A simple example

One of the most basic ideas of social atomics is that patterns are often more important than people. Here's a really simple example. Think of a crowded sidewalk with people moving in both directions -- some to the left, say, and some to the right. If you've been out shopping over Christmas, you've probably been in a situation like this. Each person walks according to their own independent aims, yet what you typically find emerging in such situations is a natural segregation of the human traffic into well-defined lanes moving in either direction. You can see a nice simulation of the process here on the website of the German physicist Dirk Helbing. The blue arrows represent people moving to the right, and the red people moving left. In the simulation, the walkers start out mingling at random, but over time lanes naturally emerge.

You can ponder the depths of individual human complexity all you like and never explain this -- because these lanes emerge all on their own, without anyone intending to make them. The explanation has to do with pattern and what creates it, not the nuances of individual psychology. Here's the basic story. When people walk they go where they want to go, except for one thing -- they generally try not to run into others. This is an obvious fact, yet it has not-so-obvious consequences. When two people meet, one or both need to shift sideways a little (either up or down in this case) to get past one another. This is enough to generate the organization. That's because when people shift sideways to avoid a collision, they'll continue shifting so long as they continue to encounter people heading in the opposite direction. They'll only stop shifting and go forward again when they find other people heading in their own direction. As a consequence, people tend to get bounced sideways until they find and join a lane moving in their direction. Any lane that forms, even by accident, will tend to persist and grow.

This is a simple, indeed trivial example, involving only our very rudimentary behaviour when walking. The really interesting thing is to wonder whether similar kinds of patterns might not influence our lives in other areas -- in the words we use, the thoughts we think and opinions we hold. There well may be patterns and social streams that carry us along much as these lanes to pedestrians. The point of social physics is to try to identify such streams, learn where they come from and what controls their formation, and to see how they influence our lives.