The short movie below shows a portion of an experiment in both visible (top panel) and infrared (bottom panel).  Filming in infrared allowed us to track the fish unhindered by the light gradients. The trajectories we obtained could be overlaid onto the projected light fields to calculate the gradient tracking ability and uncover the mechanism behind the collective taxis we observed.

Click here to view the embedded video.

You can also read more about the paper on:

• National Geographic’s Not Exactly Rocket Science
• Time
• Phys.org
• New Scientist
• NPR’s Science Fridays (video below)

Click here to view the embedded video.

Further information about the paper can be found here.

Here is a short movie summarizing our experiment:

Click here to view the embedded video.

Media coverage:

Ed Yong, Discover Magazine “To work out why fish swim together, tempt a predator with virtual prey”

Nell Greenfieldboyce, NPR “Swarming up a storm: why animals school and flock”

Akshat Rathi, The Economist “The benefits of schooling”

G.S. Mudur, The Telegraph, India “Fish spill group secret on video game”

Zoe Kleinman, BBC News “Fish play video game in new behavior study”

Jeffrey Matulef, Eurogamer.net “Princeton University develops videogames for fish”

Lee Rannals, RedOrbit “Simulations help scientists understand predator prey relationship”

Mark Brown, Wired “Predatory fish play video game to answer evolutionary quandry”

Children’s BBC (CBBC) Newsround “Video gaming fish help science”

Futurity “Video game for fish shows how prey survive”

Richard Chirgwin, The Register “Angry sunfish in piscine boss battles”

LiveScience “Fish video game reveals benefits of sticking together”

Phys.org “Video gaming fish play out the advantages of groups”

Click here to view the embedded video.

You can find out more by reading the full paper.

We make number 5 with the below paper, but what happened to our much more cited paper Couzin et al. (2005) “Effective leadership and decision-making in animal groups on the move” Nature? I contacted LabTimes and they kindly explained that their automated system did not pick up on it die to it having a shared UK and US address (Oxford and Princeton). Och well.

5. Couzin, ID; Krause, J; James, R; Ruxton,  GD; Franks, NR

Collective memory and spatial sorting in animal groups.

JOURNAL OF THEORETICAL BIOLOGY 218 (1): 1-11 SEP 7 2002

TO FIND OUT MORE AND TO APPLY PLEASE SEE THE WORKSHOP WEBSITE

This followed Iain’s Keynote address at the NVIDIA GPU Technology Conference:

http://smooth-las-akam.istreamplanet.com/live/demo/nvid4/player.html

Pedestrian crowds can form the substrate of important socially contagious behaviors including propagation of visual attention, violence, opinions and emotional state. However, relating individual to collective behavior is often difficult, and quantitative studies have largely employed laboratory experimentation. In the only previous study of gaze-following in human crowds, Stanley Milgram et al. (1969) instructed stimulus groups to stop and stare up into a building window on a crowded street in New York City, measuring the probability of passersby adopting this behavior. Although informative to the effects of social influence in public settings, these findings raise several interesting questions. What is the strength of this contagion response? What are the functional reasons pedestrians follow the gaze direction of others? Can cues provided by the visual attention of others provide valuable information regarding the location and identification of pertinent, but weak or ambiguous, stimuli? To what degree this is response context dependent?

OPEN ACCESS – See the full study by clicking HERE.

We performed two studies in which we used semi-automated analysis to track the motion and head direction of 3,325 pedestrians in natural crowds (see picture on the right and video below), quantifying the extent, influence and context-dependence of socially transmitted visual attention. In our first study we instructed stimulus groups of confederates within a crowd to gaze upwards towards a single point atop of a building. Analysis of passersby demonstrates that the probability of pedestrians adopting this behavior increases as a function of stimulus group size, before saturating for larger groups. This response has important consequences for how information about environmental stimuli is acquired socially between pedestrians. Many group-living animals use quorums (i.e., k>1) in response to the presence or behavior of others, allowing them to make consensus decisions in which all (or the majority of) individuals adopt the same choice. Conversely, the proportional-saturating response established here did not generate strong consensus. We developed a model that predicts this gaze response will lead to the transfer of visual attention between crowd members, but is not sufficiently strong to produce a “tipping-point” or “critical mass” of gaze-following that has previously been predicted for crowd dynamics.

This first experiment also showed that visual attention spreads unevenly in space. Individuals with trajectories leading them to walk behind the visual orientation of the stimulus group exhibited a higher propensity to follow the gaze of the stimulus group. This suggests that gaze-following under these conditions is not due to social pressure or some form of obedience. Instead, individuals followed gaze direction more often when the person they were copying could not observe their behavior. A similar rearwards transfer of visual attention has also recently been observed in bi-directional pedestrian traffic (Gallup et al., in press), suggesting that within natural settings gaze-following is strongly mediated by social interaction and facilitates acquisition of environmentally relevant information.

A second experiment, in which passersby were presented with two male confederates performing suspicious/irregular activity, supports the predictions of our model. Although pedestrians appeared to follow each other’s gazes towards the stimulus, and this was particularly the case for the suspicious-acting condition, there was no tipping point at which large numbers of individuals simultaneously gazed in that direction. Overall, visual interactions between pedestrians occurred primarily within a 2-meter range. This localized response, and the propagation of copying mainly by those not under observation of others, further reduces its the efficiency for transferring information about the location of weak signals or subtle features of the environment.

Click here to view the embedded video.

To explore the context dependence in this response, these experiments were performed in two urban settings – a busy shopping street and a bustling city train station. In the thoroughfare pedestrian gaze was drawn towards the suspicious actors at close distances, while in the train station gaze was drawn towards nearby control activity but averted from those exhibiting suspicious activity at very close positions. We hypothesize that aversion in a crowded commuter station consisting of largely stationary individuals could be because close proximity and directed gaze communicate threat or dominance. Further analyses indicated that male pedestrians accounted for this close range gaze-avoidance.

