Chapter 8: The Interplay Between Genes and Environment

Question 1

What is a passive genotype-environment correlation?

Answer 1

When a child’s genotype is correlated with their family environment.

Question 2

What is an evocative genotype-environment correlation?

Answer 2

When individuals are reacted to on the basis of their genetic propensities.

Question 3

What is an Active genotype-environment correlation?

Answer 3

When individuals seek or create environments correlated with their genetic proclivities.

Question 4

What method can be used to find passive correlations?

Answer 4

Comparing the correlation between environments and traits in adoptive vs. non-adoptive families.

Question 5

What is an example of a passive correlation?

Answer 5

HOME and cognitive abilities. There was a greater correlation between HOME scores and cognitive abilities in non-adoptive families.

Question 6

What is a question asked for a multivariate analysis? What kind of correlations can it find?

Answer 6

Is there an association between an environment and a trait explained by the genetic overlap between the two? It can find any type of correlation.

Question 7

When do GxE interactions occur?

Answer 7

When the relationship between the two variables (genes -X1 and y) depends on a third variable (env. -X2) When genotype (X1) and a trait (Y) depend on environment (X2).

Question 8

What is a genotype-environment interaction?

Answer 8

Genetic sensitivity or susceptibility to environments.

Question 9

What is a diathesis-stress interaction?

Answer 9

A type of GxE interaction in which individuals at genetic risk for a disorder (diathesis) are especially sensitive to the effects of risky (stress) environments.

Question 10

What is a children-of-twins study design?

Answer 10

A study that includes parents who are twins and the children of each twin.

Question 11

What is a method for finding evocative and active correlations?

Answer 11

Compare the correlation between birth parent trait and adoptive family environment.

Question 12

What are two issues with the diathesis stress model of interaction?

Answer 12

1. Environment is already linked to genotype. 2. Traits are polygenic.

Question 13

What are two examples of a diathesis stress interaction?

Answer 13

1. 5-HTTLPR and suicide. 2. MAO-A and DAT1 and Parental Negativity.

Question 14

What is an example of a differential susceptibility interaction?

Answer 14

5-HTTLPR and depression. Those with the “risk” gene may do better in non-stressful environments.

Question 15

According to the differential susceptibility model could “sensitivity” allele predict better treatment results in the future?

Answer 15

Yes.

Question 16

What is an example of an evocative correlation found using method 2?

Answer 16

Adoptive parent hostility and children’s peer behavior. Children’s low social motivation evoked more hostile reactions.

Question 17

What is an example of a correlation found using multivariate analysis?

Answer 17

50% of the phenotypic correlation between HOME scores and children’s cognitive ability is mediated genetically.

Question 18

What is an example of a finding from a twin studying assessing GxE interactions?

Answer 18

The heritability of general cognitive ability is significantly greater in families with more highly educated parents than in families with less well-educated parents.