Why mild preferences can build a segregated town: Schelling's chequerboard

30seconds
Nobody in this town wants it split into blue and orange districts. Each household only asks that a few of its neighbours look like it. Yet run the rule and the town sorts itself into neat colour blocks.
This is Schelling's segregation model, from the economist Thomas Schelling, who published it in 1971. Drag the tolerance slider, press Run and watch small preferences add up to a pattern nobody ordered.
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