Supplemental material for Cross-border friendships and collective European identity: A longitudinal study

Supplemental Material for Cross-border friendships and collective European identity: A longitudinal study by Gabriele Prati Department of Psychology, University of Bologna, Bologna, Italy Elvira Cicognani Department of Psychology, University of Bologna, Bologna, Italy Davide Mazzoni Department of Psychology, University of Milano-Bicocca, Milano, Italy in European Union Politics