This study investigated the relative effects of two reinforcement orientations and two success-sharing conditions on social isolation of preschool children. The two experimental factors were operationalized as game-like activities: (1) a “Good-Friends” game that consisted of two reinforcement orientations, the isolate-oriented vs. peer-oriented reinforcement conditions and (2) a “Magic-Box” game that consisted of two success-sharing conditions, the sharing vs. non-sharing of success.