In the 1940s, Sheldon and Eleanor Glueck of Harvard Law School began a cross-sectional study of 500 delinquent and 500 non-delinquent boys. This book is based on interviews and other data provided by 240 subjects in the non-delinquent group over a 40-year period. All of the subjects were born into lower- and working-class Boston families in the 1920s and 1930s and were interviewed at an average age of 14, 25, 31, and 47, with subsequent questionnaires administered through the 1980s. Chapter 1 serves as an introduction and presents the theoretical framework of the study, which is based on Erik H. Erikson's idea of "psychosocial generativity"--that is, that an adult's caring activities create or contribute to the life of the next generation. Chapters 2, 4, 6, 8, and 10 report on 5 empirical, quantitative studies that focus on the subjects' role as fathers compared to: (1) the varieties of paternal generativity; (2) their midlife marital, work, and social success; (3) their children's early adulthood accomplishments; (4) their ability to deal with infertility; and (5) their boyhood experiences. Chapters 3, 5, 7, and 9 report individual case studies of 4 of the 240 men, focusing on their role as parents and their relationship with their children. The main conclusions of the work, presented in chapter 11, are that fathers play a vital role in their children's lives, especially in the realms of social-emotional, intellectual-academic, and physical-athletic development. Contains approximately 500 references. (MDM)