Preface (S.R. Thye et al.). Social influence networks and opinion change (N.E. Friedkin, E.C. Johnsen). Understanding Network Exchange Theory (M.J. Lovaglia). Altruism vs. self-interest in social support: computer simulations of cooperation and partner selection in social support networks (A. Flache, R. Hegselmann). The production of trust in online markets (P. Kollock). Part of life's rich tapestry: stereotyping and the politics of intergroup relations (P.J. Oakes et al.). Bounded generalized reciprocity: ingroup boasting and ingroup favoritism (Toshio Yamagishi et al.). Status orders in task discussion groups (J. Skvoretz et al.). Institutional logics and group environments: toward an open system perspective on group processes (L. Troyer, S.D. Silver).