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The Rules of the Swarm

Hugh Pickens writes "Researchers are starting to discover the simple rules that allow swarms of thousands of relatively simple animals to form a collective brain able to make decisions and move like a single organism. To get a sense of swarms, Dr. Iain Couzin, a mathematical biologist at the Collective Animal Behaviour Laboratory at Princeton University, builds computer models of virtual swarms with thousands of individual agents that he can program to follow a few simple rules. Among the findings are that swarm behavior has patterns common to many different species, that just as liquid water can suddenly begin to boil, swarm behavior can also change abruptly in character, and that just a few leaders can guide a swarm effectively by creating a bias in the swarm's movement that steers it in a particular direction. The rules of the swarm may also apply to the cells inside our bodies and researchers are working with cancer biologists to discover the rules by which cancer cells work together to build tumors or migrate through tissues. Even brain cells may follow the same rules for collective behavior seen in locusts or fish. "How does your brain take this information and come to a collective decision about what you're seeing?" Dr. Couzin says. The answer, he suspects, may lie in our inner swarm."

37 of 166 comments (clear)

  1. I live for the swarm by stoolpigeon · · Score: 4, Funny

    Spawn more overlords.

    --
    It's hard to believe that's how Micronians are made. Why don't we see it right now by having you both kiss one another?
    1. Re:I live for the swarm by UnderDark · · Score: 4, Funny

      Can not build more Overlords: More minerals required!

  2. Strength is irrelevent by Wonko+the+Sane · · Score: 2, Funny

    You will be assimilated

    1. Re:Strength is irrelevent by jagdish · · Score: 2, Funny

      Jesus is returning, Resistance is futile.

  3. it's funny because it's true by User+956 · · Score: 4, Funny

    Researchers are starting to discover the simple rules that allow swarms of thousands of relatively simple animals to form a collective brain able to make decisions and move like a single organism.

    Strangely enough, it also explains republican voting habits.

    --
    The theory of relativity doesn't work right in Arkansas.
    1. Re:it's funny because it's true by Anonymous Coward · · Score: 3, Funny

      I'm sorry but I'm pretty sure that there is some kind of new law that says you can't write this kind of response without mentioning Ron Paul.

    2. Re:it's funny because it's true by DigiShaman · · Score: 4, Insightful

      That's right, keep the Republican jokes comming. Typical Slashdot "Swarm-think".

      Hey, I just discovered something...

      --
      Life is not for the lazy.
    3. Re:it's funny because it's true by c6gunner · · Score: 4, Funny

      If slashdot were a swarm of bees, it would long ago have committed suicide by repeatedly attempting to mate with a toaster.

      "Ohh! Shiny gizmo!"

      *BZZZZT*

      "....what do you think happened to him?"
      "who cares? look at the shiny gizmo!"

    4. Re:it's funny because it's true by innerweb · · Score: 2, Interesting

      For our next trick, we will quote Rush Limbaugh and Howard Stern as principles of honesty and integrity in reporting.

      Group think is really a misnomer. Group think is really a large bunch of individuals not thinking (or thinking at a minimal level). So, republicans, democrats, libertarians, religious assemblies, whatever, is just minimal thinking individuals participating in groups guided by a few individuals in swarm behavior. It really does make so much sense this way. It has almost always worked when marketing. That is why marketers want a buzz about their ads and products, it promotes a swarm (mob) mentality about the product in question.

      It is funny, but I think this will have more impact on marketing in the next 10 years than anything else.

      InnerWeb

      --
      Freud might say that Intelligent Design is religion's ID.
    5. Re:it's funny because it's true by Greyfox · · Score: 3, Insightful

      Republican jokes aside, if crowd behaviors on a large scale are provably predictable with swarm rules, what does that say about individual free will? We like to think we have it but in the grand scheme of things I don't think we're any smarter than ants.

      --

      I'm trying to teach myself to set people on fire with my mind... Is it hot in here?

    6. Re:it's funny because it's true by The+Raven · · Score: 2, Interesting

      Overtones of Psychohistory. Luckily, later research into chaos and information theory has pretty much ruled out the possibility of Psychohistory being real.

      --
      "I will trust Google to 'do no evil' until the founders no longer run it." Hello Alphabet.
  4. Gaia? by ynososiduts · · Score: 2, Insightful

    Maybe they are each part of the same consciousness? Have you not read Foundation's Edge?

    --
    622677120
  5. Just like fractals by Gabest · · Score: 5, Interesting

    We are already "cells" of a thing called "economy", for an alien the earth may just look like a single living being.

    1. Re:Just like fractals by Explodicle · · Score: 2, Informative

      We are already "cells" of a thing called "economy", for an alien the earth may just look like a single living being. See also: Gaia hypothesis.
  6. First rule of the swarm by PPH · · Score: 2, Funny

    Nobody talks about the swarm.

