Lecture 19- Heritability and Racial Differences and Bell Curve Fallacy
The Bell Curve: Intellegence and Class Structure in American Life
- There is a genetic basic to the IQ of different races in the US
Why is this relevant?
- Then there is no point in throwing out money because no variation in environment will change
their IQ – Racist!
- Race, Evolution, and Behaviour
- Average difference in IQ from different races account for genetic differences
IQ is heritable BUT that is not the same as saying that it is heritable
- Bad science – comment towards Rushton book
Heritability of IO and the Bell Curve
- Facts: 1. IQ is heritable and 2. There is a difference between IQ of African Americans and
- In the book they conclude that environmental difference is not big enough to cause this change
so it must be due to heritability race.
- There is no debate that: 1. IQ is affected by environment and white and black people have
different populations and different environments.
Hernstein and Murray’s Argument
- Fact: difference between IQ of black and white people
- Fact: IQ heritability is 60%
- Now if genetic variation is removed, then the graphs would look like this
- And so what is left is just what is due to environmental variation
- Conclude: that the difference in quality of environment for black vs white is not large as shown
in graph (15 points)
- So they conclude that it is due to genetic difference
- You cannot decide to trim 60% of genetic variation – and they just trimmed it from the tails
which suggests that they planned their results.