Excerpt from Strong Towns: A Bottom Up Revolution to Rebuild American Prosperity

Chapter 1: Human Habitat

I had the opportunity to spend time in Italy during my mid-20s. Walking amid the ruins of Pompeii, I noted a little shop that had served as the fast food restaurant of its day. It was located on one of the direct paths from the core of the city to the edge, although it was closer to the outskirts than the center of the action.

The building was small: just two rooms. The room furthest from the street was the living quarters, closed at the back but with an opening to the front. The front room along the street was where the food was kept warm and dispensed out of pots placed under a countertop. The countertop ran along the sidewalk for ease of service.

As an engineer who had worked on site layout and project development for a handful of fast food restaurants, my initial reaction was: how quaint. Look at how these simple people lived. What a hard and miserable life. Thank goodness we are so much more intelligent and sophisticated today. Thank goodness we have risen above this.

In subsequent years, I would grow to realize how ignorant I had been.

With just two rooms, the family member who ran the fast food operation in front could also keep an eye on small kids in back, taking a break from sales when times were slow and being more attentive when they were not. Thus, half the household’s parents could both create an income stream and care for young family members simultaneously.

This freed up the other half of the household, along with any extended family that lived under the roof, to get a job elsewhere, likely outside of the city doing some form of manual labor. Matthew 20, in the New Testament, relays the Parable of the Workers, describing how people would line up in the marketplace to be selected for manual labor. This was a common arrangement of the day, with those selected earning a day’s wages.

What this family had created was income diversity. If no labor was to be had that day, hopefully the restaurant would provide some fallback income. If the restaurant had a slow day, ideally it was because there were wages to be had laboring in vineyards. If both had a successful day, it allowed some savings to accrue for those times when both sources of income dried up.

A stretch of good fortune for both income streams would cause savings to grow into a nest egg, some real wealth that could be used to improve the family’s situation. Maybe they used that wealth to expand the restaurant. Or to hire help, perhaps purchasing a slave culled from the ranks of a defeated enemy, which was common practice. Again, I’m not describing a utopia; I’m describing a complex system that imperfectly harmonizes many competing priorities simultaneously over time.

What is important is that the strategies emerging in such systems are anti-fragile. They limit the risk of catastrophe while maintaining the capacity for improvement, particularly during stress events. These are the strategies that survive the test of time, and when it comes to the Pompeii fast food restaurant, I’m just getting started.

The building was located near the edge of town. The land was likely acquired for free or at a very low price. Prime real estate near the center of town would have been much more expensive, but on the edge, someone could start with relatively nothing. Yet, if the community grew and prospered, the edge would expand outward. The shop owner would then find themselves with an investment now strategically located closer to the center than a more valuable situation.

The little shop owner thus shared a common fate with other property owners in the city. It was not a zero-sum game, where one benefits only at the expense of others. I’m not suggesting they all lived in harmony, but they had a lot of selfish incentives for altruism.

This makes the common walls of the buildings more understandable. The Pompeii fast-food structure shared a wall with its neighbor on each side. We can appreciate the lawyers and building inspectors involved with something like this today, but historically, shared walls were the norm. Common walls meant shared cost, an advantage when you were short on resources. It also meant that heat would dissipate more slowly in cold seasons, reducing fuel consumption.

With buildings sharing common walls and having their sole entrance face the street, the place was made more secure for everyone. Someone wanting to enter a home for nefarious reasons would be subject to the random watchful gaze of neighbors, both during an approach and upon exit. Even in cities where there was a paid security force, this design was a way to provide a decent amount of security at a marginal cost.

To the extent that human and animal waste in the streets allowed, the street itself was a place for people to gather, including neighborhood children. Shared parenting—I’ll watch your kid and you watch mine—took the strain off raising kids who were too old to be kept in the home, but not yet old enough to work.

The building itself was very simple, just a two-room box. It’s easy to see that if things didn’t work out with the restaurant, the building could be adapted to a new use. Or, if things worked out really well, the neighboring building could be acquired and the two merged together. If sometime in the future that arrangement no longer worked, the buildings could be easily subdivided again. The inherent flexibility meant that people didn’t need to be able to project what would happen in the future to act today; they just built structures that could be adapted to harmonize changing priorities.

The collection of buildings on either side of the fast food restaurant were built in a line. They faced a mirrored set of buildings on the opposite side of the street, also in a line. These opposite rows of buildings were spaced at ratios comfortable to human beings. They were not so close as to feel constrained, but they were not so far that they failed to create an edge.

Edges are very important for humans. In our habitats, we are drawn to edges. This is a phenomenon observed by Jane Jacobs in her book The Death and Life of Great American Cities, then elaborated on by Christopher Alexander in A Pattern Language. In public spaces, Jacobs notes that people “stay to the sides,” while Alexander states that people “naturally gravitate towards the edge.” This street in Pompeii provided that opportunity.

Biologists call this wall-hugging trait thigmotaxis. Think of a mouse scurrying along the edge of a wall, instinctively fearful of journeying into the center of the room. Humans have that same propensity. Darwin called evolution a “conservative process” in that it conserves winning strategies and builds on them. At some point in the very distant past, thigmotaxis was a winning strategy. The alignment of the buildings along the street in Pompeii comforted that primal urge.

In the book Cognitive Architecture, Ann Sussman and Justin B. Hollander explore how humans respond to the habitats they have built for themselves. They explore thigmotaxis, but they also dig into a phenomenon called pareidolia, the propensity for humans to find faces in objects. When people see Elvis or the Virgin Mary in a piece of burnt toast, they are experiencing pareidolia.

Faces trigger a strong emotional response in humans. Sussman and Hollander quote the Danish architect Jan Gehl in suggesting, “Man is man’s greatest joy,” that people delight in seeing other people. As written in Cognitive Architecture: