For most of the six million years of human evolution, all humans and protohumans lived like somewhat glorified chimpanzees, at low population densities, scattered over the landscape as families or small bands. Only within the past 6,000 years, a small fraction of human history, did some of our ancestors come together in cities. But today more than half the world’s people live in these new settings, some of which have tens of millions of inhabitants.
Urban life involves trade-offs. We may gain big benefits in return for suffering big disadvantages. Let’s consider two of them: the trade-off between individual freedom and community interests, and the trade-off between social ties and anonymity.
To understand the issue of freedom, take first the city of Singapore, in effect one of the world’s most densely populated micro-countries. Singapore’s nearly six million people are packed into about 250 square miles—230 times the average U.S. population density. It’s an Asian financial center, a major port on one of the world’s busiest shipping straits, and a tiny piece of prime real estate wedged between two giant, powerful neighbors, Indonesia and Malaysia. Singapore was part of Malaysia until 1965, when economic and racial tensions spurred its separation. But Singapore depends on Malaysia for most of its water and much of its food, and can’t afford to make mistakes or provoke its neighbors.