Ch. 9: Personality Inheritance Flashcards
(32 cards)
How to study behavioral genetics with twins
- compare self-reports/observations
- correlation coefficient: compare MZ vs DZ pairs
- genetic influence
Heritability coefficient
degree that variance of trait in populations can be attributed to genetic variance (difference btw correlation among MZ & DZ twins)
What’s the avg heritability of traits (twin studies)?
40% of behavioral variance accounted by genetic variance
Heritability % of the Big Five
42 to 57%
What does it mean that a trait is 50% heritable?
50% of degree to which trait varies across population can be attributed to genetic variation
What only trait is not influenced by shared env?
extraversion
Limitations of heritability calculations (2)
- Not nature-nurture ratio
- Doesn’t tell you how genes affect personality
Gene DRD4: NT?
affects dopa rec development (beh/emotional ctrl)
Short allele 5-HTT: trait, brain activity?
> neuroticism (anx)
> amyg activity to fearful/unpleasant stim
COMT gene: NT, trait, intelligence?
- assoc w higher dopa levels in PFC
- extraversion
- reasoning
How is IQ heritable?
as the intellectual env improves, heritability of IQ seems to increase (mostly based on env in impoverished env)
Niche picking
ppl tend to select/create env compatible with/that magnify their genetically-influenced tendencies
(active person-env transaction)
What did Caspi & Moffitt discover about 5-HTT?
-ppl w short allele 5-HTT: more likely to dev depression after stressful experiences
-no outcome difference btw long VS short allele if no stress
(not replicated)
Describe the Model of Sources of Neuroticism
- general bio & psyc vulnerabilities;
- create inability to handle stress;
- neuroticism;
- trait can interact w neg experiences;
- mental illness
Genome-wide association study: process
- thousands of genes + personality data
- computer searches for associations consistently found in different samples
Evolutionary approach of behavior
if a behavioral tendency helped ppl survive & reproduce, it’ll likely appear in subsequent generations
What Big 5 traits are involved in having more children?
high extraversion, low conscientiousness
Describe the evolutionary mismatch
modern env is mismatch with human history (natural env, support from community, resources)
Evolutionary roots of aggression (necessary/harmful role)
-aggression: protect one’s env // murder, war
Define inclusive fitness (altruism)
tendency to protect others (esp relatives) helps survival of one’s own genes in future generations
Sociometer theory & evolutionary self-esteem
- self-esteem evolved to monitor how accepted you are by others
- ppl who did not try to be accepted failed to survive & reproduce
How could depression promote survival?
- emotional pain signals that chances of reproducing/survival are at risk
- cry to seek social support, fatigue/pessimism prevents wasting energy/resources
Describe Life History adaptation (fast vs slow)
- Fast: species that reproduce young and often who don’t protect offspring = live in dangerous circumstances & die young (reproductive success)
- Slow: long-lived species reproduce later & nurture offspring
Fast vs slow life history in modern times & which is better?
- safe, predictable env = slow (few children, use resources to raise them)
- dangerous/unpredictable = young parents, less likely to stay and raise them (male)
neither is better – each has trade-offs, each adapted to diff env