    --
    Have gnu, will travel.
  7. The Rules of THE SWARM by Null+Perception · · Score: 4, Funny

    1st RULE: You do not talk about THE SWARM. 2nd RULE: You DO NOT talk about THE SWARM.

    --
    Great new book on Evolution: The Greatest Show on Earth by Richard Dawkins
  8. Rules of the Swarm by Misanthrope · · Score: 4, Funny

    Swarm Subtype

    A swarm is a collection of Fine, Diminutive, or Tiny creatures that acts as a single creature. A swarm has the characteristics of its type, except as noted here. A swarm has a single pool of Hit Dice and hit points, a single initiative modifier, a single speed, and a single Armor Class. A swarm makes saving throws as a single creature. A single swarm occupies a square (if it is made up of nonflying creatures) or a cube (of flying creatures) 10 feet on a side, but its reach is 0 feet, like its component creatures. In order to attack, it moves into an opponent's space, which provokes an attack of opportunity. It can occupy the same space as a creature of any size, since it crawls all over its prey. A swarm can move through squares occupied by enemies and vice versa without impediment, although the swarm provokes an attack of opportunity if it does so. A swarm can move through cracks or holes large enough for its component creatures.

    A swarm of Tiny creatures consists of 300 nonflying creatures or 1,000 flying creatures. A swarm of Diminutive creatures consists of 1,500 nonflying creatures or 5,000 flying creatures. A swarm of Fine creatures consists of 10,000 creatures, whether they are flying or not. Swarms of nonflying creatures include many more creatures than could normally fit in a 10-foot square based on their normal space, because creatures in a swarm are packed tightly together and generally crawl over each other and their prey when moving or attacking. Larger swarms are represented by multiples of single swarms. The area occupied by a large swarm is completely shapeable, though the swarm usually remains in contiguous squares.
    Traits

    A swarm has no clear front or back and no discernable anatomy, so it is not subject to critical hits or flanking. A swarm made up of Tiny creatures takes half damage from slashing and piercing weapons. A swarm composed of Fine or Diminutive creatures is immune to all weapon damage. Reducing a swarm to 0 hit points or lower causes it to break up, though damage taken until that point does not degrade its ability to attack or resist attack. Swarms are never staggered or reduced to a dying state by damage. Also, they cannot be tripped, grappled, or bull rushed, and they cannot grapple an opponent.

    A swarm is immune to any spell or effect that targets a specific number of creatures (including single-target spells such as disintegrate), with the exception of mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects) if the swarm has an Intelligence score and a hive mind. A swarm takes half again as much damage (+50%) from spells or effects that affect an area, such as splash weapons and many evocation spells.

    Swarms made up of Diminutive or Fine creatures are susceptible to high winds such as that created by a gust of wind spell. For purposes of determining the effects of wind on a swarm, treat the swarm as a creature of the same size as its constituent creatures. A swarm rendered unconscious by means of nonlethal damage becomes disorganized and dispersed, and does not reform until its hit points exceed its nonlethal damage.
    Swarm HD Swarm
    Base Damage
    1-5 1d6
    6-10 2d6
    11-15 3d6
    16-20 4d6
    21 or more 5d6
    Swarm Attack

    Creatures with the swarm subtype don't make standard melee attacks. Instead, they deal automatic damage to any creature whose space they occupy at the end of their move, with no attack roll needed. Swarm attacks are not subject to a miss chance for concealment or cover. A swarm's statistics block has "swarm" in the Attack and Full Attack entries, with no attack bonus given. The amount of damage a swarm deals is based on its Hit Dice, as shown in the table.

    A swarm's attacks are nonmagical, unless the swarm's description states otherwise. Damage reduction sufficient to reduce a swarm attack's damage to 0, being incorporeal, and other special abilities usually give a creature immunity (or at least resistance) to damage from a swarm. Some swarms

  9. The Rules of the Swarm... on slashdot. by Willbur · · Score: 5, Insightful

    When I read the summary my immediate response was that this was old news. It has been known for quite a while that cellular automata with simple rules can form universal Turing machines. That means that they can "form a collective brain" and "make decisions and move like a single organism". The interesting question then becomes; What "program" is your machine running, and how do you make it robust so that it works in the real world (with all the noise of nature)?

    The article is a popular science article, but addresses this, more interesting, question much more than the summary. They discuss some of the rules involved in specific situations (ants), and even look at "human swarms" (although that bit is a little cheesy). There is no general theory posited about how to make these rule sets though, apart from trial and error (in simulation if you can). They say that the researchers are starting to see patterns, but don't talk about what those patterns are - pity really, as that would have been very interesting.

    1. Re:The Rules of the Swarm... on slashdot. by catmistake · · Score: 2, Interesting

      ~160 years ago, Søren Kierkegaard worked out the First Philosophy of the human swarm:
      The crowd is untruth.

