Gene-Environment Interplay

Gene-Environment Interplay

• genes and environment rarely separable

• we use behavior and molecular genetics methods to study hot they work together

• results can be classifies as falling into 3 patterns

  • Gene environment correlations

  • gene environment interactions

  • epigenetic effects

Gene-environment correlations

genotype is correlated with environments that maximize the expression of genetically influences traits

• both genes and environment are there for the individual to experience the mental health condition

risky/protective genes “hang with” risky/protective environments

• traits that attribute to ADHD and an environment that attributes to ADHD

3 ways that genes might come to be correlated with environments: passive, active, evocative

Gene-environment correlations - Passive

parents pass on genes “for” a trait and parents produce environment which amplify expression of those genes (before children can pick their own environment)

• ex: musical tallen, anxiety

Gene-environment correlations - Active

People with a specific genotype seek out environments which maximize expression of that genotype (choosing our own environment)

• ex: bookworm, agression

Gene-environment correlations - Evocative

genetically influences behaviors/traits evoke a response which amplifies the expression of that behavior/trait

• ex: sociability/extroversion, depressive symptomatology

Gene-environment correlations - reciprocal

mutually influenced - i change you and you change me

Gene-environment correlations - transactional

the effect of reciprocity over time - Dr. B is different to our class than she is to another class

Gene-environment correlations - developmental cascade

the cumulative consequences of transactional processes - if I am more vulnerable than I am probably going to recieve more negative feedback from the environment which amplifies the feeling of vulnerability

• snowball effect

• event —> outcome —> future event —> future outcome

• genes supporting resilience —> resilient functioning —> positive environmental response —> continued amplifies resilient functioning

Gene-environment Intereaction

some genes are only important in certain environments

• genetic vulnerability interacts with particular environments/experiences to confer risk

Epigenesis

Gene expression modulated by environmental experience (“turned on”, “silenced”, “activated”)

• this generally occurs through methylation (silences a gene) and acetylation (turned on/amplifies a gene)

• the earlier the more sensitive