Watch a City Segregate Itself

Every resident of this city is genuinely happy to be outnumbered on their own street. Nobody wants segregation. Now watch the map tear itself into solid blocks anyway — live, in twelve ticks. You've seen the sorted map before: the neighbourhoods on one side of the tracks, the cafeteria at 12:05, the group chat that quietly became an echo chamber. The easy explanation is that people must want it. This simulation is the counterexample — 690 residents, one shockingly mild preference ("I'd rather not be almost the only one"), no mayor, no zoning, no plan. The city un-mixes itself, then freezes. Forever. And there's a cliff hiding in the system: a single notch on the preference dial separates a city that stays mixed from a city that locks into blocks — 25% stays blurry, 26% tips. The honest part: none of this proves why your city looks the way it does. Real cities had redlining, lending discrimination, zoning, economics — deliberate forces this model doesn't contain. What the model shows is quieter and scarier: erase all of that, keep nothing but one mild preference, and the map can still un-mix on its own. Based on Thomas Schelling's 1971 model "Dynamic Models of Segregation." Everything on screen replays one committed simulation run — the numbers are measured, not hand-animated. 🎬 Animated with motion graphics — the diagram is the explanation. ⏱️ Chapters 00:00 The map you've already seen 00:33 One rule, no mayor, no plan 01:25 The reveal: one third is enough 01:55 Watch the city un-mix, tick by tick 02:34 The last mover — and the freeze 03:21 Why one reasonable move snowballs 03:59 The dial: 25% vs 26% — the cliff 05:25 What this proves — and what it doesn't 06:21 Your map, your number 💬 What's your number? What share of "people like me" would you quietly want before you left the table, the chat, the street? Be honest — tell me in the comments. 🔔 Subscribe for more social systems and simulations, animated. #SchellingModel #Emergence #Simulation