Nature and nurture Flashcards
(25 cards)
heritability E
0.53
heritability for N
0.41
heritability for C
0.44
heritability for A
0.41
heritability for O
0.61
how are twin/family studies used for personality
estimates in the range of 40% are common compared to MZ twins
typically lower <30% when in adoption studies
what is heritability
the proportion of variation in the
characteristic that is associated with variation in genetic
material.
what is the candidate gene approach
hypothesis driven - constrained by prior knowledge
allows for systematic song
candidate gene approach to extraversion
polymorphic DRD4 gene - includes 2 to 11 repeats
DRD4 7R results in the expressed
dopamine receptor having less affinity for dopamine binding
People with at least one 7-repeat allele have higher Novelty Seeking than other genotypes
candidate gene approach to n
serotonin transporter gene terminates serotonin action by facilitating its reuptake
44bp deletion/insertion
generated two alleles of 5
HTTLPR: Short (14-repeat) and
Long (16-repeat).
short allele appears to be associated with decreased serotonergic funtion
candidate gene related to neuroticism scores
individuals with short copy genes had higher neuroticism scores
concluded that polymorphism accounted for 3-4% of variance
problem with candidate genes in personality research
associations found but issues with non-replication
effects are small - only a few perecnt of variance explained - 1000s of participants required
what is the genome wide associations approach
instead of candidate gene markers across whole genome
should find all variants of phenotype of interest
isue with the GWAS
missing heritability - find some associations but only <1% of variance explained
what may result in missing heritability
multiple genes that all have a small effect - only small amounts of variance
gene-gene interactions
gene-environment interactions
what is the epigenome
a secondary layer of biochemical information that modify or mark the genome in a way that alters the instructions given by the DNA.
what do epigentic factors do
influence which genes are turned on and off in the body at different times and places - can be altered by the environment
what is the Belsy, Steiberg and Draper hypothesis
-individuals differ in sex and relationship behaviours
-early and promiscous sexuality may be an adaptive response to early experiences
-unsupportive care from caregivers in first 5-7 years is a cue of harsh ecological conditions
how is childhood experience and age at first pregnancy related
prospective study of around 3000 women
predictors were four measures of parental investment in first 7 years of life
-breastfed
-long separation from mum
-dad’s role
-residential moves
results of pregnancy and early experiences
earlier first pregnanices correlated with more adversities
other evidence of Beltsy, Steiberg hypothesis
age of menarche and sexual behaviour differ between one and two parent households
how was childhood adversity and infidelity in adulthood investiagated
retrospective study - reflecton early psychosocial stress
correlations between adverse experience and infidelity behaviours
how was GWAS used in human character
Identified “clusters of SNPs” within individuals
Identified clusters of people with “distinct profiles of character
traits”.
Found 42 SNP sets that identified 727 gene loci and were
significantly associated with one or more of the character
profiles.
which genes were related to each process
intentional goal setting - conscientiousness
self-reflection - neuroticism
empathy - agreeableness
episodic learning and memory - openness
