Chapter 6 Flashcards
What are the goals of behavioural genetics?
to find out what percentage of the variance of an individual difference is due to genetic influences and what percentage is due to environmental differences
What is heritability?
the proportion of observed variance in a group of individuals that can be accounted for by genetic variance
What are some common misconceptions about heritability?
- heritability does not apply to individuals, only samples/ pops.
- heritability is not constant
- heritability is not a precise statistic - it is an estimate
What do family studies accomplish in personality testing?
correlate the degree of genetic relatedness among family members with the degree of the personality similarity - to see if it is heritable or not
What can Twin studies help us find?
heritability - if identical twins are more similar than fraternal twins, we can say it is heritable.
What do adoption studies show is?
If an adopted child (that has no common genes) shows similarities to the adoptive parents, there is strong evidence of environmental influences on the trait; can also compare to genetic parents and see if genetics or environment play more of a role
What are some examples of shared environmental influences?
number of books at home, quality/quantity of food, presence of technology
What are some examples of non-shared environmental influences?
special treatment from parents, friends, different bedrooms, different experiences
What is genotype -environment interaction?
the differential response of individuals with different genotypes to the same environments (eg. N &E react differently to studying in room with loud noise)
What is the genotype-environment correlation?
the differential exposure of individuals with different genotypes different environments (eg. kid has genotype for high verbal ability, therefore parents provide high stimulation)
What is reactive correlation?
the parent responds to the child differently depending on the child’s genotypes
What is passive correlation?
parents provide both gene & environment but kids do nothing to obtain the environment
What is active correlation?
a person with a particular genotype seeks out a particular environment (sensation seeking looks for risky environments)
