Author's Note:  Sonja Utz received her Ph.D. in Psychology from the Catholic University of Eichstadt (Germany) in 1999, where her thesis dealt with "Social Identification with Virtual Communities: Causes and Consequences."   She is currently a member of the faculty in the Department of Economic, Organizational, and Social Psychology at Chemnitz University of Technology; after April, 2000, she will be affiliated with the Free University in Amsterdam.  Her esearch interests include computer-mediated communication, virtual communities, social identity, cooperation and competition.  Dr. Utz's homepage is http://www.tu-chemnitz.de/phil/psych/professuren/sozpsy/Mitarbeiter/Utz/utz.html.

The author wishes to thank Kai Sassenberg and two anonymous reviewers for insightful and critical comments on earlier drafts of the paper; Ruth Loemke, for language and stylistic assistance; and the 103 MUDders who participated in this study.