抄録
Elaboration of understanding the concept of “justice” by developmental psychologists was addressed by focusing on the importance of developmental perspectives in understanding human behavior. Mainstream developmental theory has changed from stage theories to domain theories. Currently, the development of justice is considered to be a multi-dimensional process. Similar to other moral concepts, people understand justice differently in different contexts. A concrete example of a study on “majority voting” and “freedom of speech” that was conducted in Japan is presented. Although this study was limited to “how the sense of justice is developed,” the ultimate task of research on moral development is to explore the question; “why the sense of justice developed.” It is suggested that this should be the goal of future research.