1. Faculty of Management, Economics and Social Sciences, The Institute of Sociology and Social Psychology, University of Cologne, Cologne, Germany
2. Department of Sociology, and URPP Social Networks, University of Zurich, Zürich, Switzerland
3. Department of Psychology, University of Zurich, Zürich, Switzerland
4. Faculty of Social Sciences, Department of Sociology and Anthropology, Tel Aviv University, Tel Aviv, Israel
5. Faculty of Social Sciences, Department of Sociology, University of Haifa, Haifa, Israel
6. Institute of Political Science, University of Giessen, Giessen, Germany