In the present study, second-year high school students were asked about their reasons of having a rival or no rival in their school life. Factor analysis found four factors for reasons of having a rival: mutual stimulation, target, closeness, and intellectual parity. Factors for not having a rival were three: self-orientation, indifference, and avoidance. Rivals were categorized into three: standard, target, and good match, and two axes of partner similarity and mutuality were extracted from discriminant analysis with the four factors of having a rival as predictors. Having a rival who is a good match is predicted by both high partner similarity and mutuality. A "target" rival is associated with low partner similarity, and a "standard" rival, high partner similarity but low mutuality. These results were discussed in the context of social comparison theory and self-evaluation maintenance (SEM) model.

Key words: rival, rival type, competition, social comparison, self-evaluation maintenance model