Tobias H. Stark, PhD, is assistant professor at the Department of Interdisciplinary Social Science at Utrecht University, and a researcher at the European Research Centre on Migration and Ethnic Relations (ERCOMER). His research focuses on the intersection of racial/ethnic prejudice and intergroup relations in social networks. He studies how prejudices develop within social networks, how prejudices spread through existing social networks, and how prejudices might affect changes in the structure of social networks. Stark developed new methods to collect social network data, and is involved in the development of intervention programs for schools that use insights from his research on social networks to reduce prejudice and improve interethnic relations.