up:: [[70 Evolutionary Potential/The Vault/Complexity|Complexity]] > [!info] Complex Adaptive Systems (CAS) Def. > Complex Adaptive Systems (CAS) is a framework for studying, explaining, and understanding systems of agents that collectively combine to form emergent, global level properties e.g., ants, bees, brain cells, traffic, groups of people (companies, towns, cities etc.). They have a significant number of self-similar agents that: > - Utilise one or more levels of feedback > - Exhibit emergent properties and self-organisation > - Produce non-linear dynamic behaviour ![[Complex Adaptive System (CAS) Model.png]] Image sourced from [ReasechGate](https://www.researchgate.net/publication/237279219_Integrating_Complexity_Theory_Knowledge_Management_and_Organizational_Learning) ## CAS produce complex emergent behaviour A key feature of CAS is that they produce complex emergent behaviour via interdependent feedbacks throughout the system. As the feedbacks move the system away from equilibrium it undergoes a sequence of catastrophic phase changes, from [[Point Attractor]] to [[Limit Cycle Attractor]] and then to complexity. New [[Context-sensitive Constraints]] appear with each transition, as do new properties. These phase changes are paid for by a burst of overall [[Entropy]] production. Often, these complex behaviours are assumed to be caused by strong top-down organisation (known as [[Hierarchical Bias]]) and/or a subset of complicated agents (known as [[Complexity Bias]]). Where in reality, complex behaviours can emerge from quite simple rules ([[Context-sensitive Constraints]]). ## CAS achieve cost effective resilience Another key feature of CAS is that they're resilient in the face of external forces--to a point (at certain thresholds CAS begin a rapid transition to a, yet know, new state). [[Fitness Functions]] inherent in nature ([[Evolution|survival of the fittest]]) push systems towards efficient use of resources e.g., thousands of autonomous, simple ants that don't require constant instruction are more efficient, and more resilient, than one central, complicated, irreplaceable, and over-worked queen. > [!important] > Embracing complexity is more cost effective and resilient than more traditional approaches to organisation. ## CAS are present at all scales of inquiry Complex Adaptive Systems are present at all scales of inquiry e.g., from the movements of economies and markets to individual knowledge acquisition, or from large-scale social interaction down to small scale cellular behaviour. ###### Sources: [[The Fundamentals of Complex Adaptive Systems by Carmicheal and Hadzikadic]] [[Dynamics in Action by Alicia Juarrero]] ###### Related: left:: [[Non-linear Dynamical Systems]], [[Complexity Science]], [[The Principle of Least Effort]]