high genetic risk - 24% increase in a conduct disorder
Children at low genetic risk for a conduct disorder - 2% increase in the probability of getting a conduct disorder
What are the two types of gene environment interplay?
Gene environment correlation - the role of genes in exposure to environment
Gene environment interaction - genetic sensitivity or susceptibility to the environment
How does the environment get under the skin?
Through epigenetics
What is epigenetics?
Determines whether genes become active or not, how much proteins are made and where and when, depending on the environment
our environment doesn’t change our DNA, but changes if genes are active or not
What do genetics determine?
What proteins are synthesized
Maternal lick and offspring behaviour
2 groups, high nurturing and low nurturing
high nurturing raise low anxious offspring and less stressed
low nurturing raise high anxious offspring
The nurturing behaviour of a mother rat during the first week of life shapes her pups epigenomes: in offspring of low nurturing, hypermethylation of glucocorticoid receptor gene leads to lower expression of GR and higher levels of stress and anxiety
pattern stays put, even after pup becomes adults
