Thus, we should always be alert to individual and personal developmental differences. Part of this understanding may well come from an increased self-awareness. It is difficult to achieve this only from textbooks, lectures, movies, and supplementary readings. Rather, it seems to come primarily through the very personal acts of living and experiencing which are themselves our subject matter. While wisdom of this sort is difficult to obtain, one part of wisdom seems to be a tolerance and understanding of cultural and individual differences or diversity.
People are the subject matter of all courses in human development.