Nature vs. Nurture: Reaction to the Twin Studies

This was the first time I'd been introduced to the twin studies and I found them very interesting and also very germane to the debates surrounding genetic modification. Stock uses these studies in his quest to explore what kind of genetic modifications might be possible or probable, but I find their results to have more impact on the questions of equal opportunity, as addressed in a previous entry. To wit, if genetics and environment play approximately equal roles in talent and abilities (IQ was listed as being 45 to 75% attributable to genetic makeup) How does that impact the discussions about leveling the playing field? Say we consider a genetic lottery and a cultural lottery. (These concepts are used in a couple of our readings) Every child is born with a roll of the both dice. He could be born with great genetic gifts but an environment of terrible poverty, or be born "genetically unfortunate" but have all the opportunities that his parents' money can buy. If we buy into the third form of equal opportunity where the playing field must be leveled to account for deficiencies in the child, we now must figure out which deficiencies we level the field for. If the child is of above average intelligence, but due to upbringing, can't read, is it fair to genetically enhance him to make up for the inequities of the more challenging environment? The same question could be asked about athletic prowess, attractiveness, or any number of other traits that are affected both by genetic makeup and environment.