I recently came across a word new to me; I’ll let Wikipedia explain it:

Stigmergy (/ˈstɪɡmərdʒi/ STIG-mər-jee) is a mechanism of indirect coordination, through the environment, between agents or actions. The principle is that the trace left in the environment by an action stimulates the performance of a next action, by the same or a different agent. In that way, subsequent actions tend to reinforce and build on each other, leading to the spontaneous emergence of coherent, apparently systematic activity.

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 lack any memory, intelligence or even individual awareness of each other.

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 στίγμα stigma “mark, sign” and 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.

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 by E. O. Wilson, from the Greek words σῆμα sema “sign, token”, and 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.”

I have several thoughts about this. It’s clearly a useful term, applicable to many kinds of things, so it’s good that Grassé created it (the OED entry, not updated since 1986, has this as its first citation: 1959 tr. P.-P. Grassé in Insectes Sociaux VI. 79   The stimulation of the workers by the very performances they have achieved is a significant one inducing accurate and adaptable response, and has been named stigmergy). It’s an ugly but well-formed word (in terms of its Greek derivation); the perceived ugliness will probably lessen as one sees it more and gets accustomed to it. The term sematectonic, on the other hand, is both ugly and unnecessary — the idea that because the Greek word ἔργον went into the makeup of stigmergy it must involve the concept of work and thus another word must be created for other uses is a typical example of the etymological fallacy, and I shake my fist in the general direction of E. O. Wilson (as I have done at other times for other reasons). At any rate, I will try to remember to make use of it when appropriate.


  1. Trond Engen says

    As if tectonic is less invocative of intended or physical action.

    And stigmaton is bleeding obvious.

  2. Wilson’s term is certainly ugly, but as regards unnecessary my verdict is “not proven”. Perhaps extending the original sense of stigmergy would have done, but OTOH perhaps the distinction between broad and narrow was important enough to merit a separate name.

    OTOOH Google suggests some sources distinguish “sematectonic stigmergy” from “marker-based stigmergy”, making sematectonic a subtype of stigmergy instead of vice versa.

  3. Sematectonic stigmergy (where changes to the thing providing the signal itself directly influence the behaviour of that same thing, such as amount of debris in an ant’s nest, movements of money markets, or bottom-up development of footpaths over lawns, etc) is often juxtaposed with marker-based or sign-based stigmergy, where different signals are added to the environment to influence future behaviour (the archetypal instance being use of pheromones for trail marking or nest building). This distinction can be found in Bonabeau et al’s classic 1999 book on the subject, though I don’t know whether they were the first to make it. We need a better term than ‘sign-based’ or ‘marker-based’, though, given that ‘stigma’ actually means ‘sign’ or ‘marker’!

  4. J.W. Brewer says

    Re “ugly and unnecessary,” I would also be concerned that “sematectonic” will in practice be understood by many budding specialists in the field (who may have less Greek than Wilson may have had) to mean approximately “semi-tectonic.” The opposition between hyper- and hypo-, which typically baffles non-specialist Anglophones, is used often enough in technical settings than it can be mastered as jargon by those in the relevant fields who have no Greek, but I suspect that sema- is not used widely enough to register as a morpheme. “Semiotics” and related words are I suspect largely understood by Anglophones who use them as undifferentiated and non-compositional wholes, i.e. with the constituent Greek morphemes being completely opaque and thus leading to no ability to generalize.

  5. Stu Clayton says

    How about “imitative”, in acknowledgement of Gabriel Tarde. Or “repetitious” i.a.o. Deleuze.

    That would allow us to avoid the control fantasies hidden in expressions such as “are added to the environment to influence future behaviour”. Tarde calls this merely “invention”.

  6. J.W. Brewer says

    I don’t spend that much of my time nostalgic about being a flat-broke and fancy-free college student in the 1980’s, but Stu namechecking Deleuze brings it all back … Random googling evokes memories of cheap rents and cheaper beer, e.g. “This article proposes a reading of Deleuze and Guattari that aims towards an approach of multisensory and processual ‘cinematic thinking’ to study audiovisual materials. The approach is then applied in a discussion about the recurrence of drug injection scenes in contemporary mainstream cinema.” Feeding oneself on five dollars a day, trying to avoid kicking over the full ashtrays on the floor, 19-year-old girls who had just been informed by some po-mo professor that the “phallus” was a “social construct” rather than an objective biological phenomenon. Good times!

  7. John Cowan says

    but I suspect that sema- is not used widely enough to register as a morpheme.

    Indeed. There is semaphore, but that is surely perceived as monomorphemic by most people, and I think it is the only word in sema- that is at all frequent. In semantics and friends the morpheme is semant-, and in the far less common semasiology and its relatives the morpheme is semasi-. I think you have to go to semateme, sematography, sematology before you get recognizable words in sema-, and they are extraordinarily infrequent.

  8. Only the word being so ugly has saved it so far from becoming the latest business buzzword, like synergy once was.

  9. Stu Clayton says

    Yeah, what happened to “synergy” in business-speak ? It has gone the way of shoulder padding, last seen on Grace Jones I expect. They’ll all return for a while in a retro wave, then be washed out to sea again.

