They study was conducted at a Southwestern minimum security institution. Twenty-five inmate volunteers were chosen of each behavior type (passive or aggressive). Half were randomly assigned to a group receiving nine hours of assertive training. Half were assigned to a comparison group. There were four groups in all with an assertive training focused on four common emotion-arousing situations, and it consisted of guided role playing, performance feedback, and lectures which described assertive behavior and emphasized respect for human rights as a basis for effective behavior. Comparison groups followed the same schedule. Subjects' written responses to six hypothetical emotion-arousing situations were collected before and after training and were rated for interpersonal activity and respect for others' rights. Aggressive subjects increased significantly in respect following training while passive subjects increased in activity, suggesting that both types became more assertive in responding. Aggressive subjects were found to decrease significantly in self-reported hostility and to increase in selfcontrol, while passive subjects decreased in self-reported anxiety and irritability and increased in self-control of reinforcing events. Lectures and discussions were found to be ineffective training modules in assertive training, the study indicated that assertive training can be an effective means of influencing positive behavior change in certain prison inmates. Tables, figures, approximately 100 references and six appendixes pertaining to the research are included. (Author abstract modified)