教育格差の解明：政治的アイデンティティにおける高等教育の重要性の高まり

Higher education is widely believed to have a liberalizing effect on students, yet empirical findings are mixed. In two studies (total N = 483,885), we investigated the "diploma divide" in the United States. In the past half-century, we found that adults with more education have consistently held more left-leaning views on social but not economic issues. Before the 2010s, however, there were no meaningful, educational differences in the degree to which people identified as liberal versus conservative. In the years since, college graduates have increasingly identified as liberal, while those with some or no college education remained steady. Moreover, in the mid-1990s, students did not come to identify as more left-leaning during their time in higher education. However, they have increasingly done so in the years since. Such within-person changes differ across fields of study, demographics, and other individual characteristics, but are minimally related to the kinds of institutions that students attend. Overall, these findings reveal a striking change in the relationship between higher education and political identity. They also undermine sweeping claims about liberalizing effects of education, calling instead for fine-grained theories about how, when, and for whom attending higher education affects which aspects of ideology. (PsycInfo Database Record (c) 2026 APA, all rights reserved).