Nature vs Nurture Flashcards
Behavioural Genetics
The study of genetic influence on personality and behaviour
Selective breeding studies
Desired characteristics are passed on by getting animals carrying the genes to mate
Different strains of genetics are passed on so we can study them
Placed in different environments to study
Family Studies
Look at correlation between genetic relatedness and personality similarity
Problem: environment is shared, we can’t be sure the cause is genetic
Twin Studies
Monozygotic - 100%
Dizygotic - 50%
Monozygotic should be more similar - genetic argument
Heritability Estimate
h2 = 2 (rmz — rdz)
Equal Environment Assumption
the idea that both sets of twins experience the same environment
Adoption Studies
- Able to study the effect of genetics and environment separately
- Biological and adopted parents
Twins - separated monozygotic twins should be more similar than separated dizygotic twins
Limitations of Adoption Studies
Selective placement - children may be adopted into families that are similar to their biological ones
Representativeness - differences in socioeconomic status
Heritability
Describes what parts of personality can be explained by genes
Phenotypic variance
observable individual differences e.g. weight, height etc.
Genotypic variance
individual differences in the total collection of genes possessed by the population
Unobservable
How heritable is personality?
- Personality traits are around 40% inheritable
- Criticism: overestimate, some say it’s 20%
- Not constant, the estimate changes constantly
Temperaments
Personality traits noticeable from infancy, meaning they are likely inherited
- Said to be linked to emotion and arousal
Buss & Plomin’s Temperaments
- Activity level
- Overall level of energy expended
- Related to extraversion
- Two highly correlated aspects: vigor (intensity) and tempo (speed)
- Overall level of energy expended
- Sociability
- How much we want to be with others
- Related to extraversion and agreeableness
- How much we want to be with others
- Emotionality
- How easily and to what extent we are emotionally aroused by an upsetting situation
- Related to neuroticism
- How easily and to what extent we are emotionally aroused by an upsetting situation
Possible additional temperaments
- Impulsivity
- Conscientiousness (or lack thereof)
- Intelligence
- Openness
- Disagreement over whether or not they count as temperaments
Temperaments vs Personality
- Temperaments are inherited
- Personality traits are influenced by genes and environment
Interactions & Correlations
Genetics and environmental factors do not operate separately but interact to influence behaviour
Genotype-Environment Interactions
GxE Interactions
The idea that genes cause us to respond differently to the same situation
Genotype-Environment Correlations
The idea that we are exposed to different environments and situations as a result of our different genotypes
Passive genotype-environment correlation
- Genes and environment combine
- Genes and environment are provided to the child by parents, child remains passive e.g. parents have high verbal ability & read a lot to the child
- Bidirectional causality - unclear
Reactive/evocative genotype-environment correlation
- Environment changes as a result of genotype
- e.g. gifted child is put into advanced classes which further their abilities
Active genotype-environment correlation
- We seek specific environments as a result of our genes which then strengthen those tendencies
- Personality example - extraversion (seeking out group activities and becoming more extraverted) and introversion (spending more time alone and enjoying it)
Positive correlation
environment motivates the expression of a characteristic
Negative correlation
environment prevents the expression of a characteristic
