3 - Heritability Flashcards
define heritability
extent to which variance of phenotype is due to genotypic variance
what is H2
the estimate of average proportion of variance of any behaviour thought to be accounted for genetic factors across the population
what is genotype
the DNA for construction and maintenance of organisms
what is phenotype
organisms’ outward characteristics influenced by shared and non shared environments plus additive genetic variation
define endophenotype
manifestation of bhvr, intelligence, or personality directly coded for by genetics
is heritability fixed and constant
no, as it can change with the environment
what are three types of environmental effects on personality
biological and maternal effects
family
schooling
what are 5 biological and maternal effects
nutrition lead exposure prenatal factors maternal effects culture
how does nutrition affect personality
vitamin-mineral supplements increase IQ but is controversial
longer breastfeeding means relatively higher IQ and verbal intelligence
how does lead exposure affect personality
higher blood lead conc means lower IQ although may be due to circumstances causing exposure not actual exposure
how do prenatal conditions affect personality
heavily smoking reduces IQ test performance when sons are 18/19
is FAS related to IQ
no
name some effects of FAS
memory problems
poor spatial relationship skills
abstract thinking deficits
what do maternal effects on personality show
prenatal conditions affect genetic variation and concordance rate between twins meaning the environment interacts with biology
in Western culture what is a sign of intelligence and so is promoted
decontextualisation: detaching self from a situation and thinking abstractly
how does family SES affect personality
higher SES significantly increases IQ even when other factors are considered and childhood SES has enduring effects
why is SES as a factor of intelligence disputed
high SES have more resources and ability to provide better education and nutrition
what effect increases with childhood SES
additive genetic effect
effect of family size and birth order on IQ
larger families and being born later lower IQ, both of which interact with each pther
how does education affect intelligence and vice versa
schooling increases intelligence-related abilities
intelligence affects schooling length and attendance
difference between narrow and broad heritability
narrow has only additive genetic variation
broad has additive and non-additive, e.g. dominance and epistasis