    2. Re:The Rules of the Swarm... on slashdot. by m0nstr42 · · Score: 2, Interesting

      The article is a popular science article, but addresses this, more interesting, question much more than the summary. They discuss some of the rules involved in specific situations (ants), and even look at "human swarms" (although that bit is a little cheesy). There is no general theory posited about how to make these rule sets though, apart from trial and error (in simulation if you can). They say that the researchers are starting to see patterns, but don't talk about what those patterns are - pity really, as that would have been very interesting.
      Check out Dr. Couzin's web site: http://www.princeton.edu/~icouzin there are lots of great papers there.

      One common set of rules is (related to boids) 1. Move away from those closest to you. 2. Move towards those farthest from you. 3. Align with those in the middle.

      On the other hand, it would be erroneous to posit a common set of rules for every species. Different evolutionary pressures produce different behaviors in different situations. An interesting facet of this type of research is to see how different sets of parameters for the same set of rules can produce different behaviors, or different sequences of behaviors.
    3. Re:The Rules of the Swarm... on slashdot. by skiingyac · · Score: 2, Interesting

      I can't speak for him directly, but I've been to one of his talks and read a bunch of his papers. Basically, the 3 rules for bird/fish/etc movement are very simple and are surprisingly robust. But, it is extremely difficult to reverse-engineer the rules. Sure, those 3 rules are simple enough, but are they the ones actually used by the animals? You can't exactly ask them. And then there are questions about whether an individual gives more weight to a neighboring individual which it can only hear and not see (because it is behind them), or to what extent an individual's own sense of direction and instincts plays a part. Animals have tons of senses, each with tons of dimensions.

      Then there are behaviors like in geese where if one goose in a migrating flock is injured/sick/tired/dying, another goose will leave the flock (the rest of which continues on) and this other goose waits until the first goose is better (or dies) and then they continue the migration. What is the rule for that? It is just as hard to fine-tune a given set of rules except via experiment/simulation since there's not much mathematical theory behind this yet (though I believe he's got some started).

      Then there are things like, we'd like to make robot swarms and we want them to act like birds except do X instead of Y. Even if the natural behaviors are modeled it is very difficult to figure out what rules to add/change/delete to get the desired change. Or, we want the robots to do natural thing X, but we need some guarantee that they will do it with some level of accuracy and we need a kill switch in case they become self-aware. This field is wide open and is extremely interesting, because even if we're not explicitly mimicking natural phenomenon we are anyway when we have groups of things (computerized or otherwise) that have many individual components with complex and somewhat autonomous interactions.

    4. Re:The Rules of the Swarm... on slashdot. by m0nstr42 · · Score: 2, Informative

      Then there are things like, we'd like to make robot swarms and we want them to act like birds except do X instead of Y. Even if the natural behaviors are modeled it is very difficult to figure out what rules to add/change/delete to get the desired change. Or, we want the robots to do natural thing X, but we need some guarantee that they will do it with some level of accuracy and we need a kill switch in case they become self-aware. This field is wide open and is extremely interesting, because even if we're not explicitly mimicking natural phenomenon we are anyway when we have groups of things (computerized or otherwise) that have many individual components with complex and somewhat autonomous interactions.
      Check out http://www.princeton.edu/~naomi You will find several papers co-authored by Iain.

      We apply tools like nonlinear control theory and graph theory to study these kinds of "rules" with rigor, with the aim of a) designing robotic (specifically mobile sensor) networks that are bio-inspired in the way you mentioned and b) help the biologists by providing insight from our perspective.
  10. Stand Alone Complex? by necro2607 · · Score: 2, Interesting

    "... just a few leaders can guide a swarm effectively by creating a bias in the swarm's movement that steers it in a particular direction"

    Wow, did this remind anyone else somewhat of Ghost In The Shell: Stand Alone Complex and the Laughing Man and Individual Eleven cases? Plus there is plenty of discussion throughout the series about how subtle influence by a select few can affect the whole of society, unnoticed. I know it's a bit different, but it's kind of unreal to be hearing about this in the news after having only just recently watched the two seasons of Stand Alone Complex episodes...

  11. *cough*cough* by yusing · · Score: 2

    My inner swarm tells me to suspect the validity of this concept when applied to educated individuals running free-will simulations.

    Not to mention my inner hippy.

    --

    "You must try to forget all you have learned. You must begin to dream." -- Sherwood Anderson

  12. algorithms by cynicsreport · · Score: 5, Informative

    There are several very interesting optimization algorithms based on swarm behavior, such as particle swarm optimization and ant colony optimization. These methods have a similar ability for non-linear optimization (and pattern recognition) as neural networks.

