Throughout the ages and in every culture, people have used the seasons as a metaphor to mark life's transitions and to help understand the purpose and meaning of our mortal journey. In the last few decades, there has been an astonishing growth in our knowledge of human development through the entire life span; at the same time, there has been dramatic change in the timetables of our lives. Seasons of Life, a companion book to the acclaimed PBS television series, interprets the fascinating work and discoveries of hundreds of social scientists and, through the personal stories of dozens...