9.3 genetic and environmental influences on intelligence Flashcards Preview

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Flashcards in 9.3 genetic and environmental influences on intelligence Deck (26)
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IQ scores are most similar for

-identical twins that are identical over fraternal
-identical twins raised apart have a more similar iq score than fraternal twins raised together
-biological siblings raised together is higher than adopted siblings raised together



of IQ scores is bw 40 and 80%
-that means, for any given sample of individuals, about 40-80% of differences in IQ scores originate from genetic differences


the contribution of genetic differences depends on the sample of individuals

heritability of IQ scores for a sample of wealthy ppl is > 70%
heritability of IQ scores for a sample of ppl living in poverty is about 10%


environmental influences

environmental influences will tend to be the dominate influence on any trait whenever there is variation in the environments that host our development


behavioural genomics

have revealed a group of genes that each seem to make a small contribution to our mental abilities


gene knockout (KO) studies

have identified a number of genes related to cognitive abilities in mice
-animals have a gene removed and then compared to animals that did not have that gene removed


transgenic studies

(the insertion of genetic material into animals)
have revealed genes that provide mice with cognitive benefits


environmental influences on IQ scores

many studies of humans and other animals have established a positive link bw mental abilities/brain complexity and the quality of physical and mental stimulation during early stages of development
-rats raised in active and stimulating environments end up with bigger brains that have more synapses


birth order and IQ scores

the 1st born child in a family tends to have statistically higher IQ scores than the 2nd born or 3rd born child
-maybe its bc older siblings often have some responsibility for taking care of their younger siblings and teaching them about things


socioeconomic status and IQ scores

children from wealthier families tend to have higher IQ scores than children from poorer families


socioeconomic factors related to cognitive development

by age 3, children of professional parents have been exposed to 30 million words, whereas children of working class parents have only exposed to 20 million words


a family's wealth is positively correlated with:

the # of books, magazines and newspapers they own their access to computers
and the opportunities they provide for exploring the world outside of the home


a family's degree of poverty is positively correlated with:

lower quality health care/nutrition degree of exposure to toxins stress and conflict inside the home


there is a known association between the quality of a person's or animals diet and

their cognitive development


multiple sources of stress

tend to be more prevalent for poorer families
poorer neighbourhoods tend to be noisier, closer to sources of pollution and toxins, and have much higher violent crime rate and have greater difficulty finding adequate jobs for meeting expenses
financial stress in households causes more conflict among family members


stress directly impairs mental development and functioning

-stress elevates cortisol levels, which impairs cognitive functioning
-stress impairs memory functions at the neurological level
-stress robs mental resources that are essential for acquiring knowledge and skills in school


where does the blame lie for failing to achieve wealth and success ?

easier to blame ppl for their failures than to blame the society that sets some ppl up to for failure and others up for success
wealth is something ppl tend to inherit along with their genes


some ways for enhancing ones cognitive functioning

the N-back task
nootropic substances


the n-back task

the correct response would be to press a button in response to the red-circled display, indicating that the filled in square matches the one two trials ago (the blue circles display)
-evidences suggests that extensive practice on this task provides a boost to peoples IQ scores


nootropic substances

chemicals that are believed to improve cognitive functioning, either indirectly, by boosting alertness and energy levels, through their impact on neurotransmitter levels, or by stimulating the formation of neural connections


Methylphenidate (or ritalin)

inhibits reuptake of norepinephrine and dopamine


modafinil (or provigil)

inhibits reuptake of dopamine


making use of nootropic substances

is not great, since their use often comes with side effects and risks developing a drug dependence


mindfulness meditation

great for your brain
insulates ppl from brain from the loss of grave brain matter that is commonly associated with aging


the flynn effect

our IQ scores now are much greater than the generation before us
some good news about life in the information age


A genetic influence on IQ scores?

twin studies
adoption studies
family studies

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