Complexity

For the use in computer science, see Computational complexity. For other uses, see Complexity (disambiguation).

Complexity characterizes the behavior of a system or model whose components interact in multiple ways and follow local rules, leading to non-linearity, randomness, collective dynamics, hierarchy, and emergence.[1][2]

The term is generally used to characterize something with many parts where those parts interact with each other in multiple ways, culminating in a higher order of emergence greater than the sum of its parts. The study of these complex linkages at various scales is the main goal of complex systems theory.

The intuitive criterion of complexity can be formulated as follows: a system would be more complex if more parts could be distinguished, and if more connections between them existed.[3]

As of 2010, a number of approaches to characterizing complexity have been used in science; Zayed et al.[4] reflect many of these. Neil Johnson states that "even among scientists, there is no unique definition of complexity – and the scientific notion has traditionally been conveyed using particular examples..." Ultimately Johnson adopts the definition of "complexity science" as "the study of the phenomena which emerge from a collection of interacting objects".[5]

  1. ^ Johnson, Steven (2001). Emergence: The Connected Lives of Ants, Brains, Cities. New York: Scribner. p. 19. ISBN 978-3411040742.
  2. ^ "What is complex systems science? | Santa Fe Institute". www.santafe.edu. Archived from the original on 2022-04-14. Retrieved 2022-04-17.
  3. ^ Heylighen, Francis (1999). The Growth of Structural and Functional Complexity during Evolution, in; F. Heylighen, J. Bollen & A. Riegler (Eds.) The Evolution of Complexity. (Kluwer Academic, Dordrecht): 17–44.
  4. ^ J. M. Zayed, N. Nouvel, U. Rauwald, O. A. Scherman. Chemical Complexity – supramolecular self-assembly of synthetic and biological building blocks in water. Chemical Society Reviews, 2010, 39, 2806–2816 http://pubs.rsc.org/en/Content/ArticleLanding/2010/CS/b922348g
  5. ^ Johnson, Neil F. (2009). "Chapter 1: Two's company, three is complexity" (PDF). Simply complexity: A clear guide to complexity theory. Oneworld Publications. p. 3. ISBN 978-1780740492. Archived from the original (PDF) on 2015-12-11. Retrieved 2013-06-29.