Series of experiments in which boys from intact, middle-class families who were carefully screened to ensure psychological normalcy, and put in a summer-camp setting where the counselors were actually researchers. Social groups were created which subsequently came into conflict with each other. In stage one, group formation, members of the groups got to know one another and developed social norms for their group in which leadership and structure evolved. In stage two, group conflict, the now-cohesive groups came into contact with each other to compete in games and challenges for the control of territory, which quickly escalated to open hostility and escalating violence. In stage three, conflict resolution, several urgent matters were orchestrated which required the cooperation of both groups to arrive at a solution, culminating in total reconciliation. See also: superordinate goal.