Our lives written in the genes

In the mid-1990s, geneticist Dean Hamer's claim to have isolated a "gay gene" earned world headlines. Now Hamer, chief of gene structure and regulation at the United States National Cancer Institute, is offering his how-to guide for a brave new genetic era, co-authored with a Washington journalist.

In his new book, Living With Our Genes Hamer argues that genes that define behaviour are now being discovered by scientists. Genes may mould us mentally as adventurous "novelty-seekers" or cautious "harm-avoiders"; they fashion our sex lives and even determine our happiness.

In Hamer's book, consulting your genes is akin to reading the daily horoscope. When it comes to choosing a life partner, making career choices, raising children, or having sex - think D4DR. It is a gene that Hamer and others have linked to the human trait of "novelty seeking", in people who are physically, intellectually, or sexually adventurous.

If your spouse is oozing the "long form" D4DR, and you are not, there is trouble in store. If you fall in love with a thrill-seeker, just remember it is in his genes. "Get rid of the illusion that you can change him or imagine that he will mellow with age," Hamer advises. "If he wants to bungee jump, pack his lunch and double his life insurance I Remember that what attracted you to this person is the same thing that drives you crazy."

The flip side of thrill-seeking is a trait called harm-avoidance, often manifested as shyness. The existence of inherited "life-time" shyness has been confirmed many times by researchers, Hamer writes, tied to a more active right side of the brain, and bigger increases in heart rate under stress.

Queen Victoria and Dwight Eisenhower were probably low on novelty seeking: prudent, reflective, and orderly, adventurous they were not. A high novelty person would tend towards work as a pilot, firefighter or stock broker. Low novelty persons tend to be accountants, librarians, machine tool operators, dentists and computer programmers.

Tim Cornwell Living with Our Genes: Why They Matter More than You Think, Doubleday, $24.95