An Organic Unruliness

Human seems to have a skill of instinct - distinguish a slum in his first glance from other communities. When we see a photo of a slum, no matter from any place around this planet, we can easily tell if this is a slum or not. So what is the similarity of slums? I'd like to call it an organic unruliness. 

Occupants living in a slum are, obviously, people who have not enough skills, wealth or resources. However, although they have the semblable poverties, they still lead very different lives. Some occupants lived with kids need more spaces and gather together, while single ones can focus on other things with smaller accommodations. Some occupants find metal decks from a scrap recycling plant to build his own partitions while some can only use industry canvases. No architects would design their life and no rules exist for them to follow. A slum forms and evolves spontaneously and organically. When this slum grows to a certain scale, with surprise, people suddenly find that a subtle but traceable formal logic emerges behind it. This is the logic of nature - bottom-up. 

Modern cities are much further from the logic of nature rather than a slum. A small group of citizens decides the pattern of the whole city. Tons of districts with different functions such as industry, commercial, residence, education etc. are organized in perfect order. Then buildings are organized in perfect order in these districts. Then programs are organized in perfect order in these buildings. After all these steps, we as citizens will lead our lives in these buildings and districts in the way that have been already set up. This is the typical "top-down" train of thought that we did to modern cities and our lives. Maybe this is the right thing that we need to learn from a slum.