Week 2 - Nature & Nurture Flashcards
Mendel’s 1st law
law of segregations
alleles are carried seperately
Mendel’s 2nd law
independent assortment
traits are inherited independent from each other
X-linked disorder
prevalence in males much higher
but not exclusive
polygenetic traits
thousand of genes
a complex trait
normally distributed
doesn’t follow Mendel’s laws
first adoption study
adopted children of biological mothers with schizophrenia
10% affected as well
none of the children of normal mothers
limitations of adoption studies
less adoption nowadays
non-representative samples and selective placement
prenatal environmental influence
open adoption
difference in MZ twins
.8% due to mutations and recombination
increase of twinning
mostly higher age of mothers
some influence by artificial fertilisation, but less so by now
amardillo
always gets identical quadruplet
rMZ
= MZ concordance
= A + C
rDZ
= DZ concordance
= 1/2 A + C
E
= unique environment
= 1 - rMZ
C
= common / shared environment
= (2 * rDZ) - rMZ
A
= additive genetic influence
= heritability
= (rMZ - rDZ) * 2
adoption design formula
(1/2 A + C) vs C
A in adoption designs
??
influence of C
almost only childhood
types of parenting styles
warmth
control (high C in fathers)
negativity (high A in mothers)
passive rGE
passive gene environment correlation
mainly parents
double advantage model
good genes
good home
double disadvantage model
bad genes
bad home
children of twin design
when each twin raises a family
their children share 25% of their genes
evocative rGE
= reactive gene environment correlation
children evoke parenting style etc.
active rGE
creation of own environment according to one’s genotype
neuroticism in relationships
low negative r
GxE
= gene environment interaction
susceptibility to environmental influences depends on genotype
example for GxE in depression
5-HTT gene x negative life events
vantage sensitivity model
sensitive to good stuff
diathesis-stress model
sensitivity to bad stuff
differential susceptibility model
different sensitivity to good and bad stuff
chorion
the placenta
mono- vs dichorionic
amniotic sac
water sac that surrounds embryo
mono- vs diamniotic
how are MZs born
65% monochorionic and diamniotic
differences twins and other siblings
lower weight up to middle school
slower language development
