PSYC10004 Lecture Notes - Lecture 4: Twin, Selective Breeding, Heritability
28 Jun 2018
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LECTURE 4 – DEVELOPMENT: CONTRIBUTION OF GENES & ENVIRONMENT
“Is it because of our environment and our upbringing or, genetic factors beyond our control, or, is it a
combination of both.”
HOW MUCH?
Concerned with variability across a population (diff. in
people)
Expressed as HERITABILITY proportion of observed
variance in a population
oCauses problems change in environment, alters
heritability estimates
HERITABILITY: what’s due to genetic & environment
Amount of variability in population attributable to hereditary influence (genetic contribution)
Behavioural geneticists use two major strategies to assess hereditary contributions to behaviour:
oSelective breeding – happens in many animals/plants, can’t use on humans
oFamily studies – much harder to control
Estimates amount of genetic variation between individuals in a population beyond that accounted
for by genetic determination
E.g. number of fingers on one hand most people will have 5 digits
oThose who don’t have 5 digits – what proportion are those genetically determined or
environmentally influenced
oGenetic determination = high
oHeritability of no. of fingers = very low (I.E. mainly due to accident)
Genetics have a role in differences in height between people not the same as asking how much
genetic influences just one person
NATURE AND NURTURE – physical structure, intellectual capacity, personality characteristics
interaction/interplay between genetic material & environmental experiences
Mendel – observed patterns of inheritance in pea plants
Watson/Crick – structure of DNA – basic component of hereditary transmission
Three key elements:
oGenotype – genetic material an
individual inherits
oPhenotype – observable expression of
genotype
find more resources at oneclass.com
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Document Summary
Lecture 4 development: contribution of genes & environment. Is it because of our environment and our upbringing or, genetic factors beyond our control, or, is it a combination of both. Concerned with variability across a population (diff. in people) Expressed as heritability proportion of observed variance in a population: causes problems change in environment, alters heritability estimates. Amount of variability in population attributable to hereditary influence (genetic contribution) Behavioural geneticists use two major strategies to assess hereditary contributions to behaviour: selective breeding happens in many animals/plants, can"t use on humans, family studies much harder to control. Estimates amount of genetic variation between individuals in a population beyond that accounted for by genetic determination. Genetics have a role in differences in height between people not the same as asking how much genetic influences just one person. Nature and nurture physical structure, intellectual capacity, personality characteristics interaction/interplay between genetic material & environmental experiences. Mendel observed patterns of inheritance in pea plants.
