Teachers of psychology tend to agree that learning about diversity is an important goal for undergraduate psychology courses. There is significantly less agreement about what aspects of diversity psychology students should understand. The current research proposes and investigates two potentially distinct ways students might understand diversity: more scientific understandings of topical knowledge related to nature and nurture and more humanistic understandings related to multicultural awareness and sensitivity. Drawing on standardized surveys and open-ended responses to diversity questions from the beginning and end of introductory psychology courses, results indicate that students' topical knowledge of diversity is not strongly associated with multicultural sensitivity. These results emphasize the importance of clarifying the meanings of addressing diversity as a course goal and are discussed in relation to the multiple challenges of teaching about diversity in psychology courses.