Editing Stigmergy

{{short description|Social network mechanism of indirect coordination}}
[[File:Safari ants.jpg|thumb|Ant paths built from [[pheromone]] traces]]
'''Stigmergy''' ({{IPAc-en|ˈ|s|t|ɪ|ɡ|m|ər|dʒ|i}} {{respell|STIG-mər-jee}}) is a mechanism of indirect [[:wikt:coordination|coordination]], through the environment, between agents or actions.<ref name="mpra.ub.uni-muenchen.de">{{Cite journal|last1=Marsh|first1=L.|last2=Onof|first2=C.|year=2008|title=Stigmergic epistemology, stigmergic cognition|url=http://mpra.ub.uni-muenchen.de/10004/1/MPRA_paper_10004.pdf|journal=Cognitive Systems Research|volume=9|issue=1–2|pages=136–149|doi=10.1016/j.cogsys.2007.06.009|s2cid=23140721}}</ref> The principle is that the trace left in the [[natural environment|environment]] by an individual action stimulates the performance of a succeeding action by the same or different agent. Agents that respond to traces in the environment receive positive fitness benefits, reinforcing the likelihood of these behaviors becoming fixed within a population over time.<ref>{{cite journal | last = Lewis | first = Ted G. | title = Cognitive stigmergy: A study of emergence in small-group social networks | date = June 12, 2012 | doi=10.1016/j.cogsys.2012.06.002 | volume=21 | journal=Cognitive Systems Research | pages=7–21| s2cid = 40532871 }}</ref>

Stigmergy is a form of [[self-organization]]. It produces complex, seemingly intelligent structures, without need for any planning, control, or even direct communication between the agents. As such it supports efficient collaboration between extremely simple agents, who may lack memory or individual awareness of each other.<ref name="mpra.ub.uni-muenchen.de"/><ref>{{cite journal |last = Heylighen | first = Francis |  title = Stigmergy as a universal coordination mechanism I: Definition and components | date = December 1, 2015 | doi=10.1016/j.cogsys.2015.12.002 | volume=38 | journal=Cognitive Systems Research | pages=4–13| s2cid = 16431291 }}</ref>

==History==
The term "stigmergy" was introduced by French biologist [[Pierre-Paul Grassé]] in 1959 to refer to [[termite]] behavior. He defined it as: "Stimulation of workers by the performance they have achieved." It is derived from the Greek words [[wikt:στίγμα|στίγμα]] ''stigma'' "mark, sign" and [[wikt:ἔργον|ἔργον]] ''ergon'' "work, action", and captures the notion that an agent’s actions leave signs in the environment, signs that it and other agents sense and that determine and incite their subsequent actions.<ref>{{cite journal |last1=Grassé |first1=Pierre-Paul |title=La reconstruction du nid et les coordinations interindividuelles chez ''Bellicositermes natalensis'' et ''Cubitermes sp.'' la théorie de la stigmergie: Essai d'interprétation du comportement des termites constructeurs |journal=Insectes Sociaux |date=1959 |volume=6 |pages=41–80 |doi=10.1007/BF02223791}}</ref><ref>{{Cite journal|last=Bonabeau|first=Eric|year=1999|title=Editor's Introduction: Stigmergy|journal=Artificial Life|volume=5|issue=2|pages=95–96|doi=10.1162/106454699568692|s2cid=35422936|issn=1064-5462}}</ref><ref>{{cite journal | last = Theraulaz | first = Guy | title = A Brief History of Stigmergy | journal = Artificial Life | volume = 5 | issue = 2 | pages = 97–116 | date = 1999 | doi = 10.1162/106454699568700 | pmid = 10633572 | s2cid = 27679536 }}</ref>

Later on, a distinction was made between the stigmergic phenomenon, which is specific to the guidance of additional work, and the more general, non-work specific incitation, for which the term ''sematectonic'' communication was coined<ref>[[Sociobiology: The New Synthesis]], E.O. Wilson, 1975/2000, p.186</ref> by [[E. O. Wilson]], from the Greek words [[wikt:σῆμα|σῆμα]] ''sema'' "sign, token", and [[wikt:τέκτων|τέκτων]] ''tecton'' "craftsman, builder": "There is a need for a more general, somewhat less clumsy expression to denote the evocation of any form of behavior or physiological change by the evidences of work performed by other animals, including the special case of the guidance of additional work."

