Camp leadership programs have the potential of improving important psychosocial factors in teens who might eventually become counselors. Accepted behavioral theory might increase understandings of those changes so program training architectures can be improved. As part of larger-scale longitudinal research, participants (N = 129; 64 % female, Mage = 14.6 years, SD = 0.6) were selected by senior camp administrators for a structured leadership training program that required in-person conferences, viewing training videos every 2 weeks, obtaining ongoing mentoring from senior camp staff, and attending several weeks of summer camp where further training was provided. Validated surveys of proposed dimensions of self-control and interpersonal functioning were administered twice over 6 months to assess training program-associated changes. There were significant improvements in total self-control, self-control specifically related to coping, and family-related functioning. Although no demographic factor was associated with score change, baseline score was a significant predictor across measures. After controlling for baseline scores, stepwise multiple regression analyses indicated that higher self-control scores (i.e., planful behavior, coping efficacy, affective thought management) significantly predicted improvements in general, family, and peer-related functioning. Theory-based relationships between changes in self-control and interpersonal functioning enabled the identification of training program areas that might be targeted for improvement.