Why do reforms that promise to fix a school system or a hospital so often leave things much as they were? Systems thinking answers questions like this by looking less at the separate parts of a situation and more at how they are connected, and at what the connections make happen over time.
Elements, connections and purpose
The environmental scientist Donella Meadows put it plainly: a system is a set of elements connected so that together they produce their own pattern of behavior over time. A system has three ingredients. The elements are the visible things: the players, the ball and the field in a game of football; the students, teachers and buildings in a school. The interconnections are the relationships that link the elements: rules, physical flows, and signals of information. The purpose, or function, is what the whole arrangement tends to achieve.
Meadows pointed out that changing the elements usually changes a system least, while changing its connections or its purpose changes it most. A football club can replace every player over ten years and still be recognizably the same club. Change the rules so that players may carry the ball in their hands, and you have a different game altogether.
Purpose is shown by behavior
The purpose of a system is not always the one written in its mission statement. A system's real purpose is best read from what it actually does over time, not from what it says it aims to do. A city that declares clean air its top priority but never enforces its pollution rules is showing its working priorities through its behavior. The British management thinker Stafford Beer turned this into a short slogan, which amounts to saying that the purpose of a system is simply what it does.
This is not cynicism. Often no one chose the outcome: each part pursues a sensible local goal, and the whole produces a result that none of them wanted.
Emergence
Emergence is behavior of a whole that none of its parts shows on its own. A single water molecule is not wet. A single neuron does not think. A single buyer does not set the price of bread, yet a market full of buyers and sellers produces prices that no one person decided. Emergence is the reason a search for the one author of a pattern can mislead. Sometimes there is an author. Often there is only a structure.
Events, patterns and structures
A common teaching device pictures a situation as an iceberg. At the visible tip are events: what happened today. Directly below the events lie patterns, the trends that show up when events are tracked over time. Deeper still are structures: the rules, incentives, physical layouts and information flows that keep producing the patterns. At the bottom are mental models, the beliefs and assumptions that hold the structures in place. The iceberg model holds that lasting change usually comes from addressing structures and mental models rather than from reacting to single events.
An old idea with new tools
The insight is old. In 1911 the naturalist John Muir wrote, "When we try to pick out anything by itself, we find it hitched to everything else in the Universe." In the twentieth century the idea gained tools. After the rise of cybernetics in the 1940s, system dynamics was founded by the engineer Jay Forrester at MIT in the 1950s, using computer models of stocks, flows and feedback to study factories, cities and eventually the whole world economy.
For citizens the payoff is practical. Many public arguments are blame stories in which someone did something bad. Sometimes that story is exactly right, and later levels insist that people remain responsible for what they do. But when the same bad outcome keeps returning no matter who is in charge, the cause probably lies in the system's structure, and replacing the people alone will not fix it.
Worked example: the jam with no cause
In 2008 a team of Japanese researchers led by Yuki Sugiyama placed 22 cars on a circular track about 230 meters around and asked the drivers to cruise at a steady 30 kilometers an hour. Within minutes a stop-and-go wave appeared and rolled backward around the ring, even though no one had braked hard or done anything wrong.
Apply the ideas. The elements are cars and drivers. The interconnections are simple: each driver watches the car ahead and reacts after a short delay. The purpose of each driver is to keep moving safely. The jam is emergent: one driver eases off slightly, the driver behind brakes a little more to be safe, the next a little more again, and the small wobble grows into a wave. On the iceberg, the jam is the event; jams that form whenever traffic passes a certain density are the pattern; spacing between cars and human reaction delays are the structure; and the belief that someone up ahead must have caused it is the mental model.
Lecturing drivers will not help much, because no one was driving badly. Changing the structure can: more even spacing, variable speed limits that slow traffic before it bunches, and, some research suggests, adaptive cruise control. The cause was in the connections, so the cure is too.