Contents:Section 1: Introduction. N. Ellemers, S.A. Haslam, M. Platow, D. van Knippenberg, Social identity at work: developments, debates, directions. Section 2: Motivation and performance. D. van Knippenberg, N. Ellemers, Social identity and group performance: identification as the key to collective effort. J. Wegge, S.A. Haslam, Social