Stigmergy is now one of the key concepts in the field of [[swarm intelligence]].<ref name="parunak">Parunak, H. v D. (2003). [https://web.archive.org/web/20141112185202/http://abcresearch.org/papers/MSH03.pdf "Making swarming happen."] In Proc. of Conf. on Swarming and Network Enabled Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR), McLean, Virginia, USA, January 2003.</ref>

==Stigmergic behavior in non-human organisms==
Stigmergy was first observed in [[social insects]]. For example, [[ant]]s exchange information by laying down [[pheromone]]s (the trace) on their way back to the nest when they have found food. In that way, they collectively develop a [[complex network]] of trails, connecting the nest in an efficient way to various food sources. When ants come out of the nest searching for food, they are stimulated by the pheromone to follow the trail towards the food source. The network of trails functions as a shared external memory for the ant colony.<ref>{{Cite book |last1=Blum |first1=Christian |url=https://books.google.com/books?id=6Ky4bVPCXqMC&pg=PA10 |title=Swarm Intelligence: Introduction and Applications |last2=Merkle |first2=Daniel |date=2008-09-24 |publisher=Springer Science & Business Media |isbn=978-3-540-74089-6 |pages=9–12 |language=en}}</ref>

In computer science, this general method has been applied in a variety of techniques called [[ant colony optimization]], which search for solutions to complex problems by depositing "virtual pheromones" along paths that appear promising.<ref>{{Cite journal|last1=Zedadra|first1=Ouarda|last2=Jouandeau|first2=Nicolas|last3=Seridi|first3=Hamid|last4=Fortino|first4=Giancarlo|date=2017-02-02|title=Multi-Agent Foraging: state-of-the-art and research challenges|journal=Complex Adaptive Systems Modeling|volume=5|issue=1|pages=3|doi=10.1186/s40294-016-0041-8|issn=2194-3206|doi-access=free}}</ref> In the field of [[artificial neural network]]s, stigmergy can be used as a computational memory. Federico Galatolo showed that a stigmergic memory can achieve the same performances of more complex and well established neural networks architectures like [[Long short-term memory|LSTM]].<ref>{{Cite book|first1=Federico A.|last1=Galatolo|first2=Mario G.C.A.|last2=Cimino|first3=Gigliola|last3=Vaglini|title=Mining Intelligence and Knowledge Exploration |chapter=Using Stigmergy to Incorporate the Time into Artificial Neural Networks |series=Lecture Notes in Computer Science |doi=10.1007/978-3-030-05918-7_22|volume=11308|pages=248–258|year=2018|isbn=978-3-030-05917-0|bibcode=2018arXiv181110574G|arxiv=1811.10574|s2cid=53774438}}</ref><ref>{{cite book|first1=Federico A.|last1=Galatolo|first2=Mario G.C.A.|last2=Cimino|first3=Gigliola|last3=Vaglini|chapter=Using Stigmergy as a Computational Memory in the Design of Recurrent Neural Networks |title=Proceedings of the 8th International Conference on Pattern Recognition Applications and Methods|doi=10.5220/0007581508300836|isbn=978-989-758-351-3|volume=1|pages=830–836|year=2019|bibcode=2019arXiv190301341G|arxiv=1903.01341|s2cid=67855787}}</ref>

Other [[eusociality|eusocial]] creatures, such as [[termites]], use pheromones to build their complex nests by following a simple [[decentralized]] [[rule set]]. Each insect scoops up a 'mudball' or similar material from its environment, infuses the ball with pheromones, and deposits it on the ground, initially in a random spot. However, termites are attracted to their nestmates' pheromones and are therefore more likely to drop their own mudballs on top of their neighbors'. The larger the heap of mud becomes, the more attractive it is, and therefore the more mud will be added to it (positive feedback). Over time this leads to the construction of pillars, arches, tunnels and chambers.<ref>Beckers, R., Holland, O. E. and Deneubourg, J.L. [http://www.eecs.harvard.edu/~rad/courses/cs266/papers/beckers-alife94.pdf "From local actions to global tasks: Stigmergy and collective robotics."] {{webarchive|url=https://web.archive.org/web/20131104125931/http://www.eecs.harvard.edu/~rad/courses/cs266/papers/beckers-alife94.pdf |date=2013-11-04 }} Artificial life IV. 1994, p.181-189.</ref>