    JW: my Saul moment came when I realized that socially constructed phalluses are constructed by dickheads.

  10. But it isn’t well-formed — it should be stigmatergy.

  11. Yeah, what happened to “synergy” in business-speak ?
    You seem to live in a nice corner of the business world if you don’t hear it any more. I still hear it frequently…

    my Saul moment came when I realized that socially constructed phalluses are constructed by dickheads
    That made my day. 🙂

  12. Stu Clayton says

    You seem to live in a nice corner of the business world if you don’t hear it any more

    Eheu! It has been replaced by other stupid-speak vocabulary.

  13. “Synergy” has been “disrupted”.

  14. AJP Crown says

    Stu: socially constructed phalluses are constructed by dickheads
    I’ll use this against the next nitwit with the insight that skyscrapers may be phallic symbols.

    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.

    I need a new expression that covers finding evidence of behaviour or physiological changes caused by work performed by other animals and, as a special case, evidence of the animals guiding additional work.

    Is that what he means? It’s horribly expressed. He should stick to ants.

  15. Stu Clayton says

    He had been reading too much German, I suspect. Though not Luhmann, of course. *That* would have put ants in his pants and an end to the blathering.

    Such ESL jello salad is itself a “general, non-work specific incitation”, namely to annoyance.

  16. But it isn’t well-formed — it should be stigmatergy.

    Damn, I guess you’re right. Let’s call the whole thing off.

  17. Stu Clayton says
  18. Rodger C says

    Stigmaturgy, actually. Digamma and all that.

  19. Huh? It’s energy, not enurgy.

  20. Stu Clayton says

    A demiurge works the people for all they’re worth.

  21. But it isn’t well-formed — it should be stigmatergy.

    Damn, I guess you’re right.

    No, wait, you’re wrong — it’s from στιγμός, not στίγμα. Well-formed after all!

  22. In that case it should be stigmurgy, shouldn’t it?

  23. Stu Clayton says

    It was a stigmurgeous, stormy night …

  24. Stigmurgy, from stigmourgia < stigmoergia < stigmowergia. Energy, from energia < enwergia. Cognate to 'work', you know. I'm now seeing three Brits testing cars.

  25. *-ergeia.

  26. AJP Crown says

    The Stig.

  27. στιγμός “pricking”, for which LSJ gives one example from Aeschylus? Seems unlikely.

  28. Don’t know what you mean by “unlikely”; OED says “Etymology: < French stigmergie (P.-P. Grassé 1959, in Insectes Sociaux VI. 62), < Greek στιγμός pricking + ἔργον work: see -y suffix3.” I don’t think they had to use their imaginations for a word coined in 1959; Grassé presumably explained it himself.

  29. I guess you’re right; I meant that the meaning of “stigma” seemed more suitable to what the term is intended to express.

  30. Ah well, he was an insect man, not a Hellenist.

  31. Talking of needing new expressions, I need something to describe the behaviour I’ve just watched in a supermarket carpark.

    Kinda the opposite of ‘stigmergy’; to paraphrase: a form of self-disorganization. It produces complex, seemingly stupid structures, without any planning, control, or direct communication between the agents. As such it supports dysfunctional outcomes between (otherwise) extremely intelligent agents, who lack any memory (that exactly the same happened last weekend), or even individual awareness of each other (that everybody drives to the supermarket at weekends).

    The outcome is logjam, but we don’t attribute intelligence or self-organisation to logs.

    The behaviour’s been modeled in the small by Social Scientists as The Prisoners’ Dilemma: two actors each making rational decisions in their own self-interest that combined has the worst outcome for both. But the Prisoners’ Dilemma relies on the actors being held incommunicado. Whereas each shopper knows everybody goes to the supermarket at the weekend; and that all going at the same time will be the worst.

    Car A is about to reverse out of its space. Car B sees this, and stops, not out of generosity to help Car A on its way, but because B has been circling the carpark for some time and knows this is likely to be the only available space. Car C (behind B) has to stop. Car D, E, F, … behind C also have to stop. … X also has to stop. X is going the opposite direction to B, along the narrow lane. X’s stopping blocks A from reversing out. Even if X realised what’s going on, it can’t back up because Y, Z are similarly jammed. Gridlock.

    This used to happen in Paris around L’Arc de Triomphe, when French roading had the stupid ‘priorite a droite’ system. The Flics were adept at shunting cars to/fro by millimetres to make enough space somebody (anybody) could get off the roundabout.

    Something similar seems to happen with loading passengers on to an aeroplane: despite the strenuous announcements at the boarding gate to first load people sitting at the back of the plane, everybody bundles into the scrum at the first announcement. Then the people sitting at the front seem to take an extraordinary time to self-(dis)organise themselves into their seats; leaving the back of the plane empty and a jam through the waiting lounge. I (being apparently a more intelligent actor) always wait until the last possible moment to board, even if my seat is at the back; and still there’s people queuing down the aisles.

    So are ants collectively more intelligent that humans collectively? Is there ever gridlock inside an ants’ nest?

  32. Stu Clayton says

    The outcome is logjam, but we don’t attribute intelligence or self-organisation to logs.

