Socially distanced layout of the world’s oldest cities helped early civilization evade diseases

Excavations at Çatalhöyük show how closely people lived before the settlement collapsed. Mark Nesbitt/Wikimedia Commons, CC BY

In my research focused on early farmers of Europe, I have often wondered about a curious pattern through time: Farmers lived in large dense villages, then dispersed for centuries, then later formed cities again, only to abandon those as well. Why?

Archaeologists often explain what we call urban collapse in terms of climate change, overpopulation, social pressures or some combination of these. Each likely has been true at different points in time.