egoThe entire human genome has been read. Even ten years ago, that seemed a distant goal; but last month, scientists announced that they have completed reading a “rough draft” of the complete recipe for a human being. It will soon be available on compact disc for anybody to read: a book 800 times longer than the Bible. This breakthrough will open an amazing world of possibilities for medicine-including the prediction, prevention, and treatment of many diseases, from kidney stones to cancer.

But why stop at disease? Instead of merely eliminating the negative, why not accentuate the positive-by tinkering with the text to improve it? After all, in pursuit of the perfect human being, we have willingly tried every weapon that falls into our hands, from prayer to psychoanalysis to breast implants. Will we-and should we-do the same with genes?

It is fashionable to answer that we should not, that we probably nonetheless will, and that that would be a disaster; I am more sanguine. Genetically modified people will not pose a great threat to society, even if we choose to create them; but we will, on the whole, not choose to create them, so there is little to worry about on this score.


Discussions of these issues are burdened by a complicated history. A century ago, progressive social reformers were obsessed by the new agenda of “eugenics.” There was a sense of urgency in their desire to improve the human race by selective breeding. It had worked well enough in cattle and chickens, but we human beings were not only failing to breed from the best specimens; we were allowing the worst to have the most children.

“Some day,” said Theodore Roosevelt in 1910, “we will realize that the prime duty, the inescapable duty, of the good citizen of the right type is to leave his or her blood behind him in the world.” In the same year, Winston Churchill lobbied for compulsory sterilization of the mentally handicapped: “I feel that the source from which the stream of madness is fed should be cut off and sealed up before another year has passed.”

Britain never did pass such a law, thanks to determined opposition from a libertarian member of parliament named Josiah Wedgwood. In America, however, states began to pass laws allowing mandatory sterilization. In 1927, the Supreme Court upheld Virginia’s eugenic-sterilization law in Buck v. Bell. Carrie Buck, whom the state wished to sterilize, lived in a colony for “epileptics and the feeble minded” in Lynchburg, with her mother Emma and her daughter Vivian. After a cursory examination, Vivian was declared an imbecile-she was six months old at the time!-and Carrie was ordered sterilized to prevent her from bringing more imbeciles into the world. Supreme Court Justice Oliver Wendell Holmes thundered that “Three generations of imbeciles are enough!” Compulsory- sterilization laws were thenceforth upheld in many states; more than 100,000 Americans were sterilized under them.

The tragedy of that story lies not in the science behind eugenics, but in the politics: It is the coercion that was wrong. An individual who volunteers for sterilization is doing no harm, whatever his or her motives; one who orders another to be sterilized against his or her will is doing wrong. It is that simple.

The eugenic movement began with the best of intentions. Many of its most strident advocates were socialists, who saw eugenics as enlightened state planning of reproduction. But what it actually achieved, when translated into policies, was a human-rights catastrophe: the rejection of many immigrants, the sterilization of many people whose only crime was to have below-average intelligence, and eventually, in Germany, the murder of millions of people.

But now, a century later, we are once again practicing a sort of eugenics: We abort fetuses that would be born with Down syndrome or inherited disorders. In New York, Ashkenazi Jews who carry the Tay- Sachs mutation can avoid marrying each other through blood testing organized by the Com mittee for the Prevention of Jewish Genetic Disease. We also stand on the brink of cosmetic genetic engineering.

Are we simply repeating the mistakes of the past? No. The principal difference is that whereas eugenics, as conceived in the early part of the 20th century, was a public project, modern genetic screening is a private matter. Only China still preaches eugenics for the good of society; everywhere else, modern eugenics is about individuals applying private criteria to improve their own offspring by screening their genes. The benefits are individual, and any drawbacks are social- exactly the opposite of the old eugenics.

Another difference is precision: The selective breeding of the past worked slowly and unpredictably-but today, we can insert a gene into an organism and be all but certain what the effect will be: For example, inserting the genetic phrase “Make insulin!” into a bacterium transforms the life of a diabetic.

