Skashion said:
Everything I've ever read indicates there is a fairly substantial link between IQ and genetics. Educate me Damocles. I suppose you could say ultimately that link is unimportant i.e. in the same way that we share 98% DNA with chimps, it's the 2% that matters.
You're getting into pretty dodgy grounds with IQ tests measuring general intelligence, but if we take that as a true presumption for a minute, it still doesn't bear out with most long term quantitative studies. There was a study that I used which shown that although adoptive children had a slight 'IQ lag' with their siblings, it evened out into their twenties so that they were within standard deviations of their intelligence.
Adoptions studies were on way to go in determining the heritability of intelligence, but they have a few variables that aren't properly adjusted for, including the age of adoption and social class of those families adopted into. The ones that did, shown a universally positive response in children normalising to the same IQ as their siblings.
Anyway, more on the genetics front, it has long been a dream of geneticists to find an 'intelligence gene', but despite many different studies across different ages groups, different IQ groups, different social groups, etc, nothing has ever been found that is shared any more than statistically likely.
There are various genetic disorders to cause retardation, but none that seem to create above average intelligence.
EDIT: Sorry mate, did you want to read the studies or just a general reply?