On Nov 20, 2007, at 2:40 PM, Miles Jackson wrote:
> I share Doug's disgust for this shit; however, one link of his
> "chain of
> illogic" is in fact well supported by research: the heritability of IQ
> performance. Based on twin and adoption studies, the heritability
> ratio
> for IQ performance is .40 to .60, meaning about half of the
> variation in
> IQ scores can be attributed to genetic variation.
If true - and as I recall there are plenty of problems with twin studies (e.g., how early were they separated, and how different are the environments they were raised in) - then the fact that you can explain just 50% of the variation in IQ between creatures sharing identical genetic material is really underwhelming. And of course that all has little meaning for comparing populations.
Doug