A sample of 108 elementary student teachers was administered the Pupil Control Ideology Form (PCI Form) before and after student teaching. The student teachers' perceptions of their cooperating teachers' pupil control ideology were measured using a modification of the same form. "Socialization pressure," the difference between the student's pretest PCI Form score and the perceived pupil control ideology of the cooperating teacher, was also used as a variable. Student teachers as a group became significantly more custodial (shown by increased PCI Form scores) during student teaching. Comparison of students showing no increase in PCI Form scores and an equal number showing the largest increase, showed the two groups to differ significantly on mean perceived PCI scores and on mean socialization pressure. Examination of the differences in mean change in PCI Form scores of students in situations of low, medium, and high socialization pressure showed significant differences between low and high groups and low and medium groups. (EB)