Many people believe that a university education leads to the liberalization of students' worldviews. The author aimed to investigate whether such differences occur across disciplines and whether they are due to self-selection or socialization within disciplines. The author conducted 3 correlational studies of university students (N = 223, N = 531) and alumni (N = 143). The results clearly supported the self-selection hypothesis and suggested that students from all disciplines generally endorse liberal or left-wing attitudes. These findings have theoretical implications for the study of belief system development (primarily the impressionable years hypothesis), and they contribute to a greater understanding of how a university education affects the sociopolitical orientations of students.