While the above aspects of gaze-following response are reproduced robustly between experimental setups, the overall tendency to respond to a stimulus is dependent on spatial features, social context and the sex of the passerby. In summary, this approach has produced quantitative and qualitative insights about a candidate causal link in the relation between individual and crowd behavior: the propagation of attention.

PRESS COVERAGE:

1. What are you looking at? People follow each other’s gazes, but without a tipping point (Discover Magazine)

BIBLIOGRAPHY:

1. Gallup, A.C., Hale, J.J., Garnier, S., Sumpter, D.J.T., Kacelnik, A., Krebs, J. & Couzin, I.D. (2012) Visual attention and the acquisition of information in human crowds. PNAS, published online April 23rd, open access.
2. Milgram, S., Bickman, L. & Berkowitz, L. (1969) Note on the drawing power of crowds of different size. Journal of Personality and Social Psychology 13, 79–82.
3. Gallup, A.C., Chong, A. & Couzin, I.D. (2012) The directional flow of visual information transfer between pedestrians. Biology Letters, published online March 28th.

Please note that these commentaries may contain views, or interpretation, not shared by the authors. We strongly encourage those interested to read the original paper – which can be downloaded for free from our publications page.

The first section of the supplement is also accessible for those wanting to know some more about the modeling and experimental protocols used. 

- As is emphasized in our title, this study is related to democratic consensus decision-making in animal groups such as schooling fish, flocking birds, herding ungulates etc. (this is not to be confused with democratic societies).

- We are not studying human voting systems in this paper, although the reader may note that we do demonstrate how group-living animals can effectively 'vote' without explicit ability to count etc.

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America votes with the fishes

Jeffrey Kluger, TIME

The Tea Party and the Occupy Wall Streeters owe a lot to a little fish called the golden shiner. Golden shiners are not very high on the aquatic food chain. They measure just 3 to 5 in. (7.5 to 12.5 cm) and serve as so tasty a finger food for bigger, more aggressive species that humans use them as bait fish. But the golden shiner can have strong opinions — deeply, fiercely held ones. And that, according to an improbable new study published in the journal Science, can tell us a lot about how American democracy works.

Read more: http://www.time.com/time/health/article/0,8599,2102612,00.html#ixzz1hGgQFrmF

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Vote for apathy?

Rob Waugh, The Daily Mail

 But a new Princeton study suggests that the opposite could be the case – and that people who have no interest at all could be vital to the working of a democratic society. The uninformed are essential to democracy because their apathy helps to dilute the effect of powerful minority interests – for instance, highly educated elites – who would otherwise dominate public life. A well-informed, interested public is often hailed as the 'ideal' of democracy.
Read more: http://www.dailymail.co.uk/sciencetech/article-2076026/The-uninformed-essential-working-democracy-study-finds.html#ixzz1hGfkN7PQ

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How ignorance could improve group decisions

Kate Shaw, Wired, 2011-12-16

How do groups of animals make collective decisions? Last week, we learned that bees reach consensus by headbutting those with opposing views. But in many other species, the decision-making process is a bit more democratic. In cases where social animals are unrelated and have different self-interests (such as our own), contrasting opinions are common. But it can be just as common for individuals to either be uninformed about the options, or simply not care much about the decision.

(more) 

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Disinterested 'key in democracy'

BBC.co.uk, 2011-12-16

Disinterested individuals are vital for achieving a democratic consensus, according to a study in the journal Science.

(more) 

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Why a democracy needs uninformed people

Emily Badger, Miller-McCune, 2011-12-15

In a lesson taught by schools of fish, researchers determine that uninformed individuals are actually a benefit to democracy by sanding off extreme views.

(more) 

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Uncommitted newbies can foil forceful few

Susan Milius, ScienceNews, 2011-12-15

Decisions can be more democratic when individuals with no preset preference join a group

(more) 

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Study of fish suggests the value of uninformed voters

Paul Basken, The Cronicle of higher education, 2011-12-15

As Congress proves itself increasingly dysfunctional and captive to extremists, lots of people may be asking themselves: What kind of fish-brained voters keep electing these guys?

(more) 

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Minnows reveal power of the 'uninformed'

AFP, ABC Science, 2011-12-15

It might sound fishy, but US researchers say minnows make perfect lab rats when it comes to exploring the surprising power of the uninformed in group decision-making.

(more) 

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Less Knowledge, More Power: Uninformed Can Be Vital to Democracy, Study Finds

Science Daily, 2011-12-15

Contrary to the ideal of a completely engaged electorate, individuals who have the least interest in a specific outcome can actually be vital to achieving a democratic consensus.

(more) 

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Ist Ignoranz wichtig für die Demokratie?

Eva Obermüller, ORF.at, 2011-12-15

Der mündige und informierte Bürger ist Grundlage jeder funktionierenden Demokratie, so die gängige Annahme. Eine Studie besagt hingegen: Unwissende, interesselose Individuen sind ebenso wichtig für den demokratischen Konsens.

(more) 

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Democracy may depend on the ignorant

Joseph Castro, LiveScience, 2011-12-15

Ignorance can be bliss, but it seems it can also promote democracy.

(more) 

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Can ignorance make a better democracy? In fish it can…

Joseph Castro, MSNBC.com, 2011-12-15

Minority can persuade majority, until the unknowing come along, study finds.

(more) 

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A democracy depends on uninformed individuals, maybe

Improbable Research, 2011-12-15

A democracy without a substantial number of uninformed individuals, may not know what it’s doing, metaphorically speaking. So implies this new study

(more)