Genetics Flashcards
1
Q
percentage of variance
A
the fact that individuals vary, an this variability can be partitioned into percentages that are due to different causes
2
Q
family studies method
A
- for traits with a large genetic component, the degree of similarity among relatives of that trait will be in proportion to the amount of genetic relatedness/degree of kinship among them
- ie. you’d be more similar to your siblings (50% shared genetics) than your grandparents (25% shared genetics) on a trait with a high genetic component
- limitation: similarity observed may also be due to shared environment (ie. your similarity to siblings may just be due to growing up in the same house w/same parents) -> no equal environments assumption
3
Q
twin studies on mental toughness
A
- mental toughness: important for academics, achievement, goal attainment, etc. -> involves commitment and control
- twin studies suggest genetics account for 54% of variance in mental toughness -> genetic and environmental element
- commitment component demonstrated greatest degree of environmentality -> implications for clinical interventions to increase it
- showed positive correlation with all Big 5 traits except neuroticism (negative correlation)
4
Q
adoption studies
A
- High correlations on traits between adoptive children and adoptive parents provide evidence of environmental influence
- High correlations between adopted children and genetic parents provide evidence of genetic influence
- Major strength: genetic parents are providing no environmental influences -> genetics and environment can no longer be confounded
- Limitation: selective placement (ex. Choosing a child that looks like them; can happen subconsciously) -> confounding of genes/environment
5
Q
behavioural genetics research on neuroticism and extraversion
A
- twin studies show that neuroticism and extraversion are very heritable (~50% genetics)
- adoption studies show slightly less evidence for heritability, and no direct evidence for environmentality (ie. extraverted adoptive parents don’t make their introverted children extroverted)
6
Q
behavioural genetics research on other traits
A
- activity level, emotionality, sociability, persistence, fear, distractibility show moderate heritability
- psychopathic traits show moderate-high heritability
- aggression shows high heritability
7
Q
Results from Minnesota Twin Studies
A
- most traits show modest degree of heritability (including ones we think are highly heritable and highly environmental)
- some attitudes show heritability (ex. conservatism), but some don’t (ex. religiosity)
- occupational preference influenced by heritability
8
Q
sexual orientation
A
- included as part of personality (though controversially) -> stable over time, associated with different life outcomes
- heritability varies (30-70%); is typically less than originally thought, but is partly heritable
- may be due to differences in hypothalamus or a gene on the X chromosome
- strongly related to childhood gender non-conformity (ie. feminine boys highly likely to be gay men)
- twins studies show low concordance (probability that if one twin is gay, the other will also be)
9
Q
what other things are heritable?
A
- drug use, alcoholism
- likelihood of marriage, divorce, marital quality
10
Q
influence of shared environmental influenced vs. unshared environmental influences
A
- Non-shared environments and genetics have much higher influence on personality than shared environments
- Ex. Correlation of personality traits of adopted siblings (who share environments but not genes) is only .05 -> not causing personality similarities
- Shared environments tend to influence attitudes, religious beliefs, political orientations, health behaviours, etc. but NOT personality
11
Q
genotype-environment interaction
A
- different responses of people with different genotypes to the same environment -> Environment has a different impact depending on the person’s genotype
- ex. introverts and extroverts responding differently to noisy environments
- ex. Steve Jobs’ genes predisposed him to high assertiveness and low neuroticism, leading to him recovering after getting fired from Apple and starting a new business rather than withdrawing/failing
12
Q
genotype-environment correlation (and its 3 sub-types)
A
- exposure to environmental conditions depends on person’s genotype (ex. a highly intelligent kid might induce his parents to provide more intellectually stimulating environments for him, unlike a less intelligent kid; Steve Jobs’ creativity led him to create Apple)
- passive gen.corr: seen in early childhood; parents provide genes & environment to kid without any action from kid (ex. buying books for smart kid)
- reactive gen.corr: parents respond to kids differently based on genotype (ex. kid doesn’t like to be hugged, mom is less physically affectionate with him) -> same as evocation
- active gen.corr: people seek out environments based on genotype (ex. smart people reading lots of books) -> same as selection
13
Q
molecular genetics
A
- methods designed to identify specific genes associated with personality traits
- ex. association method -> seeing whether individuals with a particular allele/gene are higher or lower in certain traits
- DRD4 gene is most frequently examined (codes for dopamine receptor, related to novelty-seeking)
14
Q
environmentalist view
A
personality is determined by socialization processes, such as parenting
15
Q
nature/nurture vs. person/situation debate
A
- Nature/person:
- Person: individual differences or personality characteristics
- Nature: genetic makeup
- Nurture/situation:
- Very similar – environmental and contextual factors
- Nurture focuses on childhood environment and parenting