    --
    - Demosthenes
    cynicsreport.com
  13. Re:I'm sure in some deep, dark basement by BCGlorfindel · · Score: 2, Funny

    Stephan Wolfram is going "I told ya so."

    Wouldn't that be more like "WE told ya so".

  14. Locusts and cannibalism by FleaPlus · · Score: 5, Interesting

    Cool to see Couzin on slashdot... I coincidentally saw a talk of his last week and gave him a brief lab tour. His own research is somewhat outside my area, but one of the most surprising things I recall from his talk is that marching locust swarms are apparently propelled by cannibalistic behavior. If I'm remembering correctly, baby locusts (before they've grown wings) in a region will feed in a pretty disorderly fashion. However, once salt and protein supplies start running low, they get hungry and start trying to eat each other. The researchers realized this when the locusts in their enclosure seemed to be mysteriously disappearing at a steady rate, due to being consumed by their peers. ;)

    In any case, once they start eating each other, the locusts start trying to chase the locusts in front of them, while simultaneously avoiding the locusts behind them trying to eat them. The emergent behavior is that the entire swarm moves as a mass until a new area is found where salt and protein supplies are plentiful enough to cause them to switch out of cannibalism-mode. This presumably has a number of ramification on how to control migration of locust swarms, which are an immense destroyer of food resources in the developing world.

    1. Re:Locusts and cannibalism by m0nstr42 · · Score: 2, Informative

      My favorite thing about Dr. Couzin is his willingness to work with people in other disciplines - particularly the "harder" sciences. It's mentioned towards the end of the article. My advisor, Naomi Leonard, and her students have published several papers with Iain as a co-author - see http://www.princeton.edu/~naomi/ and search for "Couzin" and "Levin" on the page for a few references. Dr. Grunbaum, who is also mentioned in the article, is great with this as well (also on the page). They are both fantastic guys to work with.

      And a shameless plug for my tiny contribution - http://www.princeton.edu/~dswain/publications/2007/DSCDC07.pdf

  15. Swarm simulations? by FlyingSquidStudios · · Score: 2, Informative

    I would like to welcome Slashdot to 1986.

  16. leaders and bias in swarm? Marketers. by Sir+Holo · · Score: 5, Funny


    and that just a few leaders can guide a swarm effectively by creating a bias in the swarm's movement that steers it in a particular direction.

    In human populations, we call those marketers.

  17. Re:Water never by exp(pi*sqrt(163)) · · Score: 4, Insightful

    There's a distinct phase transition that forms a discontinuity. Here are some Phase diagrams showing how state depends on pressure and temperature. The point is that you don't get a continuous transition between liquid and gas, say, with a half-liquid/half-gas state. Phase diagrams exhibit distinct lines separating quite distinct regions. The idea here is that maybe swarms also have these kinds of discontinuous phase transitions.

    --
    Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
  18. Re:Boids by m0nstr42 · · Score: 2, Informative

    I didn't RTFA, but I wonder if the guy's work is related to an old artificial life simulation called Boids. The developer of Boids was able to model the flocking behavior of birds by formulating some relatively simple rules. When I first learned about the program, it sounded really neat, and according to Wikipedia it's still used in computer graphics to model flocking behavior.
    The rules are quite similar, but the treatment is different. Boids was an artificial life simulation experiment. The stuff TFA refers to is intended as a simplified model of a set of mechanistic rules to describe animal behavior. The parameter space is explored with the goal of discovering behaviors that may be argued to have analogs in actual animal groups.
  19. Re:Collectively, of course by Tribbin · · Score: 3, Insightful

    You got it all WRONG!!!

    A swarm has no overlord!

    --
    If you mod this up, your slashdot background will turn into a beautiful sunset!
  20. probably applies on macro scale too by lashi · · Score: 2, Insightful

    rules of the swarm applies to more than just simple creatures. it probably can be used to study our society, mass hysteria, war, religion.....

  21. these are models... what about experiments? by dummkopf · · Score: 2, Informative

    Currently, Physics Today has an article about the swarming of birds. The studies from the group in Rome are expected to complement current models since currently there is little experimental evidence to back up the models. Using several cameras they take time-lapse pictures of the swarms and then reconstruct the complex trajectories on the computer (a tour de force...).

  22. Background paper by sTeF · · Score: 2, Informative
    I recently read one of his papers: Collective Memory and Spatial Sorting in Animal Groups. It is a great read, the most interesting results? states of individuals have an effect on the swarm, you don't have to be aware even of the swarm, simple parameters such as perimeters, closeness to other swarm individuals can have a dramatic effect.

    the other interesting result is, that the next state of the swarm can depend on states in the past, this leads to spatial memory effect.

  23. They're called... by FlopEJoe · · Score: 2, Funny
    What do you call thousands of relatively simple animals that form a collective brain?

    Politicians.