This action research project evaluated the impact of a program for enhancing interpersonal problem-solving skills on academic achievement in elementary students in an industrial, urban Illinois community. The lack of social skills and inability to think critically were documented through office referrals and teacher observations of kindergarten, first grade, special needs, and reading classes. The resulting intervention consisted of: (1) a peer mentoring program in which students in grades 4 to 6 were trained as mentors for teaching social skills, conflict resolution, and critical thinking; (2) cooperative learning activities to enhance student engagement, active listening, turn-taking, appropriate behavior and voice volume, and use of "happy talk"; (3) conflict resolution activities and children's literature to build a positive classroom climate and deal effectively with conflict; and (4) training in critical thinking, including categorizing, brainstorming, questioning, drawing conclusion, sequencing, and evaluating. To assess the effects of the intervention a pre- and posttest were given to check for appropriate social behavior, and teacher journals and checklists were kept throughout the intervention period. Findings indicated an increase in student critical thinking skills, an improvement in interpersonal skills, and an increase in the use of conflict resolution skills. The amount of time spent teaching social skills and conflict resolution increased throughout the intervention. (Nine appendices include data collection instruments and sample classroom materials. Contains 63 references.) (KB)