Stigmergy has been observed in [[bacteria]], various species of which differentiate into distinct cell types and which participate in group behaviors that are guided by sophisticated temporal and spatial control systems.<ref name=Shapiro1988>{{cite journal |last=Shapiro |first=James A. |title=Bacteria as Multicellular Organisms |journal=Scientific American |date=June 1988 |volume=258 |issue=6 |pages=82–89 |url=http://shapiro.bsd.uchicago.edu/Shapiro.1988.scientificamerican0688-82.pdf |access-date=8 September 2013 |doi=10.1038/scientificamerican0688-82 |bibcode=1988SciAm.258f..82S |archive-url=https://web.archive.org/web/20120526105956/http://shapiro.bsd.uchicago.edu/Shapiro.1988.scientificamerican0688-82.pdf |archive-date=26 May 2012 |url-status=dead }}</ref> Spectacular examples of multicellular behavior can be found among the [[myxobacteria]]. Myxobacteria travel in ''[[swarm]]s'' containing many [[Cell (biology)|cell]]s kept together by intercellular molecular [[Signal transduction|signals]]. Most myxobacteria are predatory: individuals benefit from aggregation as it allows accumulation of extracellular [[enzyme]]s which are used to digest prey microorganisms. When nutrients are scarce, myxobacterial cells aggregate into ''fruiting bodies'', within which the swarming cells transform themselves into dormant myxospores with thick cell walls.  The fruiting process is thought to benefit myxobacteria by ensuring that [[cell growth]] is resumed with a group (swarm) of myxobacteria, rather than isolated cells.  Similar life cycles have developed among the cellular [[slime mold]]s. The best known of the myxobacteria, ''[[Myxococcus xanthus]]'' and ''[[Stigmatella aurantiaca]]'', are studied in various laboratories as [[prokaryote|prokaryotic]] models of development.<ref name=Dworkin2007>{{cite journal |last=Dworkin |first=Martin |title=Lingering Puzzles about Myxobacteria |journal=Microbe |year=2007 |volume=2 |issue=1 |pages=18–23 |doi=10.1128/microbe.2.18.1|doi-access=free }}</ref>

==Analysis of human behavior==
Stigmergy studied in [[Eusociality|eusocial]] creatures and physical systems, has been proposed as a model of analyzing some [[robotics]] systems,<ref>Ranjbar-Sahraei, B., Weiss G., and Nakisaee, A. (2012). A Multi-Robot Coverage Approach based on Stigmergic Communication. In Proc. of the 10th German Conference on Multiagent System Technologies, Vol. 7598, pp. 126-138.</ref> multi-[[intelligent agent|agent]] systems,<ref>Giovanna Castellano, Mario G.C.A.Cimino, et al. A multi-agent system for enabling collaborative situation awareness via position-based stigmergy and neuro-fuzzy learning, Neurocomputing, Vol. 135 (2014) pp. 86-97</ref> communication in [[computer networks]], and [[Online community|online communities]].<ref>Mario G.C.A. Cimino, Federico Galatolo, Alessandro Lazzeri, Gigliola Vaglini. Spikiness Assessment of Term Occurrences in Microblogs: an Approach Based on Computational Stigmergy, ICPRAM 2017</ref>

