Extreme segregation can emerge without anyone desiring segregation

Evidence

Schelling (1971) examined how segregation between social groups can arise through the actions of individual agents, even when no agent specifically desires segregation. Schelling’s model assumed that each agent used a single, simple rule: do not be in the minority in your neighborhood. To implement the model, agents moved to random empty spaces if the proportion of “in-group” agents surrounding their current space fell below a certain threshold, such as 50%. The rule was applied until all agents stopped moving, settling into their spaces. The final result, which occurred under a wide range of moving thresholds, was almost complete segregation among the agents, with clear group boundaries. This model was important because it offered the counterintuitive conclusion that extreme segregation may inevitably result from the extended interactions and choices of individuals who do not necessarily desire extreme segregation. — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 824

Categorization

• XREF: Echoes the ‘Grafting & Growth’ article’s interest in emergent system properties; also connects to Milgrom’s discussion of emergent trade institutions from individual rational choices. — connects to: Peace settlements can increase rather than reduce physical segregation barriers — Nadim N. Rouhana and Nadera Shalhoub-Kevorkian, When Politics Are Sacralized:…, 2285; Segregation was deliberately engineered through planning policy, not emergent preference. — Matthew D. Lassiter, The Suburban Origins of “Color-Blind”…, 21; Segregated space silently perpetuates stratification even with no active racists (+1 more)
• SEED: An essay angle: how local, innocuous preference rules (tolerate minorities above a threshold) compound into stark global outcomes across housing, social networks, and organizational homophily.