Investigated the verbal behavior of 152 undergraduates in 4 different classes. Trait anxiety, trait curiosity, and perceived instructor threat were measured by the State–Trait Anxiety Inventory, the State–Trait Curiosity Inventory, and the Tuckman Teacher Feedback Form. Student-initiated questions and responses to instructor questions were rated by trained observers during 8 1-hr class sessions. In general, males gave more responses than females, and Ss who perceived their instructors as threatening gave fewer responses than those who rated their instructors as nonthreatening. High curiosity stimulated student-initiated verbal behavior for both sexes, but only when the instructor was perceived as nonthreatening. For males, high anxiety inhibited the students' responses to instructor questions when the instructor was perceived as threatening, whereas females gave few responses to instructor questions regardless of their personality characteristics. (20 ref) (PsycINFO Database Record (c) 2016 APA, all rights reserved)