Pub. date: 2011 | Online Pub. Date: October 04, 2011 | DOI: 10.4135/9781412994163 | Print ISBN: 9781412959636 | Online ISBN: 9781412994163| Publisher:SAGE Publications, Inc.About this encyclopedia
The science of complexity in the natural and social sciences involves the use of formalized (mathematical or computational or both) theoretical models to study systems of interacting agents where the following hold: 1. Each agent's behavior is governed by a small set of simple rules, which often depend on local information and feedback from the agent's past behavior and from other agents' behavior. 2. Characterizing and understanding the behavior of each of the agents does not directly lead to predicting or understanding the behavior of the entire system. The local rules produce emergent patterns—stable equilibria, cycles, unstable equilibria and long transitions to new equilibria, and randomness—and emergent properties such as robustness. 3. Agents' interactions are interdependent and affect others in the system; thus, removing an agent has consequences for the system beyond merely subtracting out that single agent's direct effect on other agents with which it interacts. This entry presents ...