psych 2aa3- oct 24th Flashcards
what trait of COGNITION is highly heritable
executive function
why is executive function seen as highly heritable?
- parents and offspring have similar executive function
- monozygotic twins have higher correlations than dizygotic twins
is cognition influenced by environment? how/provide an example
yes, physically fit children performed better at allocating attentional resources
what is the heritability of intelligence like?
mostly indirect (passive, evocative, and active effects)
what are the passive effects for how genes effect intelligence like?
passive effects: parents genes dictate how parents behave towards their children and the kind of environment they provide
what are the evocative and active effects of genes on intelligence?
evocative effects: children’s genes dictate how others respond to them and which environments they choose (evocative and active effects)
why did high SES correlate to higher IQ?
SES is dependant on the home environment (value of education), friend selection, neighbourhood income, academic expectation, and academic opportunities
How do children who experienced perinatal stress get effected?
they experience a greater effect being low SES
how much is the estimate of heritability and intelligence?
50%
Why is the correlation between heritability of intelligence 50%?
adoption studies have shown that there is no genetic relationship between parents and children, similarities are due to environment whereas twin studies have revealed that monozygotic twins are more similar that dizygotic twins so there is some influence genetic influence
How important is prenatal environment for intelligence?
It is more important than previously believed.
So, what is the bottom line on intelligence? what effects it?
both environment and genetics (roughly 50/50 based on studies)
what was the paradoxical adoption study results?
- average IQ of African American children adopted into white middle class families was 20 points higher then comparable African American children who were not adopted
- however, correlation was higher between children and their biological mothers (r=0.43) then with adoptive mothers (r=0.29)
what did the paraodixal adoption study reveal about correlation?
correlation does not tell us about the value of a variable but only reveals the relationship between the two variables
what was the experiment used to determine the influence of early experience?
the rat-cage experiment
what was the rat- cage experiment?
rats were raised in 3 different environments, normal cage, a cage with activities, and a stove pipe. the rats were in 4 groups, ranging from 30-75 days (children) and 75-120 days (adult) and had to solve a maze
what were the results of the rat-cage experiment?
most errors: stovepipe–>free
second most errors: normal cage
2nd least errors: free to stovepipe
least errors: free environment
what do the results of the rat-cage experiment show?
early experience/environment is very important because the stovepipe rats in early development made the most errors. In addition, the rats who got a free cage in early development made the 2nd least few errors
What is lower iq associated with?
Lower iq associated with low SES, lac of stimulating play materials, and unresponsive parenting (not responding appropriately to individuals behaviour)
What is the cumulative deficit effect
as the number of risk factors increase, IQ decreases (but need a good build up, just 1 risk factor wont have a significant effect)
What happened in Romanian orphanages?
to increase the population, people gave birth and placed them in orphanages that had horrible environments (eg: abuse, overcrowding)
what were the physical and cognitive effects of the Romanian orphanages?
physical: decreased height, weight, head circumference
cognitive: lowered IQ (in range of intellectual disabilities)
What were the effects in the brain from the orphanages
reduced cortisol activity in prefrontal cortex (executive function), temporal lobe, hippocampus (memory), and amygdala (emotions) and less white matter (myelination) in pathways between limbic system and frontal lobe
is there plasticity in the effects of orphanages (is it reversible)?
yes, it is reversible, children who were removed from the orphanages within first 2 years of life had normal developmental outcomes
is prefrontal cortex only important for intelligence?
No, efficiency of processing in neural pathways could be more indicative of intelligence
why are the differences between low and high performative vs verbal individuals?
for performative, there was no difference in cortisol thickness, only verbal iq had a difference
what was the pattern found in low vs high verbal IQ people?
significantly greater correlation strength in thickness in low verbal iq people (thickness in one area would predict thickness in another area)
what areas of the brain did verbal iq people have significantly strong correlation strength?
bilateral tamporal, inferior frontal, and lateral partial regions
is cortisol thickness important for intelligence?
people with superior intelligence had cortisol thickness until 11 years old (even though it was thickening by less and less). high/average interest had less thickening in the initial years.
where are the differences in cortisol thickness between average and superior IQ youth?
Frontal lobes