On the [[Internet]] there are many collective projects where users interact only by modifying local parts of their shared virtual environment. [[Wikipedia]] is an example of this.<ref name="Rheingold">{{cite AV media|url=https://www.youtube.com/watch?v=6zWUEtmw3p4 |archive-url=https://ghostarchive.org/varchive/youtube/20211211/6zWUEtmw3p4| archive-date=2021-12-11 |url-status=live|title=Mark Elliott on stigmergy, citizen wikis, collaborative environments|date=26 August 2009|work=YouTube}}{{cbignore}}</ref><ref>{{Cite book|last=Tkacz|first=Nathaniel|url=http://dx.doi.org/10.7208/chicago/9780226192444.001.0001|title=Wikipedia and the Politics of Openness|date=2014|publisher=University of Chicago Press|isbn=978-0-226-19230-7|pages=46|doi=10.7208/chicago/9780226192444.001.0001}}</ref> The massive structure of information available in a [[wiki]],<ref name="burbeck">[http://weblog.infoworld.com/udell/gems/ju_burbeck.html Infoworld: A conversation with Steve Burbeck about multicellular computing] {{webarchive|url=https://web.archive.org/web/20081211203903/http://weblog.infoworld.com/udell/gems/ju_burbeck.html |date=2008-12-11 }}</ref> or an [[open source software]] project such as the [[FreeBSD kernel]]<ref name="burbeck" /> could be compared to a [[termite]] nest; one initial user leaves a seed of an idea (a mudball) which attracts other users who then build upon and modify this initial concept, eventually constructing an elaborate structure of connected thoughts.<ref name="heylighen">[[Francis Heylighen|Heylighen F.]] (2007). [http://pespmc1.vub.ac.be/Papers/OpenSourceStigmergy.pdf Why is Open Access Development so Successful? Stigmergic organization and the economics of information] {{Webarchive|url=https://web.archive.org/web/20081002100258/http://pespmc1.vub.ac.be/Papers/OpenSourceStigmergy.pdf |date=2008-10-02 }}, in: B. Lutterbeck, M. Baerwolff & R. A. Gehring (eds.), Open Source Jahrbuch 2007, Lehmanns Media, 2007, p. 165-180.</ref><ref>Marko A. Rodriguez|Rodriguez M.A. (2008). [http://markorodriguez.com/Research_files/collective-model.pdf A Collectively Generated Model of the World] {{webarchive|url=https://web.archive.org/web/20090106032517/http://markorodriguez.com/Research_files/collective-model.pdf |date=2009-01-06 }}, in: Collective Intelligence: Creating a Prosperous World at Peace, eds. M. Tovey, pages 261-264, EIN Press, {{ISBN|0-9715661-6-X}}, Oakton, Virginia, November 2007</ref>

In addition the concept of stigmergy has also been used to describe how cooperative work such as building design may be integrated. Designing a large contemporary building involves a large and diverse network of actors (e.g. architects, building engineers, static engineers, building services engineers). Their distributed activities may be partly integrated through practices of stigmergy.<ref>Christensen, L. R. (2007). Practices of stigmergy in architectural work. In Proceedings of the 2007 international ACM Conference on Conference on Supporting Group Work (Sanibel Island, Florida, USA, November 04–07, 2007). GROUP 2007. ACM, New York, NY, 11-20.</ref><ref>Christensen, L. R. (2008). The Logic of Practices of Stigmergy: Representational Artifacts in Architectural Design. In Proceedings of the 2008 ACM Conference on Computer Supported Cooperative Work (San Diego, CA, USA, November 8–12, 2008). CSCW '08. ACM, New York, NY, 559-568.</ref><ref>{{cite journal |last1=Christensen |first1=Lars Rune |title=Practices of Stigmergy in the Building Process |journal=Computer Supported Cooperative Work |date=2014 |volume=23 |issue=1 |pages=1–19 |doi=10.1007/s10606-012-9181-3|s2cid=2902658 }}</ref>

===Analysis of human social movements===
The rise of [[open source software]] in the 21st century has [[Disruptive innovation|disrupted]] the business models of some [[proprietary software]] providers, and [[open content]] projects like Wikipedia have threatened the business models of companies like ''[[Britannica]]''. Researchers have studied collaborative open source projects, arguing they provide insights into the emergence of large-scale peer production and the growth of [[gift economy]].<ref>{{cite journal |last1=Elliott |first1=Mark |title=Stigmergic Collaboration: The Evolution of Group Work: Introduction |journal=M/C Journal |date=2006 |volume=9 |issue=2 |doi=10.5204/mcj.2599|doi-access=free}}</ref>

