Consider this story of two men. One man consistently comes home from work at precisely 5:45 every day. Another man arrives home every day anywhere between 5:30 and 6:30. One day, the first man is not home by 6:00. He's only 15 minutes late, but his family is not used to him not being home on time, so they worry that something bad has happened. One day, the other man is not not home by 7:00. Despite his being 30 minutes late, his family is not too concerned because they are used to his arrival time being highly variable.

In his book Antifragile, Nassim Taleb uses simple narratives like this one to illustrate that the more we encounter chaos, the more we tolerate chaos. The less we encounter chaos, the less we tolerate chaos. We see our tolerance for chaos reflected in our built environment.

My wife and I have been homeowners twice, and both times we have either refinished or installed wood floors. I have noticed that my behavior changes when the floors are nice. When the floors were scuffed up, with dings, dents and patches where the polyurethane had worn down, we were not that careful about sliding furniture across the floor. But, now with perfect floors, I want them to stay perfect as long as possible, so we tip-toe around in socks and every little dent and scratch bothers me. (If you've ever had wood floors, you know that it is impossible to keep them in perfect shape. Especially after the movers slide your furniture around!)

It does not seem hard to imagine that the same phenomenon affects the way our communities are built. The more uniform we become, the less variance we can tolerate. For example, imagine a town where everyone lives in nearly identical houses, earns nearly identical incomes, shares a nearly identical cultural background, and maintains nearly identical front yards. That’s not too far off from some real places that exist, places where we may develop such a low tolerance of chaos that even having the wrong blinds can upset our neighbors.

I could not help but think of the planners and legislators that get frustrated any time people do not act according to what they prescribe. Whether it is something simple such as people wearing a desire path through the grass instead of taking the provided path the long way round, painting in their own bike lane, or getting upset because people are finding a creative way to provide affordable housing that the law did not intend. When we attempt to micromanage every small detail, that which does not act the way we want will annoy us.

The wrong kind of city building is that which obsesses over the iron grid, with a perfect plat that divides the land into perfectly identical lots, with perfectly straight build-to lines, and perfectly matching height limits. If we aim for perfection, small imperfections will bother us—the one building that is set back too far, or is too short, or too tall, or is on a non-conforming lot, or the one street that is narrower than the rest.

I was recently in Europe, and I am fascinated with what we can learn from the pre-modern environment that still exists in much of Europe. In the medieval cores of traditional cities, rarely was anything perfect. The streets were not perfectly straight, intersections were not perfect right angled, the lots were not perfectly uniform, and the roofs were not perfectly aligned.