Many parents don't think twice about straightening their kids' crooked teeth but stop short of fixing a crooked nose, and yet, in just the past seven years, plastic surgery performed on teens has doubled. As for intellectual advantages, parents soak their babies in Mozart with dubious effect, put a toy computer in the crib, elbow their way into the best preschools to speed them on their path to Harvard. Infertile couples advertise for an egg donor in the Yale Daily News, while entrepreneurs sold the sperm of Nobel laureates. I think the answer has to do with the difference between cultivating and purchasing capacities. Buying a Harvard education may enhance a child's natural gifts, he argues, but it's not the same as buying the gifts.
Genetic engineering is more permanent than a pill or a summer-school class.
Parents would be making decisions over which their children had no control and whose long-term impact would be uncertain. If you make a change in one area, it may cause very subtle changes in some other area. Very often when there's a genetic change where we improve something, something else gets hit by it, so it's never a clean thing. The alarmists, like longtime biotech critic Jeremy Rifkin, go further. We may be on the road to programming our own extinction.