The recent news of the successful cloning of an adult sheep-in which the sheep's DNA was inserted into an unfertilized sheep egg to produce a lamb with identical DNA-has generated an outpouring of ethical concerns. These concerns are not about Dolly, the now famous sheep, nor even about the considerable impact cloning may have on the animal breeding industry, but rather about the possibility of cloning humans. For the most part, however, the ethical concerns being raised are exaggerated and misplaced, because they are based on erroneous views about what genes are and what they can do. The danger, therefore, lies not in the power of the technology, but in the misunderstanding of its significance. Producing a clone of a human being would not amount to creating a "carbon copy"-an automaton of the sort familiar from science fiction. It would be more like producing a delayed identical twin. And just as identical twins are two separate people-biologically, psychologically, morally and legally, though not genetically-so a clone is a separate person from his or her non-contemporaneous twin. To think otherwise is to embrace a belief in genetic determinism-the view that genes determine everything about us, and that environmental factors or the random events in human development are utterly insignificant. The overwhelming consensus among geneticists is that genetic determinism is false. As geneticists have come to understand the ways in which genes operate, they have also become aware of the myriad ways in which the environment affects their "expression." The genetic contribution to the simplest physical traits, such as height and hair color, is significantly mediated by environmental factors. And the genetic contribution to the traits we value most deeply, from intelligence to compassion, is conceded by even the most enthusiastic genetic researchers to be limited and indirect. Indeed, we need only appeal to our ordinary experience with identical twins-that they are different people despite their similarities-to appreciate that genetic determinism is false. Furthermore, because of the extra steps involved, cloning will probably always be riskier-that is, less likely to result in a live birth-than in vitro fertilization (IVF) and embryo transfer. (It took more than 275 attempts before the researchers were able to obtain a successful sheep clone. While cloning methods may improve, we should note that even standard IVF techniques typically have a success rate of less than 20 percent.) So why would anyone go to the trouble of cloning? There are, of course, a few reasons people might go to the trouble, and so it's worth pondering what they think they might accomplish, and what sort of ethical quandaries they might engender. Consider the hypothetical example of the couple who wants to replace a child who has died. The couple doesn't seek to have another child the ordinary way because they feel that cloning would enable them to reproduce, as it were, the lost child. But the unavoidable truth is that they would be producing an entirely different person, a delayed identical twin of that child. Once they understood that, it is unlikely they would persist. But suppose they were to persist? Of course we can't deny that possibility. But a couple so persistent in refusing to acknowledge the genetic facts is not likely to be daunted by ethical considerations or legal restrictions either. If our fear is that there could be many couples with that sort of psychology, then we have a great deal more than cloning to worry about. Another disturbing possibility is the person who wants a clone in order to have acceptable "spare parts" in case he or she needs an organ transplant later in life. But regardless of the reason that someone has a clone produced, the result would nevertheless be a human being with all the rights and protections that accompany that status. It truly would be a disaster if the results of human cloning were seen as less than fully human. But there is certainly no moral justification for and little social danger of that happening; after all, we do not accord lesser status to children who have been created through IVF or embryo transfer. There are other possibilities we could spin out. Suppose a couple wants a "designer child"-a clone of Cindy Crawford or Elizabeth Taylor-because they want a daughter who will grow up to be as attractive as those women. Indeed, suppose someone wants a clone, never mind of whom, simply to enjoy the notoriety of having one. We cannot rule out such cases as impossible. Some people produce children for all sorts of frivolous or contemptible reasons. But we must remember that cloning is not as easy as going to a video store or as engaging as the traditional way of making babies. Given the physical and emotional burdens that cloning would involve, it is likely that such cases would be exceedingly rare. But if that is so, why object to a ban on human cloning? What is wrong with placing a legal barrier in the path of those with desires perverse enough or delusions recalcitrant enough to seek cloning despite its limited potential and formidable costs? For one thing, these are just the people that a legal ban would be least likely to deter. But more important, a legal barrier might well make cloning appear more promising than it is to a much larger group of people. If there were significant interest in applying this technology to human beings, it would indicate a failure to educate people that genetic determinism is profoundly mistaken. Under those circumstances as well, however, a ban on human cloning would not only be ineffective but also most likely counterproductive. Ineffective because, as others have pointed out, the technology does not seem to require sophisticated and highly visible laboratory facilities; cloning could easily go underground. Counterproductive because a ban might encourage people to believe that there is a scientific basis for some of the popular fears associated with human cloning-that there is something to genetic determinism after all. There is a consensus among both geneticists and those writing on ethical, legal and social aspects of genetic research, that genetic determinism is not only false, but pernicious; it invokes memories of pseudo-scientific racist and eugenic programs premised on the belief that what we value in people is entirely dependent on their genetic endowment or the color of their skin. Though most members of our society now eschew racial determinism, our culture still assumes that genes contain a person's destiny. It would be unfortunate if, by treating cloning as a terribly dangerous technology, we encouraged this cultural myth, even as we intrude on the broad freedom our society grants people regarding reproduction. We should remember that most of us believe people should be allowed to decide with whom to reproduce, when to reproduce and how many children they should have. We do not criticize a woman who takes a fertility drug so that she can influence when she has children-or even how many. Why, then, would we object if a woman decides to give birth to a child who is, in effect, a non-contemporaneous identical twin of someone else? By arguing against a ban, I am not claiming that there are no serious ethical concerns to the manipulation of human genes. Indeed there are. For example, if it turned out that certain desirable traits regarding intellectual abilities or character could be realized through the manipulation of human genes, which of these enhancements, if any, should be available? But such questions are about genetic engineering, which is a different issue than cloning. Cloning is a crude method of trait selection: It simply takes a pre-existing, unengineered genetic combination of traits and replicates it. I do not wish to dismiss the ethical concerns people have raised regarding the broad range of assisted reproductive technologies. But we should acknowledge that those concerns will not be resolved by any determination we make regarding the specific acceptability of cloning.