===Stigmergic society===
[[Heather Marsh]], associated with the [[Occupy Movement]], [[WikiLeaks|Wikileaks]], and [[Anonymous (group)|Anonymous]], has proposed a new social system where competition as a driving force would be replaced with a more collaborative society.<ref>
{{Cite book|title = Binding Chaos: Mass collaboration on a global scale|publisher = CreateSpace Independent Publishing Platform|date = 2013-06-08|isbn = 9781489527684|language = en|first = Heather|last = Marsh|id =  {{ASIN|1489527680|country=uk}}}}</ref> This proposed society would not use [[representative democracy]] but new forms of idea and action based governance and collaborative methods including stigmergy.<ref name=":0">{{cite web|author = Heather Marsh|date = 2012-01-09|title = A proposal for governance: Stigmergy|url = https://georgiebc.wordpress.com/2012/12/24/stigmergy-2/|access-date = 2016-01-13|archive-url = https://web.archive.org/web/20160117235400/https://georgiebc.wordpress.com/2012/12/24/stigmergy-2/|archive-date = 2016-01-17|url-status = dead}}</ref><ref>{{cite web|author = Heather Marsh|date = 2011-12-24|title = A proposal for governance in the post 2011 world|url = http://wlcentral.org/node/2389|access-date = 2013-07-15|archive-url = https://web.archive.org/web/20130901090617/http://wlcentral.org/node/2389|archive-date = 2013-09-01|url-status = dead}}</ref><ref name="wlcentral.org">{{cite web|author = Heather Marsh|date = 2012-02-22|title = A proposal for governance: Concentric User Groups and Epistemic Communities|url = http://wlcentral.org/node/2464|access-date = 2013-07-15|archive-url = https://web.archive.org/web/20130831081838/http://wlcentral.org/node/2464|archive-date = 2013-08-31|url-status = dead}}</ref> "With stigmergy, an initial idea is freely given, and the project is driven by the idea, not by a personality or group of personalities. No individual needs permission (competitive) or consensus (cooperative) to propose an idea or initiate a project."<ref name=":0" />

Some at the Hong Kong [[Umbrella Movement]] in 2014 were quoted recommending stigmergy as a way forward.<ref>{{cite news |last=Leavenworth |first=Stuart |url=http://www.mcclatchydc.com/news/nation-world/world/article24776518.html |title=Hong Kong protesters, facing divisions, wait for police to act |work=McClatchy |date=2014-11-19 |access-date=2018-04-24 |quote=carrying a sign board for the “Stigmergy Society.” The term refers to the social organization of anthills, in which coordination isn’t achieved by a formal leadership structure but by independent action among those with shared goals. |archive-url=https://web.archive.org/web/20180425183115/http://www.mcclatchydc.com/news/nation-world/world/article24776518.html |archive-date=2018-04-25 |url-status=dead }}</ref><ref>
{{Cite web |title = Occupy Central - Part 1 |url = http://www.zonaeuropa.com/OccupyCentral_1.htm |website = www.zonaeuropa.com |access-date = 2016-01-13 }}</ref>

==See also==
* [[Ant mill]]
* [[Biosemiotics]]
*[[Extended mind thesis]]
* [[Path dependence]]
* [[Spontaneous order]]
* [[Watchmaker analogy]]
* [[r/place]]

==References==
{{Reflist|30em}}

== Further reading ==
{{refbegin}}
* {{cite journal |editor-last=Bonabeau |editor-first=Eric |title=Special issue on Stigmergy |journal=Artificial Life |volume=5 |issue=2 |pages=95–96 |date=Spring 1999 |issn=1064-5462 |doi=10.1162/106454699568692 |s2cid=35422936 |url=https://www.mitpressjournals.org/toc/artl/5/2}}
* {{cite journal |last1=Doyle |first1=Margery J. |last2=Marsh |first2=Leslie |year=2013 |title=Special issue: Stigmergy in the Human Domain |journal=Cognitive Systems Research |volume=21 |pages=1–74 |doi=10.1016/j.cogsys.2012.06.001 |s2cid=40609378 |issn=1389-0417 |url=https://www.sciencedirect.com/journal/cognitive-systems-research/vol/21}}
* {{cite journal |last=Elliott |first=Mark |date=May 2006 |title=Stigmergic Collaboration: The Evolution of Group Work |journal=M/C Journal |volume=9 |number=2 |doi=10.5204/mcj.2599 |url=http://journal.media-culture.org.au/0605/03-elliott.php |issn=1441-2616|doi-access=free }}
* {{cite journal |last=Heylighen |first=Francis |title=Stigmergy as a universal coordination mechanism I: Definition and components |journal=Cognitive Systems Research |volume=38 |year=2016 |issn=1389-0417 |doi=10.1016/j.cogsys.2015.12.002 |pages=4–13|s2cid=16431291 }}
* {{cite journal |last=Heylighen |first=Francis |title=Stigmergy as a universal coordination mechanism II: Varieties and evolution |journal=Cognitive Systems Research |volume=38 |year=2016 |issn=1389-0417 |doi=10.1016/j.cogsys.2015.12.007 |pages=50–59|s2cid=15095421 }}
{{refend}}

{{collective animal behaviour}}
{{World view}}

[[Category:Systems theory]]
[[Category:Self-organization]]