Only highly inclusive superordinate categories trigger subgroup favoritism, a nonlinear effect

Evidence

Analysis revealed that greater perceived superordinate group inclusiveness was associated with greater subgroup differentiation whereby subgroup members expressed a preference for their subgroup over the other subgroup. Interestingly, additional analyses revealed that this effect appeared to be nonlinear; when the superordinate group was perceived to be fairly distinctive (i.e., when analysis of superordinate inclusiveness was conducted with scores from the bottom half of the scale), no relation between superordinate inclusiveness and subgroup differentiation was observed. Rather, the positive relation between superordinate inclusiveness and subgroup differentiation was evident when the analysis was conducted with superordinate scores from only the top half of the scale. Thus, only when the superordinate category was perceived to be highly inclusive did group members exhibit higher levels of subgroup favoritism. This evidence is consistent with the notion that too much inclusiveness leads group members to preserve and retain the distinctiveness of their subgroup. — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 679

Categorization

• QUESTION: The threshold-like nonlinearity (no effect bottom-half, strong effect top-half) suggests an inclusiveness tipping point; worth chasing how the superordinate boundary gets negotiated.
• XREF: Connects directly to the optimal distinctiveness framework thread and the cognitive mechanics of how over-inclusive categories backfire—relevant to the prior Allport-based claims about group categorization.
• SEED: Angle for an essay: how ‘too much inclusion’ (umbrella brands, big-tent movements, broad coalitions) actively manufactures internal factionalism rather than unity.
• corroborated: 4 independent passages support this claim — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 679