    There’s the mistake in your reasoning. Logjams are indeed self-organizing in the sense that they are “emergent phenomena”. You can’t predict them from the intelligence or stupidity of individual logs, bur they recur reliably.

    Similarly, the intelligence or stupidity of individual strawberries implies nothing about strawberry jam, although it can be reliably found on supermarket shelves.

    The pile-ups in parking lots and airplane aisles may be a Good Thing. Nature’s way of slowing us down so we don’t get burnout.

    Since those mass tramplings of each other by panicking fans at soccer games in the 80s, much research has been done into flow pattern factors such as placement of exits, design of corridors (they shouldn’t be straight and long). Great improvements have been made by adding choice here, constraints there.

    Parking lot jams can’t be blamed on stupidity alone. A few extra options would defuse the emergence, for example as provided by one or two thugs equipped with baseball bats. Their job is to threaten to smash the windscreens of selected drivers who don’t drive on or back up, depending on the situation.

    Something similar might be effective in cabin aisles.

  33. There’s the mistake in your reasoning. Logjams are indeed self-organizing …

    Ah! >lightbulb moment< That's what's always (until this moment of illumination) worried me about the Intelligent Design argument: if there's a Designer, how come the world is so stupid?

    So to explain logjams, we don't need to posit any more than that most trees are made out of wood. (As Spike Milligan used to tell us.)

  34. Stu Clayton says

    Well, spherical wood wouldn’t get into a jam. Long, cylindrical objects with slight protuberances (where the branches have been cut back) do. That is part of an explanation of why Velcro fasteners, paper and felt work, and why cats (their claws) get tangled in yarn. It might even explain strawberry jam if you go down to the molecular level.

  35. Stu Clayton says

    Quantum entanglement of strings prevents the world from falling apart.

  36. David Marjanović says

    Actually, that’s true.

  37. You’re just setting yourself up for a lecture about how there’s no such thing as truth.

  38. Stu Clayton says

    Haha, that’s old Hat ! The caravan of anarchy has moved on.

    Anyway, in forgetting the little I have in fact said you’ve confused “truth” and “reality”. I said the notion of reality is superfluous and misleading at best. I can’t remember having held forth on truth.

  39. Oh, I wasn’t thinking of any particular dictum, just remembering your general skepticism.

  40. Stu Clayton says

    I myself don’t think of it as skepticism, but rather as hygiene. I don’t like dusty answers on my plate.

  41. John Cowan says

    I haven’t flown in many years, but I’m told that at La Guardia, at least, the gate attendants won’t let you board if you are not in the section that’s boarding or one that’s further back in the plane.

  42. Stu Clayton says

    The same is true at German airports, at least with Lufthansa flights. Maybe discount vacationers are left to their own vices.

  43. David Marjanović says

    I’ve flown every year lately, and I don’t think many people ever try to board earlier than they’re supposed to.

  44. Lars (the original one) says

    In my experience, even if you stay in the gate area until staff threaten to close down the boarding card check, you will still find a queue in the ‘jet bridge’ (which word I just learned). The trick to eliminate frustrations is to keep the size of your carry-on luggage to what fits under the seat in front of you and treat the fight for space in the overhead lockers as a spectator sport. Mobile, book, wallet and hat is about right.

    Getting off, on the other hand — I prefer window seats because I can sit and read my book for up to ten minutes while all other passengers spring to their feet and fight to get their carry-ons from the lockers, crowding the aisle as tightly as possible. At least they will die standing if it gets too tight, there is no place for them to fall.

  45. Stu Clayton says

    That’s exactly what I do as well. I also have a few ruses for boarding an ICE and finding a seat. I prefer not to publish them, though, because their effectiveness depends on their not being shared with the ignorant multitudes.

    It’s odd that plane passengers are deaf and dumb to what happens around them, so you don’t have to fear that they will learn from you. Train passengers, however, are more devious and tend to learn faster.

  46. PlasticPaddy says

    Reminds me of the shaggy dog train joke about how to ride without a ticket, which ends when the hero (Paddy Irishman/Scotsman/Welsh man? ) approaches the closed door of the toilet where two slightly less devious (Paddy English men? ) people with one ticket are holed up and says “Ticket please” in his best conductor voice.

  47. That trick doesn’t work any more in the era of personalised tickets.

  48. Lars (the original one) says

    Well, I have never been asked to produce any form of ID when showing my personalized ticket on a train, but then I have never tried doing it while sat on the toilet.

  49. Well, requests to show an ID have become a regular thing on Deutsche Bahn trains.

  50. January First-of-May says

    Back in 2002, I actually managed to successfully ride with a personalized ticket under a different name – the main trick was that the relevant ID (birth certificate) didn’t actually have a photo, so the ticket checkers had no way to know of the switch.

    Background: Russian railways, at the time, had far cheaper tickets for children under 10. I was a few months over 10, but looked much younger. So my mom borrowed the ID of her friend’s 9-year-old son…

  51. Lars (the original one) says

    I made it from Copenhagen to Vienna two weeks ago without showing ID. First class, even. Of course I was wearing a hat, that instantly makes people trust you.

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