Assuming that learning is an inherently social process, this research explores interpersonal variables that affect teaching. Specifically, does the interpersonal teaching style affect student impressions of the instructor? Eighty-five undergraduates viewed one of three ten-minute videos that portrayed either an authoritarian, authoritative, or neutral style. While the content remained constant, the videos differed in many ways. Students rated the authoritative style as most positive and the authoritarian as least positive. These results are consistent with socio-instructional theories of learning and imply that style is as important as substance in teaching. (Contains 2 tables and 1 note.)