ID: nature and nurture (6)

what do twin studies suggest about personality?

it is heritable

which trait is most heritable?

openness (0.61)

which trait is the least heritable?

neuroticism and agreeableness (0.41)

what are the average heritability estimates in family/adoption studies?

around 30%, typically lower than twin studies which are around 40%

what is heritability?

the portion of variance within individuals that can be attributed to genetics

what is the candidate genes for extraversion?

DRD4 7R

people with at least 1 7-repeat allele have a higher novelty seeking than other genotypes

what is the nickname for the DRD4 7R

wanderlust gene

what is the candidate gene for neuroticism?

short allele for serotonin transporter gene

this terminates the action of serotonin by facilitating its reuptake from the synapse

what is a Genome-Wide Association Study?

instead of having a candidate gene in mind, you set markers across the whole genome

you should find all variants associated with the phenotype of interest

this is hypothesis free, exploratory, lower power, large number of variants

what does massive polygenicity implicate?

Missing heritability may be due to the existence of multiple genes that all have a small effect

• If scores of genes contribute to a given trait the single variant genes will only predict a very small amount of the variance in that trait

• Essentially, there may be many and multiple genes all predicting very small amounts of the variance

what is the epigenome?

whilst not part of the DNA, impact on DNA and gene activation- influence which genes are turned on and off at different times and places in the body

What is the Belsky, Steinberg and Draper hypothesis?

­Individuals differ in sex and relationship behaviours, like fidelity, age at onset of sexual activity, sociosexuality etc

­What if early and promiscuous sexuality were an adaptive response to certain types of early experience?

What did the washing machine learning method for genome-wide association studies find?

42 SNP sets that identified 727 gene loci and were significantly associated with one or more of the character profiles

­Appeared consistent across cultures and environments, and explained nearly all heritability expected for character in each sample (50-58%)