There are three properties that characterize all complex systems:
- Complex systems are made of relatively simple agents;
- Complex systems are self-organized, meaning they are able to organize their behavior without an internal or external “central executive”;
- Complex systems show emergent macroscopic behaviors that are hard to predict from individual components due to their nonlinear interaction. Examples of emergent properties include hierarchies, collective information processing, complex dynamics, and evolution and learning.
David Krakauer believes that a necessary condition of complex adaptive systems is that they encode or represent patterns of the world: “Everything adaptive has a model.” This enables complex adaptive systems to have goals and purpose (see Complexity is the study of teleonomic matter, after Krakauer).