The years between 18 and 50 are the center of life, a time of growth and opportunity. But until now no guide has existed to help us understand the mysterious process by which we become adults.

Studies of child development have plotted every nuance of growth and given us comforting labels such as the "Terrible Twos" and the "Noisy Nines." Yet what Gesell and Spock did for children hasn’t been done for us adults. Whenever psychologists do address themselves to adult life, it is in terms of its "problems" – rarely from the perspective of continuing changes through the life cycle. But now a new concept of adult development has begun to emerge.

Gail Sheehy, an author those investigative reporting has won numerous prizes, set herself three objectives in writing this pioneering book: to locate the personality changes common to each stage of life; to compare the developmental rhythms of men and women – which she found strikingly unsynchronized; and, in light of this, to examine the crises that couples can anticipate. Which passages cause one partner to put an extra strain on the other? How do their needs and drams change with age?

Drawing on three years of painstaking research and 115 in-depth interviews, Gail Sheehy goes beyond the academicians to reveal both the internal and external forces acting on all of us. This humane, widescreen view of adulthood speaks eloquently to men and women, to couples and singles, to "wunderkinds" and late bloomers, to careerists and homemakers. It is the only book that brings together a coherent vision of the passages we must all take through the Twenties, Thirties, and Forties toward what is potentially the best of life.