Genetic engineering of plants and animals is now routine. Only the genetic engineering of human beings is forbidden.

It would work: Of this, there is no doubt. Take a simple example: the gene on chromosome 4 that is associated with Huntington’s disease, a terrible mental affliction of middle age. You could go into the gene in a fertilized egg, find the crucial phrase “CAG”-which, in affected people, is repeated more than 39 times in the middle of the gene-and remove about half of the repeats. It would not be easy, but it could probably be done. The result would be a healthy person with no risk of Huntington’s, and no risk of passing it on to her children.

pigdThis procedure might become a neater and less intrusive option than the three now available: 1) screening followed by abortion-the course of action followed by many couples who find themselves carrying a child with a devastating disease; 2) pre-implantation genetic diagnosis, which is in vitro fertilization followed by implantation of a healthy embryo and rejection of one that carries the faulty gene; and 3) gene therapy, the immensely difficult and dangerous procedure of trying to infect sufficient cells in your body with a gene-carrying virus to correct the faulty gene.

It is not just medical genetic engineering that is feasible; cosmetic genetic engineering could also begin tomorrow, though it would still be very primitive. There is a gene on chromosome 17 called the ACE gene, which comes in two equally common varieties, long and short. On average, people who inherit two long ACE genes (one from each parent) are better athletes than people who inherit two short versions. For instance, of 123 British-army recruits, the long-gened ones improved their weight-lifting ability much faster during training than the short-gened ones.

It would be comparatively trivial to engineer a human embryo so that it had two long ACE genes. The result would be a child slightly more likely to win long-distance running races. There would be no risk of unpredictable consequences, because about one in four of us have two long ACE genes already; it is not unnatural. It would not be cruel to the child, and it would have no consequences for society. But should it be allowed?

Everybody-from scientists to theologians-seems to agree that human genetic engineering is wrong. Their reasons are a mixture of respect for the sanctity of life and fear of the unpredictable. But if they were ever to relent and allow it, it would be for medical, not cosmetic purposes. To correct a cruel inherited disease-like Huntington’s-is one thing. To use the same technology to correct a subjective defect-non- blue eyes or short stature-would be quite another.


Yet even at this “easy” end of the spectrum, there are uncomfortable questions. Cures might seem uncontroversial, but they are not. My colleague, the sociologist Tom Shakespeare, is achondroplasic, but he regards his inherited short stature as a disability only to the extent that society imposes that prejudice on him. With a first-class degree from Cambridge University and a good career, he does not see his genetic disorder as a reason for eliminating future people like him.

He sees genetic engineering as undermining society’s respect for people like him, because it sends the message that disability could be-and therefore perhaps should be-eliminated. In a genetically engineered society, the parents of a genetically disabled child would feel social opprobrium for not having “done something about it.”

I see his point, but I do not fully agree with it, for the following reason: I see nothing in history to suggest that the ability to cure a condition lessens compassion or respect towards its sufferers. Indeed, society’s respect for people with “preventable” disabilities has surely never been greater than now:People with Down syndrome, for example, were once abandoned or shunned; they are now treated with much more respect.

I suspect it will prove impossible in practice to draw a line between cure and enhancement, between medical and cosmetic genetic engineering. One person’s cure is another person’s enhancement. Is an inherited weight problem a disease? Would it be a cosmetic enhancement to “cure” dyslexia?

Assume that one day, genetic alleles that predict homosexuality are discovered-a wild assumption, but not inconceivable. To a heterosexual couple, disabling the “gay genes” in their potentially homosexual child might seem like a “cure” that prevents an “abnormal” life. But if so, then for a homosexual couple trying to procreate through a surrogate mother, disabling the “straight genes” in their child might also seem to be a “cure.”

