The transition to adulthood has been studied for decades in terms of transition events such as leaving home, finishing education, and entering marriage and parenthood, but only recently have studies examined the conceptions of young people themselves on what it means to become an adult. The goal of this volume is to extend the study of conceptions of adulthood to a wider range of cultures. The chapters in this volume examine conceptions of adulthood among Israelis, Argentines, American Mormons, Germans, Canadians, and three American ethnic minority groups. There is a widespread emphasis across cultures on individualistic criteria for adulthood, but each culture has been found to emphasize culturally distinctive criteria as well. This volume represents a beginning in research on cultural conceptions of the transition to adulthood and points the way to a broad range of opportunities for future investigation. This is the 100th issue of the quarterly report New Directions for Child and Adolescent Development.