Lilliana Mason is an SNF Agora Institute Professor of Political Science at Johns Hopkins University. She is author of Uncivil Agreement: How Politics Became Our Identity (2018) and co-author, with Nathan P. Kalmoe, of Radical American Partisanship: Mapping Violent Hostility, Its Causes, and the Consequences for Democracy (2022). She received her PhD in political psychology from Stony Brook University and her BA in politics from Princeton University. Her research on partisan identity, social sorting, American social polarization, and American political violence has been published in leading political science journals, and featured in media outlets including the New York Times, the Washington Post, CNN, and National Public Radio. She is a member of the 2024 class of Andrew Carnegie Fellows.