Behavioural genetics Flashcards
(21 cards)
what is behavioural genetics?
Behavioural genetics is the interdisciplinary scientific effort to establish causal links between genes, behavioural traits and neural mechanisms.
what is heritability?
Proportion of phenotypic variance that can be accounted by genetic differences among individuals.
what is polygenic inheritance?
large number of genes contributing to small cumulative (often interracting) effects that then have a normal distribution.
what is a shared environment ? (how genes and environment overtime can interact to produce behaviour. )
Shared environment- the non-genetic factors experienced by all siblings or both twins( a shared environment would be something that influences your decisions despite your genes, so if everyone in your family leaves education at a certain age your likely to do the same.)
whats an Non-shared environment? ( genes and environment overtime can interact to produce behaviour. )
The non-genetics factors which do not correlate between siblings and twins. accounts for all differences between identical twins brought up in the same family household. (Their taste in music, prenatally your different, childhood disease, change in family structure when one sibling was born making their upbringing different.)
How has Francis Galton affected behavioural genetics?
- Identified the normal distribution across a population for intelligence.
- Developed the statistical concepts of regression and correlation. -Designed early twin studies but championed eugenics
How has discovery of DNA affected behavioural genetics?
Genetic testing for single gene disorders identifying those affected - for intervention and prognosis.
What is considered to be environment?
Prenatal, nutrition, illness and social factors.
Define gene-environment correlation.
Life experiences correlated with genetic propensity.
Define gene-environment interaction.
Effects of environment can depend on genetics and the effects of genetics can depend on environment.
define Gene-environment correlation
life experiences are correlated with genetic propensity.
What are the quantitative genetics research methods?
Adoption studies - comparing those reared together and apart.
Twin studies - comparing identical and fraternal, in long-term cohorts.
Combo - twins adopted apart.
What are the molecular genetics research methods?
Candidate gene studies
Genome wide association studies - using SNPs and copy number variants in large numbers
Multivariate genetic analysis - to examine genetic mediation of behavioural associations within individual twin pairs.
what is quantitative genetics?
the use of natural experiments that have occurred such as adoption. twin studies- comparing identical and fraternal in long term cohorts.
what is molecular genetics?
molecular genetics focuses on candidate genetics.
what is molecular genetics?
molecular genetics focuses on candidate genetics.
describe adoption studies
Direct comparison of behavioural phenotype in genetic relatives can evidence the genetic contribution and comparison in environmental relatives.
What are the limits of adoption studies?
- Gradual decline in adoption in high-income countries.
- Adoptive parents and adoptees may be substantially different from normal population.
- Prenatal environment may make contribution before adoption.
- Open adoptions.
Describe twin studies.
Comparison of behavioural trait concordance in monozygotic twins vs. dizygotic twins. Assumed equal environment.
What are the limits of twin studies?
- May not be generalisable.
- expesive to follow up and lost data can effect results.
- Measurement errors.
Describe genome wide association studies.
Large scale molecular genetic studies of unrelated individuals, including comparison of cases vs. controls.
