Vertical comparisons create identity antagonism while horizontal ones allow dual identity

Evidence

Engaging a dual identity is what distinguishes the two explanations for superordinate inclusiveness. With vertical comparisons, one of the social categories—the subgroup or the superordinate—will necessarily be more optimally distinct relative to the other, thereby reinforcing an identity antagonism. By contrast, if a horizontal comparison determines the superordinate category’s inclusiveness, a dual identity can be established, where both categories could be optimally distinct and thereby engage a dual identity. — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 696

Categorization

• QUESTION: How does this vertical-versus-horizontal comparison axis map onto real intergroup hierarchies (e.g., majority vs. minority, settler vs. indigenous)? The mechanism seems ripe for testing against asymmetric status relations.
• XREF: Connects to the Allport ingroup/outgroup mechanism account and to optimal distinctiveness theory; also parallels social identity theory’s treatment of how equal-status contact reduces prejudice.
• corroborated: 3 independent passages support this claim — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 696