DENSITY AND CROWDING

DEFINITIONS OF DENSITY AND CROWDING

 

Density is the number of people in a prescribed space, for example, in a square kilometre. It is therefore a physical condition and can be separated into two types:

Crowding is the experience of the people in a given setting and is a subjective psychological concept. This means that feelings of crowding will vary from individual to individual as it involves a personal interpretation of the level of density. Therefore some people will feel 'crowded' more quickly than others.

It might be expected that situations of similar density would lead to the same reactions. However, there are a number of different factors that can affect how crowded an individual perceives a situation to be. These include:

·        . the relationship with the people involved

·        . the duration of the experience

·        . the physical context of the experience

·        . the meaning of the experience.

 

Types of crowds

Crowds may arise for a many different reasons, may be engaged in various activities and may be of differing sizes and compositions. The table below offers one classification of a range of crowd types based on their purpose or activities. Any one crowd may exhibit one or more of these types and may change type over time.

 

 Crowd type

Description

Example

 Ambulatory

Walking. usually calm

Shoppers on a pavement

 

 

during the Christmas

 

 

period

 Disabled. or of

Crowd has limited

A disability rights rally

 limited mobility

movement

 

 Cohesive/spectator

Shared interest of

Fans at a concert or

 

participants - for example.

sporting event

 

watching a specific activity

 

 Expressive/revelous

Emotional release

Spectators cheering in

 

 

unison or rejoicing after

 

 

an even t

 Participatory

Involved in an actual event

A community fun-run

 Aggressive/hostile

Initially verbal. open

Holiday-makers delayed

 

to lawlessness

at an airport

 Demonstration

A group that is organised

Pickets and protest

 

to some extent

marches

 Escape/trampling

Attempts to avoid real or

Emergency evacuations

 

imagined danger

following a fire alarm

 

 

or bomb scare

 Dense/suffocating

Reduction of individual

The crushing of a crowd

 

physical space such that

against barriers or in

 

movement is severely

narrow exits

 

impaired

 

 Rushing/looting

Attempts to obtain or steal

Ticket-holders rushing to

 

something

enter a concert that they

 

 

believe has started

 

 

without them

 Violent

Attacking or terrorising

Rioters setting light

 

others

to property

 

Based on Berlognghi (1993)

 

Fruin (1981) describes critical crowd densities - that is, the number of people per unit area - as a key characteristic in crowd disasters. Critical crowd densities are approached when the floor space per standing person is 1.5 square feet (0.14 m˛) or less. In a moving crowd, space restrictions limit mobility, worsening risks from crowding. At 25 square feet (2.3 m) per person, a stream of pedestrians can maintain normal walking speed and avoid one another. As space is restricted to 5 square feet (0.5 m˛) per person, speed is reduced - for example, people exiting a stadium or theatre are reduced to shuffling. By 3 square feet (0.28 m˛) per person involuntary contact is experienced between people, and at 2 square feet (0.18 m˛) per person potentially dangerous crowd forces begin to develop.

Natural animal studies

Dubos (1965) studied lemmings (small rodents that have short tails and fur covered feet) living in the Scandinavian mountain regions. It is well documented that every 3-4 years the lemmings go down to the edge of the sea and many of them fall over the edge and drown. This was believed to have been a biologically pre-programmed event to prevent overcrowding and limit their numbers. However, on closer examination, this research found that the event was frenzied with many of the lemmings dying accidentally. The researchers proposed that the reason for this was that their rapid reproduction led to a great increase in density which in turn influenced brain and adrenal functioning.

 

Another natural study carried out earlier by Christian, Flyger and Davis (1960) investigated Sika Deer on James Island, and came to a similar conclusion. They examined the records that were kept about the deer and found that initially in 1916 there had been four deer on the island. By 1955, this had increased to between 280 and 300 deer. However, three years later half of the deer had died, and by 1960 only 80 deer were left. The researchers were concerned by this sudden decline in the deer population, and post-mortems were conducted on the deer. They found that they appeared to have been in good shape with shiny coats and well developed muscles. However, their adrenal glands were ten times larger than normal, and after further testing to eliminate possible causes the researchers concluded that the adrenal glands were enlarged as a result of stress. This stress was believed to have been as a reaction to the crowding.

