Journal of Personality and Social Psychology 1997, Vol. 72, No. 3, 617-626 Copyright 1997 by the American Psychological Association, Inc. 0022-35J4/97/S3.00 Sticking Together or Falling Apart: In-Group Identification as a Psychological Determinant of Group Commitment Versus Individual Mobility Naomi Ellemers Free University Russell Spears and Bertjan Doosje University of Amsterdam Two experiments investigated how in-group identification, manipulated with a bogus pipeline tech- nique affects group members' desire for individual mobility lo another group. In die first experiment (JV = 88), the in-group had low status, and group boundaries were either permeable or impermeable. Low identifiers perceived the group as less homogeneous, were less committed to their group, and more strongly desired individual mobility to a higher status group than did high identifiers. The structural possibility of mobility afforded by permeable group boundaries had no comparable effect. The second experiment (JV = 51) investigated whether in-group identification can produce similar effects when relative group status is unknown. Even in the absence of an identity threat, low identifiers were less likely to see the groups as homogeneous, felt less committed to their group, and more strongly desired individual mobility than did high identifiers. Results are discussed with reference to social identity and self-categorization theories. For some fans of sports teams, supporting "their" team at home and away, not only rejoicing with them after success but also sticking with them through failure and defeat, are integral features of group life. Indeed, even though there are no formal restrictions that prevent supporters from turning their backs on "their" team, or even from switching loyalties to another, more successful team, such a course of action would be unthinkable for the true fan (see e.g., Wann & Branscombe, 1990). Thus, whether fans stick with their team or not is determined not so much by the question of whether alternatives for their adulation are objectively available; rather, this is a matter of psychological commitment stemming from the importance of that particular team to the supporter's identity. In the present research we ex- amined the role such psychological factors play in people's inclination to stand by their group or to leave. More specifically, we investigated how in-group identification is related to the pursuit of individual mobility versus group loyalty and commitment. The role of in-group identification in social perception and behavior is elaborated on by social identity theory (e.g., Tajfel, 1978; Tajfel & Turner, 1979) and self-categorization theory (Turner, Hogg, Oakes, Reicher, & Wetherell, 1987). Social iden- Naomi Ellemers, Department of Social Psychology, Free University, Amsterdam; Russell Spears and Bertjan Doosje, Department of Social Psychology, University of Amsterdam, Amsterdam. The names of the authors are listed in random order: all contributed equally to this article. This research was supported by the Dutch Organi- zation for Scientific Research (N.W.O., SGW Grant 575-70-053) awarded to Russell Spears. We appreciate the help of Jolanda Jetten with Experiment 2, and we thank John Turner for his most insightful comments on a previous version of this article. Correspondence concerning this article should be addressed to Naomi Ellemers, Department of Social Psychology, Free University, Van der Boechorststraat I, 1081 BT Amsterdam, The Netherlands. Electronic mail may be sent via the Internet to n.ellemers@psy.vu.nl. tity theory was developed to explain why, under certain circum- stances, people may act in terms of group memberships (i.e., their social identity) rather than behave as distinct individuals. Departing from this general approach, social identity theory focuses on the different ways in which group members may respond to unfavorable social status, and it specifies how differ- ent beliefs about the properties of the social structure may lead people to engage in either individualist or collective coping strat- egies. Self-categorization theory elaborates in more detail the role of group identification, by specifying how salience of either one's personal or social identity may guide various social per- ceptions and behaviors. An interesting theoretical tension arises when we try to predict the responses of members of lower status groups from these two perspectives. Specifically, self- categorization theory predicts that people are more inclined to behave in terms of their group membership because their com- mon identity as group members is more salient. Social identity theory, however, suggests that people generally tend to avoid the association with a group that does not contribute to a favor- able social identity (i.e., a lower status group), especially where sociostructural conditions allow this (i.e., when group bound- aries are permeable). An important question, then, is under what circumstances members of lower status groups will feel committed to their common identity and stick together instead of opting for membership in a more attractive social group. In previous research (Doosje, Ellemers, & Spears, 1995; Spears, Doosje, & Ellemers, in press) we have demonstrated that responses to group identity threat differed depending on the person's prior level of in-group identification. In these earlier studies, we measured perceptions of intragroup homogeneity and heterogeneity in response to differences in group status (Doosje, Ellemers, & Spears, 1995) and self-stereotyping as a consequence of threats to either group status or group distinc- tiveness (Spears et al., in press). Results from these studies revealed that, compared to high identifiers, low identifiers were more likely to accentuate intragroup heterogeneity and were less 617