Intergroup research has focused primarily, if not solely, on how an intergroup comparative context primes social categorization. The current research examines how individual differences, in terms of distinct forms of social self (the relational versus collective self), differentially drive social categorization and zero-sum resource allocation across groups nested within a superordinate group. Results show that the relational self exhibited more ingroup-biased allocations than the collective self: superordinate categorization mediated this relationship. Moreover, the relational self showed more ingroup-biased allocations under the condition of intergroup competition than cooperation: whereas the collective self showed equally unbiased allocations under the conditions of intergroup competition and cooperation. Our research suggests that competition worsens nested group relations for the relational self, but not for the collective self. (C) 2012 Elsevier Inc. All rights reserved.