Research has shown that children's differentiation of gender-appropriate behavior is not directly affected by their teacher's gender. However, the teacher's behavior in relation to the material being taught may convey the sex-appropriateness or -inappropriateness to the child. To examine the effects of student gender and sexual stereotype of the instructional material on the nonverbal behaviors of the teacher, 10 teachers from upper elementary grades taught 20 first-grade and 20 second-grade students. Each teacher taught individual lessons in which items were stereotyped as either traditionally feminine or traditionally masculine to 2 girls and 2 boys. Lessons were videotaped and judged for warmth, enthusiasm, and reinforcement. Results showed that incongruence between the sexual stereotype of the items and the gender of the student affected the nonverbal behavior of the teacher. Teachers were judged to be friendlier toward female students while working on material that was culturally inappropriate for females and to be friendlier toward male students on material that was culturally more congenial to the student's gender. The findings suggest that differential teaching behaviors may contribute to the sex-role socialization of students. (Author/NRB)