Lecture 6 Flashcards
Traits that are highly heritable
Visual acuity, eye color, sociosexual orientation, verbal intelligence.
Traits that are low in heritability but influenced by genetics
Number of eyes, sexual orientation, presence vs absense of basic language skills.
What is the relation between phenotypic variation and genetic variation?
Quantifies the importance of genes by identifying how much phenotypic similarity on a trait can be predicted by genetic similarity. “How much”
Why is heritability a statistic that can tell us about how important genes are in determining a trait within a population, rather than applying to an individual?
The “which”-approach identifies particular versions of genes which are found more frequently among those with different phenotypes. That means finding genes that are more existing in certain types of people.
What is additive genetics (A) and when do we see them?
Genetic effects on the phenotype which do not depend on the presence of other genes.
The similarities seen between identical twins who were raised in different homes come from additive genetics because they haven’t shared environment.
What is shared environment (C) and when do we see it?
The effects of the environment that make members of a family more similar to each other.
Any similarity among adopted siblings are tribute to shared environment. There are no genetics to “blame”, only the environment.
What is unique environment (E)?
The effects of the environment that make members of a family different from each other.
What do you look at when trying to found out how important A, C and E are?
You look at diverse relationships with different components.
You exhibit similarities or not in different sibling types.
What is the correlation on adopted siblings?
.05
Reared-together MZ twin personality correlation?
Around .5 because 0.5 = A + C
Reared-together DZ twin personality correlation?
Around .25 because 0.5 * A + C = 0.25
What is the gene-environment correlation (rGE)?
When a given gene or set of genes are found more often in people who are in certain environmental contexts.
It makes it harder to identify whether some aspect of the environment causes a trait or is simply correlated with genes contributing to a trait.
What is passive rGE?
When you just passively receive the gene and the environment. It isn’t an active choice to like a certain thing, but your parents do it and therefore, it is in your environment and genes.
What is evocative rGE?
Evoking a response from others that’s causing a match between the gene and the environment.
What is active rGE?
If you have a gene, you control your environment to do the thing that your gene says. The ability to causal influence your environment.
How was rGE shown in the Ge et al. adoption study involving adoptive parent behaviour?
Finding: The personality traits of the biological parent predicted the behaviour of the adoptive parent.
Reason why: Something of the personality from the biological parent is shared with the personality of the adoptive child. Then, this has influenced the adoptive parent!
Do genes become more or less important for psychological characteristics as the individual ages?
Genes account for very little in the little ages but become substantially more important later (tops around 20).
How stable are political views when looking at MZT and DZT?
MZT seems to have more similar politics trough life where DZT seems to become less similar. MZT and DZT have around the same correlation in politic view when 17-19 years old. But when genes become more influence – when aged and moved out – DZT become less similar in political view.