James Watson famously remarked a few years ago that if a mother, following a prenatal diagnosis, wanted to avoid having a gay child, that was up to her. After all, more than 95 percent of abortions are carried out for the convenience of the mother and are of “normal” fetuses. It was hard for Watson to see who else should be allowed to make the decision on her behalf: “These things should be kept away from people who think they know best . . . I am trying to see genetic decisions put in the hands of users, which governments aren’t.” This led to a predictably hysterical headline in a British newspaper: “Abort gay babies, says Nobel prize winner.” Note the misleading use of the imperative tense: Watson was arguing against coercion, not for it.

Another objection to genetic engineering is that it would drive out diversity, as people converge on the “ideal.” Again, I think this argument is mistaken. Far from threatening diversity, genetic engineering may actually increase it. Supposing cosmetic genetic engineering became accepted, musical people might seek out musical genes for their children; athletes might seek athletic genes; etc. It is very unlikely that everybody would choose the same priority.

If diversity is not threatened by genetic engineering, then another argument-that in a genetically engineered world, there would be an underclass of those who could not afford the procedure-also evaporates. In this scare scenario, the rich might buy themselves an even better start in life with the best genes. But this argument applies only if genetic engineering becomes commonplace, and it is at least partly undermined if everybody is using different criteria of perfection. After all, just by choosing our marriage partners we have been practicing private eugenics ever since we became human: Dark good looks, a slender figure, a winning personality, or a quick mind-in considering these attributes in potential mates, we are, at least partly, selecting genes. Yet diversity is not threatened, because each of us has different criteria.

When artificial insemination was first thought of, in the 1930s, a prominent Nobel-prize-winning American geneticist, H. J. Muller, wrote a book speculating about the uses to which such a technique would be put. “How many women,” he wrote, “in an enlightened community devoid of superstitious taboos and of sex slavery, would be eager and proud to bear and rear a child of Lenin or of Darwin! Is it not obvious that restraint, rather than compulsion, would be called for?”

Well, no, it is not obvious. Attempts to make test-tube babies “eugenic” by establishing banks of sperm from clever men, or of eggs from beautiful women, have largely failed. People use in vitro fertilization (IVF) to have their own children, not to have other people’s-let alone Lenin’s. IVF is actually an instructive precedent for the current debate: When it was invented in the 1970s, society as a whole largely disapproved, finding the procedure unnatural and abhorrent. It gained acceptance because mild disapproval by the many was matched by fierce demand from the few; it took off because infertile individuals demanded it, not because society as a whole decided they could have it. It was an individual decision, not a collective one.

Just as infertile people demanded access to IVF, even before it had been fully tested for safety, it is possible that people who carry fatal genes will demand access to genetic engineering; but this is not very likely. Unlike infertile people, they already have an alternative: pre-implantation genetic diagnosis, which can spot and discard affected embryos in favor of unaffected ones. And if these people, for whom a “bad” gene is the difference between misery and happiness, do not need genetic engineering, why would anybody else need it? It is true that a few people might wish for a blue-eyed boy, but would they really be prepared to abandon the easy business of natural conception for a painful and exhausting test-tube conception instead?

My point is that cosmetic genetic engineering would attract a very small-and probably half-hearted-clientele, even if it were made legal and safe. I simply cannot think of a single feature of my own children that I would have liked to fix in advance. People do not want particular types of children; they just want their own children, and they want them to be a bit like themselves.

When faced with a mediocre hand at poker, you change some cards and start again. But when faced with perhaps 40,000 human genes, any of which you could change for what may or may not be a slightly better version, which would you change? Looks, intelligence, talents, skin color? It doesn’t sound so tempting, does it?

The history of eugenics teaches that nobody should be forced to engineer her children’s genes-but, by implication, neither should anyone be forced not to. To regulate such decisions with heavy-handed state intervention would be to fall into the very trap that caught the do-gooder eugenicists of 1910. I am not against all regulation: At the very least, governments can step in to ensure standards among practitioners (something they are quite good at). But they would be unwise to try to specify in detail what people can and cannot decide to do for themselves. As Thomas Jefferson said: “I know no safe depository of the ultimate powers of the society but the people themselves; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion.”

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