For each of the following examples, describe whether it can be best understood within the reductionist paradigm or the complex systems paradigm, and explain why.
A bottle of water: reductionist paradigm. There are too many particles for us to track them all, but the water’s properties, such as temperature and pressure, can be understood with statistics.
A single living cell in an organism: complex systems paradigm. There are many interrelated processes going on within a cell. It exhibits emergent patterns, but the components do not all behave like a perfectly predictable mechanism.
A toaster: reductionist paradigm. A toaster has relatively few components and they are rigidly configured such that pushing the lever down should reliably trigger a series of events that switches it on to toast the bread.
A city’s inhabitants form a complex social system. We can generally predict with high levels of confidence and reliability how busy the roads and public transport systems will be at certain times of day. How does this kind of predictability differ from what we can predict about a simple system?
Certain patterns of regularity often emerge in complex systems, so we may be able to predict certain aspects of their behaviors, particularly if they are familiar systems that we have a lot of historical data on. However, we cannot usually predict the behaviors of complex systems in more detail, such as which specific cars will be travelling along which roads at a precise time. This is in contrast with simple, mechanistic systems, for which we can usually predict at a higher level of detail what each component will do at a given time in response to an input. It can also be more difficult to predict the long-run trajectory of complex systems, for example what the transport system and roads will look like in 100 years, because complex systems can evolve more freely into a wider range of states. Mechanistic systems on the other hand tend not to evolve independently in this way.
For each of the following phenomena, identify which hallmark(s) of complexity it demonstrates and explain your answer.
1. Emergence
2. Adaptive behavior
3. Distributed functionality
4. Scalable structure and power laws
5. Feedback loops and nonlinearity, self-organized criticality