It has been found that student teacher attitudes toward pupil control change from relatively humanistic to relatively custodial during their student teaching experience. The objective of this investigation was to evaluate the use of T-groups as an intervention for modifying teacher attitudes toward classroom control. An underlying assumption of the T-group method is that understanding and developing skills in participation can best be learned immediately through the process of group continuum to humanism on the other end. The pupil control ideology of student teachers is influenced by the role of the teacher in the schools in which they do their student teaching. A prepost test with treatment and control design was adminstered to 48 student teachers to elicit their pupil control ideology. During the period between the two tests, the students participated in four different T-group sessions. The results of the study indicate that ongoing T-group training can work as an effective intervention in the socialization of student teachers' pupil control ideology. The results further suggest that encounter groups can be a significant force when direct application of new attitudes can be made concurrent with T-group participation. Implications for using T-groups as a means of developing more humanistic climates in secondary schools is suggested by this study. (SK)