The nature of our DNA will always lag behind nurture

Gene testing is pointless. Our fates are more likely to be shaped by our postcodes

Genes frighten us, for terrible things have been done in their name. Genes are modern runes - we fear reading in them the ghosts of the past and the future. We fear finding the meaning of life itself if one day they tell us precisely how much we are to blame - did we fail our gifts or overcome the defects allotted us by nature? The double helix is a double-edged sword and we gaze darkly into that twisted thread of life.

Gene-phobia surfaced twice this week, yesterday with the threat of genetic testing for life insurance. Earlier there were the chance remarks of Nobel prize-winner, James Watson, the discoverer, together with Francis Crick, of DNA. A misleading headline in The Sunday Telegraph read "Abort babies with gay genes, says Nobel winner". Needless to say, gay activists and pro-lifers called Watson "outrageous". (In any case, the "gay gene" theory is now scientifically discredited).

Watson is an awkward character so maybe he meant to throw a stone into the gene pool. However, as Richard Dawkins wrote in a letter to The Independent yesterday, what Watson actually said was that women should have a right to abortion for any reason, however trivial. The presence of a gay gene or the lack of a musical gene might be frivolous reasons, but if for whatever crazy reason, a woman decides she does not want the child she is carrying, what is the point of forcing her? Why create a gay child with a homophobic mother? In fact, of course, women very rarely abort frivolously - agonising over the decision even when a foetus has catastrophic defects.

But set aside the abortion issue. There is no point in arguing about it since no one ever crosses the great ideological crevasse that divides the pro- and anti-abortionists. Instead, let us examine the fear of genetic engineering that James Watson unleashed with his remarks. Designer babies!

By the year 2005 every single human gene will have been mapped in the mighty Human Genome Project that Watson initiated. So what if one day we can manipulate human genes? Will we rifle through Harley Street catalogues to assemble our baby of choice? For my daughter, I'll order up an IQ of 180, the voice of Cyndi Lauper, the wisdom of Nelson Mandela, the face of Juliette Binoche, the hands of a sculptor, the heart of a benefactor with side-orders of diligence, wit and cunning. Will people of special talent donate their genes to gene banks? If so, what price a touch of Pavarotti's voice box, Magdi Yacoub's hands, Salman Rushdie's verbal felicities, David Helfcott's piano fingers (but please, not the rest of him)?

Stop there. No more of this. It is all fantastical science-fiction nonsense, the stuff of The X Files and Dark Skies. It is not going to happen. Listen instead to the wise words of Professor Steve Jones, who has just written the introduction to a new edition of Watson and Crick's great work, The Double Helix.

Jones has said it time and time again. Genes do not determine these things. Nurture will always dominate nature. To be sure, some gene defects - like cystic fibrosis - are horribly precise indicators of early death. But intelligence, musical talent? Forget it. Even those genes that show a strong disposition to specific conditions such as heart disease are not predictors. If those who know they are in danger eschew a diet of fried Mars bars they will not die of heart disease.

You want to predict life expectancy? Forget genes, just ask why people who live in London SW7 live 11 years longer than people who live in London E8. A mother wants a rich, successful child? Tell her to marry a rich man, the best possible predictor of the child's future social status.

What of intelligence, likely to be people's first genetic choice? It raises the spectre of a genetic super-class ruling over a genetic under- class. But there is no gene for intelligence, so it will not happen. There are a large number of genes responsible - and even then, according to Jones, nurture wins out. "You want a more intelligent population? Easy, double teachers' pay." It would be a lot cheaper and more effective than genetic manipulation. Why did the average IQ of Japanese children rise by 10 per cent over the past 20 years? Have they been polishing up their genes? No, their schools got better.

Steve Jones talks of the intelligence gene with a special venom. He was brought up in the Wirral, where the byelection is now being fought over the future of grammar schools. That system selected out Jones for grammar school and his destiny as a Professor of Genetics, while his brother, whom he regards as equally intelligent, failed the 11-plus, went to a secondary modern and is now an unemployed bricklayer. That's what tinkering with eugenics does to people - and the 11-plus springs from an essentially eugenic view of humanity. Boosting the education of all will yield far better results than trying to select the right few.

Genes are dangerous when ignorantly interpreted. The insurance industry's trade body yesterday gave a good example of crude abuse. Anyone who has had a genetic test and knows their health prognosis will have to tell their insurers - a short step away from demanding tests for all. Some will become genetically uninsurable while the healthiest will be fought over by insurance companies. But this is not the fault of genetics and the law could fix it by demanding equal insurance rights for all, spreading the risk fairly. The tree of knowledge has always frightened us but Eve was right to eat from it. How we use or abuse that knowledge is in our hands.