Tuesday, January 27, 2015
The Biological Domain
Genes and Personality - Issues and Controversy
why might the study of genes and personality be controversial?
-> ideology (people may push certain political agendas, by pushing a certain kind of
gene, serious gratiﬁcations such as the legal system) -
> eugenics (discouraging others with certain traits that we want and do not want in
-> others: religious beliefs, science behind these.
Percent of Variance: differences between people due to a certain cause (percentages)
ex: what percent of neurotics is determined by genes or the environment? what is the
percentage of variance between genes and the environment? *
Heritability vs. Environmentally
-amount of phenotypic (measure, observe) variance in a group due to genotypic
(opennes, individual differences in person’s genes)
Environmentality: amount of observed variance due to environment
*it is hard to untangle because there is an interaction between both not one or the
Behavioural Genetics Methodologies
1. Family Studies
-examine correlations between: genetic relatedness of family members and
personality similarities (parents and you 50%) relative should be less similar because
less shared genes.
-parents and children (50%)
-grandparents and grandchildren (25%)
*closer relatives should have more personality similarity
-shared environmental experience (worse limit) temper any ﬁndings we get and put
them in context.
2. Twin Studies
-Monozygotic twins (identical 100%, 1 egg splits)