I am an Assistant Professor of Sociology at the University of California, Los Angeles. My research examines how social identities and ideologies shape and are reshaped by violence, especially in contexts of war and genocide. I study how people classify themselves and others, how these classifications change under extreme pressure, and how they influence decisions to participate in, resist, or abstain from violence. By using qualitative, historical, and experimental methods to craft falsifiable theories of violence, my research spans culture, politics, morality, identity, and conflict.

My book, Sacred Betrayal: How the French Catholic Church Broke Its Pledge to Protect Jews during the Holocaust, is forthcoming with Harvard University Press. I am also co-author (with Shai Dromi and Steve Hitlin) of the second Handbook of the Sociology of Morality (Springer). My research has appeared in American Sociological Review, Sociological Theory, European Journal of Sociology, Social Science History, and other journals, as well as in major public outlets including The New York Times, The Washington Post, and the Los Angeles Times.

I serve on the Steering Committee of the University of California Institute on Global Conflict and Cooperation and am affiliated with the UCLA Initiative to Study Hate and the UCLA Bedari Kindness Institute. Before joining UCLA, I worked with USAID, the United Nations CTED, the Montreal Institute for Genocide Studies, and Facing History & Ourselves.