1. behavioral genetics
2. evolutionary psychology

Franternal twins ("two-egg")

fertilized by two different sperm; dorn at the same time, but they are no diiferent from siblings born at different times, genetically

A statistic called the HERITABILITY COEFFICIENT

heritability quotient= (r mz -r dz) X 2

is computed to reflect this influence between the twins/gene/traits

IQ under 50, where average is 100 it is not heritable

the cause is probably related to the enviroment, because if you have a moderate retarded person their IQ is 50-69-85 ( it is heritable) IQ scores are heritable. but severe mental retardation is not hertible ;/

heritbablity is the proportion of variation due to genetic influence, if there is no variation, then the heritablity will approach zero.

(the less a trait varies across individuals the lower heritability is likley to be) likeise if a trait has low heritablity-->trait may vary less across individuals or it may be the trait that dpends less on ones genes.

DRD4 gene is associated with this

making sens eb/c of the assocation btwn dopamine and brain regulation of cognition and behavior- related to the trait of impulsivity

1. 5-HTT gene associated with serotonin transporter protein, has two variants, _____.
2. chromosomal structure is long and short
3. short structure: score high in neroticism; amygdala responds in higher activity to fearful, unpleaseant stimuli
4. regulates the degree to which the amygdala and the prefrontal cortex work toegther (imp. to brain structure of depression)

associated with higher levels of dopamine in the prefrontal cortex and also with extraversion and reasoing ability

this is so cool because it connects gene/neurotrasmitter/trait/and imp.aspect of intelligence

influences functioning of a range of neurotrasmitters including norepinphrine, serotonin and dopamine

study showed that boys with low MAOA activity showed 85% exhibited "some form of anti-socil behavior" only if the boy had suffered from maltreatment.

1. has begun to document how experience, early on in life, can determine how or even whether the gene is expressed during development
2. genes can change the enviroment and the enviroment can change the genes.

asumes that human behavioral patterns developed because they were helpful or necessary for survival in an evolutionary history of species.

in relation to personality, is to identify a common behavior pattern and then ask how it might have been adaptive (benificial to survival and reproduction) for the human species across the millennia.

this can help people protect his territory, property, and mates, and also lead to domincance in a social group and higher status.

flip side: it can produce murder, fighting, war

you help someone then they will help you, growing crops, i grow a crops of food yours fails, i help you this winter and you help me next winter when my crop potentially fails.

to aid and protect other people, espicially close relatives, because you wnat your genes to survive, so your genes make it to the next generation (called inclusive fitness), even through your relatives, even if you dont produce off spring.

1. developed by psychologist Mark Leary, our feelings of self-esteem evovled to monitor the degree to which we are acccepted by others.
2. signs that we are not adequatley valued and accepted cause out self-esteem to go down, motivating us to do things that will cause others to think better of us so that we can think better of ourselves.

1. evovled as a useful adpation
2. different kinds of depressions have different causes.

1. depression of social loss: a break up with a bf or gf or bereavement is characterized by pain, crying and social support

2. depression that follows failfure: failing an exam or getting fired is charcterized by fatigue, pessimism, shame, guilt.

• pain signals that something is wrong and must be fixed. SO WHEN SOMETHING IS WRONG WITH YOUR SOCIAL LIFE IT SIGNALS THAT YOUR CHNACES OF REPRODUCTION OR EVEN SURVIVING MAY BE AT RISK.
• crying=social support
• fatigue and pessimism= preventing one from wasting energy  & resources on fruitless endevours.
• they sugested that blocking normal depressive systems could cause chronic negitive life situations, even if the suffer feels better, b/c they will be more likley to loose valuable attachments/persist at unacheivable pursits, less able to learn from mistakes, unable to recruit friends during adverse situations.
• sometimes, we need to feel the pain.