Advanced mathematical models are used to predict the behaviour of large gatherings of people, making crowd movements and group mentalities more predictable than you might think, writes JOHN HOLDEN
WHILE MODERN sporting stadiums are designed to avoid tragedies such as the Hillsborough disaster that killed 96 people in 1989, the crowd rush at the Love Parade in Duisburg in 2010 – which caused 21 deaths – is an all-too-recent reminder that any large group in a small space can lead to trouble.
Organisers of the Olympic Games in London this summer will be aware of the risks and will apply crowd-control measures to marshal the thousands of people expected to attend.
Crowds seem to move in an inherently chaotic way but, in fact, the movement of large numbers of people is now being predicted by using advanced mathematical models. Psychologists are also studying crowd behaviour and changes to mental state for individuals within a large group. The goal is to avoid crowd disasters in the future.
“There are positives and negatives to being in a group,” says Dr Brian Hughes, a biological psychologist at NUI Galway. “One gets a superficial sense of solidarity and therefore well being. But it can also lead to the individual’s diffusion of responsibility. We are less conscientious. Individuals tend to leave things to other people.”
“When it comes to football, there is a theory that the level of rivalry felt by opposing fans is partly due to a perceived sense of immortality that being part of a club brings. There was a legacy there before you and it will be there after you. So it’s about outlasting your own lifetime. This makes people personally reckless.”
Groups tend to make less altruistic decisions and people within crowds tend to look after number one, which seems counter intuitive. “You would think that as part of a group you would feel more generous but, in actual fact, we’re more inclined to leave tasks to other people,” says Hughes.
“If a group of people walk past a homeless person on the street, they are less likely to give them any money than if it was just one person walking past. It goes back to the diffusion of responsibility.”
New research from the University of Limerick (UL) provides some useful insights into how the individual’s psyche can change in a crowd. “We recently completed a large project which examined collective national identity,” explains Prof Orla Muldoon of the UL Department of Psychology. “We looked at how Irish people behave at parades and various rituals which are used to represent the nation and the different ways we understand ourselves by how we behave at these events.”
The research studied events such as Queen Elizabeth’s visit, the 1916 Easter Rising commemorations and St Patrick’s Day, and found a number of variables – including proximity to opposing groups, knowing you’re being watched and a sense of dis-identification – which all play their part in terms of how the royal “we” behave when in a crowd.
When it comes to sporting events, such as international football matches, Muldoon is not surprised that tensions can be high. “There is a lot of ritual around football,” she says.
“The fact that the threat is explicit cranks up the tension several notches. We are hung on existing identities, people already feel Irish going into a game. They’re not just supporting the green football team.”
High-profile football games are deliberately designed to create as much tension as possible. “At a match between say Ireland and England or France and Germany, it is little wonder that there can be trouble,” says Muldoon.
“The fans are coming in with any history between the two nations on their minds, everybody is trapped in a very small space and you can see and engage with the opposing group. It is the highs and lows of the game that motivate fans to engage physically with their team. That’s also part of the beauty: people are getting joy, marked against maybe very heavy negativity.”
Muldoon and her team did find, however, that those who actively engage with the perceived “enemy” will enjoy positive psychological benefits. “People who have positive engagements with the opposing side do tend to have better psychological wellbeing subsequent to participation,” she says.
Anyone who has ever regretted doing karaoke in public will know that being watched can have a significant impact on your behaviour. Many professional athletes, for example, rise to these occasions. For lesser mortals, however, it can lead to us being willing to perform only the simplest of tasks. This relates to the “drive theory of facilitation”.
“Knowing you’re being watched fundamentally changes your behaviour,” says Hughes. “It tends to increase drive, heart rate, blood pressure and, in a general sense, makes you more reactive to what’s going on around you. Specifically, the way it manifests itself is that it lends [itself towards] natural reactions rather than complex reactions. According to the theory, simple behaviours become dominant while complex behaviours become less so. Being boisterous comes naturally when you’re being watched.”
On the flipside, if you observe stadium etiquette, you’ll see that if a sport is simple, such as running, the crowd will make themselves heard. If the sport is deemed complex, such as gymnastics or snooker, the etiquette is to stay quiet and remain in the background.
Putting our own behaviour to one side, plenty of practical research has been done in looking at how best to manage large groups to keep them safe. What normally causes people to feel anxiety and therefore lead to panic, trouble or riots, is a sense of a lack of control. If there is any sense of ambiguity at an event as large as the Olympics or Euro 2012, panic will spread.
“Things need to be made very clear for people,” says Hughes. “In modern sporting stadia, everyone has a seat number allocated to them, which was not always the case. This clarity seems to have had a very positive effect on people’s behaviour.”
Much of the research that goes into crowd control is kept secret. “People who design crowd-control solutions feel it’s commercially sensitive,” says Hughes. “There is a lot of private research being carried out on the flow of people, their natural direction around angles and group movements, to try and minimise risk factors for crowd unrest at a basic ergonomic level.”
Finding order among the chaos
IS THERE ANY order behind the apparent chaos of people moving along Dublin’s Grafton Street on a Saturday afternoon?
Physicists can take some of the models they use to study the movement of particles and apply them to humans also.
“Our movements are governed by a number of things,” says Prof Stefan Hutzler of Trinity College Dublin’s Department of Physics.
“Mass, gravity and electromagnetic forces all play their part. Given these forces and masses one can work out how any particles will move in time and we can then work out their trajectory.”
Some other basic rules apply to being a successful pedestrian. “Unless we’re drunk we will always try to walk in a straight line,” says Hutzler. “We walk at our own ideal velocity or comfortable speed. If there is an obstacle on the road, we walk around that obstacle. It is as if the obstacle exerts a force on you, not a physical force but a force that needs to be avoided, which then brings you off your straight path so to speak.”
Looking at Grafton Street from above, one will observe how people naturally walk in lanes. “Some are going up the street, some are going down, but the lanes form automatically with no signs saying you have to walk behind others,” he says.
“Computer simulations can reproduce this type of lane behaviour. Another example is at an entrance to a store or on the Luas. People go in then some people go out. There’s an oscillation taking place which can be recreated with a very simple simulation.”
This discipline, known as sociophysics, has even looked at annoying human behaviour. “If you’re getting tired of waiting in a line, say at an ATM, very often you’ll take a step forward closer to the person in front of you. It’s completely pointless because you wont be served any quicker, but you do it anyway. This effect is also being incorporated into computer models for human movements.”
As useless as this information may appear, it is essential for modern commercial architectural design. “Simulations have shown us, for example, that for human- traffic flow, it is more efficient to have two doors into a building rather than just one large door,” says Hutzler. “They don’t need to say entrance and exit above them. People will naturally follow others in or out.”
