Several programs appear to be effective in changing individual adolescents' conflict resolution skills. For instance, in one non-experimental study, delinquent adolescents from twelve families were taught to give positive and negative feedback, accept negative feedback, negotiate, resist peer pressure, follow instructions, and use problem-solving skills (i.e., reciprocal social skills training). The adolescents exhibited increased conflict resolution and negotiation skills at the ten-month follow-up (Serna, Schumaker, Hazel, & Sheldon, 1986).