"Each of us is born into the world as someone; we spend the rest of our lives trying to find out who," says Hamer, whose lab at the National Cancer Institute made headlines when it discovered a genetic link to male homosexuality, and went on to discover genes for two other personality traits: thrill-seeking and worry.

While there is no denying our genes, says the renowned geneticist, an individual's personality is made up of two distinct components: temperament, which comes from genes, and character, which is acquired. To explain the complex interplay between the two, the book devotes a chapter each to eight genetically linked traits-worry, thrills, anger, addiction, sex, thinking, hunger, and aging.

Using many case histories-including twins raised apart and individuals who've been studied at every stage of their lives (we see an unhappy baby become a depressed adult), the authors decipher the mysteries of inherited traits.

Genes may, as the subtitle holds, "matter more than you think," but researcher Hamer and his writing collaborator reassure that genes are not all that matter. He and Copeland are concerned with the nature side of the perpetual nature-nurture argument over human development yet stress that nurture remains influential. . . . Excellent popular science writing that ought to grab plenty of attention. -- Booklist

For those more interested in reality as opposed to ideology and fantasy, this will be an exceptionally interesting and useful book. -- E. O. Wilson