...that supports the claim that only "smart" parents have smart children, or that smart parents don't have dumb children, or that dumb parents don't have smart children, and so on.
That would be a silly claim to make. A more plausible claim, and one which is well supported by the evidence, is that smart parents are considerably more likely to have smart children than dumb parents.
That would be a silly claim to make. A more plausible claim, and one which is well supported by the evidence, is that smart parents are considerably more likely to have smart children than dumb parents.
http://en.wikipedia.org/wiki/Heritability_of_IQ