In this research, we explore the effect of college instructors' use of formal versus casual titles on student perceptions as a function of the instructors' academic ranks. We conducted two studies: the first surveying students to study their expectations and preferences of formality and rank, and the second using experimental manipulations of title formality and instructor rank to examine the effects on student perceptions of instructors and their classes. Our data indicate that a full professor is perceived more favourably than a graduate assistant when using a casual title (their first name). Conversely, the pattern goes the opposite when they use a formal title. These insights were assessed through course favourability and enrolment intention and were rooted in two fundamental individual traits: competence and approachableness. In addition, the effects are less pronounced for students with previous exposure to the course content, suggesting course experience as a moderator. This study offers guidance on student-instructor interactions and provides insights for educators in presenting themselves through different titles.