I.D.

Weaving together the findings of a highly diverse group of scientists - geneticists and psychoanalysts, neuroscientists and primatologists - Winifred Gallagher shows how cutting-edge research is unlocking the secrets of human individuality. It's now clear that we are each born with a certain temperament that pushes some people toward the adrenaline highs of race-car driving, the introspection of the writing life, or the socializing of the campaign trail. This disposition isn't just "psychological," but physiological, too; a unique mind/body identity. But, as I.D. stresses, acknowledging personality's genetic roots makes it all the more imperative that we understand the role played by environment - not only because it's powerful but also because, unlike our genes, we can do something about it. Indeed, science's ancient definition of temperament as inborn is currently being rewritten as new research shows that our life experience can be literally as well as figuratively engraved in our nervous systems, often as emphatically as the marks of genes. We may be born shy or aggressive, but the way in which nurture shapes those tendencies gives us our "second nature.". With stylistic grace, Winifred Gallagher explores the role of heredity and environment in everything from creativity to pathology while preserving the wonder and mystery of being human. Far from making us feel like genetic robots, knowing the facts about our biological and historical legacies imparts a sense of liberation and possibility. We can't completely change who we are, but if we're unhappy, we can make some important adjustment - from turning up or down the volume of a problematic trait to leaving a maladaptive marriage or career - that can feel like a whole new life. When we understand our own I.D.'s and those of our family, friends, neighbors, colleagues, and lovers, our lives become more satisfying and interesting.