The main purpose of this paper on a study of Indonesian concepts of human nature is to demonstrate practical instances of cooperation between Western and Third World researchers. It is asserted that Western researchers must understand the general views of human nature held by individuals in Third World countries before they can apply theories in these countries. Preliminary studies of individuals' concepts of human nature were conducted in Germany and the United States. Then the concepts of human nature held by 110 young adults in West Java, Indonesia, were assessed using three procedures: (1) an interview concerning values, behaviors, and goals appropriate to adulthood; (2) a presentation of a story involving a character facing a dilemma with moral and social consequences; and (3) a task in which the subject sorted statements corresponding to different developmental levels in the understanding of human nature. Because the first interview procedure involved interactions inappropriate to the culture, the Indonesian coworkers in the research modified the procedure. They also constructed stories that were culturally appropriate to Indonesia and that would correspond to the stories used in Germany and the United States. The sorting procedure was also modified. Eight references are cited. (BC)