1. Department of Social and Developmental Psychology Sapienza University of Rome Rome Italy
2. Department of Psychology The Hebrew University of Jerusalem Jerusalem Israel
3. Institute of Sociology and Social Psychology University of Cologne Köln Germany
4. Department of Sociology, and URPP Social Networks University of Zurich Zürich Switzerland
5. Institute of Psychology Cardinal Stefan Wyszynski University Warsaw Poland
6. Department of Psychology Sapienza University of Rome Rome Italy