Where Good Ideas Come From

by Steven Johnson

Economists have a telling phrase for the kind of sharing that happens in these densely populated environments: “information spillover.” When you share a common civic culture with thousands of other people, good ideas have a tendency to flow from mind to mind, even when their creators try to keep them secret. “Spillover” is the right word; it captures the essential liquidity of information in dense settlements. As species go, Homo sapiens had been on a fairly good run in the million years that led up to the birth of agriculture: its members had invented spoken language, art, sophisticated tools for hunting, and cooking. But until they settled in cities, they had not figured out a way to live inside a high-density liquid network.