The development and expression of sex-role identity in adolescent females and the views of teachers regarding these behaviors were investigated. Adolescent sophomore and junior females were given the Bem Sex Role Inventory during fall and spring semesters. Teacher ratings of seven characteristics were also obtained. Mean masculinity and femininity scores increased during fall and spring of the sophomore year, suggesting movement from 'undifferentiated' sex-role orientations to more definitively masculine, feminine, or androgynous. Regression analyses indicated that significant predictability of teacher ratings of instrumental behaviors, i.e., responsibility, independence, and insight, from sex-role orientations began to emerge in the latter half of the sophomore year and were strong in the fall of the junior year. (Author)