Moral psychology is a field of study in both philosophy and psychology. Historically, the term "moral psychology" was used relatively narrowly to refer to the study of moral development. Moral psychology eventually came to refer more broadly to various topics at the intersection of ethics, psychology, and philosophy of mind. Some of the main topics of the field are moral judgment, moral reasoning, moral sensitivity, moral responsibility, moral motivation, moral identity, moral action, moral development, moral diversity, moral character (especially as related to virtue ethics), altruism, psychological egoism, moral luck, moral forecasting, moral emotion, affective forecasting, and moral disagreement. Today, moral psychology is a thriving area of research spanning many disciplines, with major bodies of research on the biological, cognitive/computational and cultural basis of moral judgment and behavior, and a growing body of research on moral judgment in the context of artificial intelligence. History The origins of moral psychology can be traced back to early philosophical works, largely concerned with moral education, such as by Plato and Aristotle in Ancient Greece, as well as from the Buddhist and Confucian traditions. Empirical studies of moral judgment go back at least as far as the 1890s with the work of Frank Chapman Sharp, coinciding with the development of psychology as a discipline separate from philosophy. Since at least 1894, philosophers and psychologists attempted to empirically evaluate the morality of an individual, especially attempting to distinguish adults from children in terms of their judgment, but these efforts failed because they "attempted to quantify how much morality an individual had—a notably contentious idea—rather than understand the individual's psychological representation of morality". In most introductory psychology courses, students learn about moral psychology by studying the psychologist Lawrence Kohlberg, who proposed a highly influential theory of moral development, developed throughout the 1950s and 1960s. This theory was built on Piaget's observation that children develop intuitions about justice that they can later articulate. Kohlberg proposed six stages broken into three categories of moral reasoning that he believed to be universal to all people in all cultures. The increasing sophistication of justice-based reasoning was taken as a sign of development. Moral cognitive development, in turn, was assumed to be a necessary (but not sufficient) condition for moral action. But researchers using the Kohlberg model found a gap between what people said was most moral and actions they took. In response, Augusto Blasi proposed his self-model that links ideas