Dabrowski's ideas about personality development are not only a source of practical recommendations for assisting the development of persons of varied age but can also be an inspiration for research. The theory is exceptionally helpful in describing developmental phenomena. Cases of multilevel development were studied in autobiographies of 7 participants. Research results not only confirm the basic assumptions of the theory but are a fitting point of departure for further investigations of human development. This study showed that the beginnings of positive disintegration could be traced to between ages 5 and 7. In addition, an understanding adult plays a key role in the transition from unilevel to multilevel development, and religion and art play a significant role in multilevel development.