PSYC12H3S Lecture 7
Stereotype threat I
Movie: Testing and intelligence
IQ test shows ur position of intelligence within ur society. How u differ in ur abilities, behavior and
personality matters. There are many tests taken to predict the future performance of the person. The IQ
test has to be reliable or else it will be invalid testing. Stereotype threat can affect a person performance
during a test. The testing is complicated but yet important.
Male-Female Math Performance Difference
Graph: The data reveals from young age to adulthood; adult women r declining in their math performance
and men r only going higher in their math performance.
Black-White IQ distribution
Graph: Based on IQ test that may be bias and may not predict things. The main point is the curves largely
overlap but we see a difference favoring whites than blacks. These r averages and we cannot tell anything
about anyone but we can only place ppl based on their scores in that graph.
Ask yourself about group differences in “intellectual performance”
Race: Black-White IQ difference
Sex: Male-Female math difference
SES: Rich-Poor IQ difference
Why are groups different?
Question: Why groups differ in intellectual performance? Different socializing environments.
Origins of Intelligence?
When we think of intelligence we think of nature (environment) and nurture (what u learned).
Intelligence is highly heritable
High correlation between parent IQ and child IQ
IQ of identical twins is highly related; more than fraternals
IQ of identical twins reared apart is highly related
IQ of adopted children is related to IQ of biological mother, less related to IQ of adopted mother
If u have smart parents likely u will be smart and bc u r then so r ur siblings. The correlation between IQ
and child IQ is high. Bc they share the same environment and can be said it is not necessary inherited. IQ
of identical twins can bring the argument that IQ is in fact inherited. These r not great bc they live in the
same environment. Rearing apart of twins and adopted children shows that IQ is indeed inherited. Environment
Environment also plays role
IQ of identical twins reared apart is less related than IQ of identical twins reared together
IQ of fraternal twins is more strongly related than IQ of regular siblings
IQ of adopted children is more similar than unrelated individuals reared apart
Impoverished environments related to lower IQ
If compare the difference of reared apart and reared together we see that reared apart is less related. IQ of
fraternal twins is more strongly related to regular siblings bc they do things almost always together. All
these tests show that environment plays an important role. Poor individual have lower IQ when they r still
in their environment so r the rich idividual, therefore the environment plays a big role.
Nature vs Nurture?
Both Nature and Nurture contribute to intelligence
But genetics certainly play role
Heritability index = 0.50 (may be as high as 0.65)
If within-group difference has genetic component, perhaps between-group difference has genetic
No. Between-group differences may be caused by different factors than within-group difference
It seems genetic plays a role in intelligent generally. If 50% is determined by genes, can we say that the
difference of man and woman intelligence r bc of genes?
Within vs. Between Group Differences
Seed: the height of plant is determined by the quality of the seed. The seeds r mixed and not has good
seed at the top and bad at the bottom. Now the soil good and bad soil, we see differences in how high the
plants grow, this is entirely due to genetics the seeds quality. But we cannot just predict that the difference
of the plants is bc the genetics bc there r other factors that is in play here like soil quality.
Why are groups different?
A: Not different
B: Tests are unfair
C: Different socializing environments
Eliminate “not different” bc of the seed analogy.
Does the difference exist?
“Intellectual performance” (whether biased or not) reveal robust differences.
What does this difference mean?
Example of date black n white IQ: There is rapid change that is predicted here and points to the affect of
environment since genetics changes in very slow paste.
Are the tests unfair? The tests are culturally biased
External bias: does this thing predict anything for ppl and does this predict something for different
groups. Internal bias: the content of the test itself; the following i-clicker questions can be bias in way that
only those who r in that environment can answer.