This exploratory study provides a foundation for research on socialization in Japanese schools, identifying types of cooperative and competitive student behavior as seen by teachers. The first of two surveys (each using two questionnaires) asked teachers to list examples of cooperative or competitive behavior. The second, designed from the responses to the first, asked a different sample to rank the top 10 of 30 behavior items; through factor and cluster analysis, these items were reduced to composite indexes. Of eight cooperation indexes, six changed ranking between school levels; "harmony" and friendliness were most important overall. Evidently, specific standardized activities foster cooperation, some particular to school level. Though it is unproven that such activities comprise a grand scheme for teaching cooperation, the Japanese school system clearly states goals for socialization. Of nine competition indexes, all changed ranking between school levels; in contrast to cooperative activities, few were sanctioned or formal. Issues raised include, first, the degree to which cooperative and competitive behavior stem from nonschool factors and from explicit or implicit curricula; and second, the interplay and social meaning of cooperation and competition in schools. (MCG)