Imagine that your grandchildren can pick exactly how their babies will look, think, and act. Your family curse of breast cancer or cystic fibrosis or early heart attack—not to mention dyslexia, fat thighs, shyness, or male-pattern baldness—will be vanquished in a single stroke. Your great-grandchildren will be as lean, literate, loquacious, and long-lived as their parents want them to be. How does that grab you?
If you think that sounds good, you have plenty of company. More than 40 percent of Americans, according to a March of Dimes survey, think it would be okay to use gene therapy to make their children either more attractive or more intelligent than they were otherwise destined to be. A Gallup poll of British parents found many of them also willing to consider such genetic enhancement, and for some surprising and rather disconcerting reasons: 18 percent to change a child’s aggression level or remove a predisposition to alcoholism, 10 percent to keep a child from becoming homosexual, and 5 percent to make a child more physically attractive.
At the moment, this genetic equivalent of nip-and-tuck cosmetic surgery exists only in the imagination. After nearly a decade of experimentally transferring genes into human beings with serious disease, the practitioners of gene therapy have yet to cure a single person. Moreover, it is still far from certain that the behavioral traits described above will ever be shown to be genetically caused. Still, the controversy surrounding the a...