Gaertner, L., Sedikides, C., & Graetz, K. (1999). In Search of Self-Definition: Motivational Primacy of the Individual Self, Motivational Primacy of the Collective Self, or Contextual Primacy? Journal of Personality and Social Psychology, 76, 5-18.

Four investigations examined the dynamics between the individual self (self-representation independent of group membership) and the collective self (self-representation derived from group membership). Relative to participants whose collective self was threatened, participants whose individual self was threatened (a) considered the threat more severe (b) experienced a more negative mood, (c) reported more anger, and (d) derogated to a greater extent the source of threat. In addition, a self-description task indicated that participants generate more aspects of their individual than collective self. These effects occurred even when confounding variables (i.e., accessibility of the selves, group identification, individualism and collectivism, importance of threat domain) were controlled. The individual self is motivationally primary.