 

Experimental animal studies

 

Crowcroft, P. and Rowe, EP. (1958) The growth of confined colonies of the wild

house-mouse (Mus musculus L.): the effect of dispersal on female fecundity. Proceedings of the Zoological Society of London. 131. 357-65

Aim: To investigate the effect of the restriction of space on colonies of house mice, with particular respect to fecundity (reproductive capability).

Method: Seven colonies were established, each consisting of one adult male and two adult females. Each colony was housed in a pen with high metal walls and eight nest boxes measuring 6 feet (1.8 m) square. Some of these animals had access to much larger pens (more than 100 square feet [9.3 m˛]) after 32 or 40 weeks.

Results: In crowded conditions the mice populations increased and then levelled off. The failure to reproduce once a certain population density was reached appeared to be the result of non-­fecund (infertile) females. This did not appear to be a direct effect of stress as aggression was not observed between the females and none sustained injury. In crowded situations the female mice were found to have low fecundity because they could not be penetrated by the males and had inactive ovaries. In addition they had thread-like uteri and excessive fat deposits. Those animals that remained in crowded conditions did not return to a fecund condition, whereas colonies that dispersed into larger pens showed an increase in birth rate indicating a return to fecund status.

 

Conclusion: These results suggest that. For mice, at least, populations have a self-regulatory mechanism for limiting reproduction when the population density is high. This appears to act on the reproductive capacity of the females through a reversible change in their physiology and anatomy.

 

Some of these effects on fecundity described by Crowcroft and Rowe (1958) may have been a consequence of lack of exercise rather than crowding per se. Indeed, Schneider (1946) reversed the loss of fecundity in caged house-mice by introducing exercise wheels.

 One of the most famous studies into crowding was undertaken by Calhoun (1962) using Norway rats. Calhoun designed a 'rat universe' and in a series of six trials installed populations of Norway rats and watched what happened as population size increased. The rat universe consisted of a rectangular box, 10' X 14' in size, divided into four cells which could each house 12 rats in comfort. Each rat universe was provided with sufficient food and fresh water and nesting materials as required.

If the pens are spread in a line, it is obvious that cells Band C are really thoroughfares for all the rats and that A and D are the only pens with defensible space; that is, space which is defendable by the rats who live there.

The rats in each universe began to breed and were left alone until they reached 80 in number. At this point any infants that survived weaning were removed in order to maintain the numbers. Calhoun observed that once overcrowding occurred, the behaviour of the rats changed and the patterns of family groups which successfully raised their young no longer existed, especially in the middle pens.

The more dominant males claimed cells A and D and defended their territory, thus limiting numbers, and their behaviour was as normal as possible even though the pens were more crowded than normal. The remaining rats had to inhabit cells B and C which became known as the 'behavioural sink' and it was here that there was most evidence of both physiological and behavioural abnormalities. Both male and female behaviour in the sink changed considerably. Nest building and the rearing of young, although attempted, were inadequate, resulting in infant mortality rates as high as 96 per cent (compared with 50 per cent in the less-crowded pens).

The middle pens also produced four other groups of males. The first consisted of a number of very aggressively dominant males who constantly pursued oestrous females, fighting for the most dominant position. These fights resulted not only in battle wounds between the males, but on occasions in the wounding of females and young. This behaviour also led to a high rate of mortality from diseases in pregnancy with almost half the females in cells B and C dying by the sixteenth month of the study. The second group of males made advances to anything that moved, irrespective of its age or gender. The third group, on the other hand, was completely passive and ignored the other rats of both sexes. The final group was described by Calhoun as 'probers' and these were hyperactive, hypersexual, sometimes homosexual and occasionally cannibalistic.

Many of the effects on the rats can also be explained by Selye's General Adaptation Syndrome. Male rats in dense conditions produce fewer sperm and female rats start oestrus at a higher age, and their reproductive cycles occur less frequently and are of shorter duration than rats kept in much lower density conditions. This may well explain one way in which animals in the wild maintain optimum population size without the need to throw themselves into the sea!

The conclusions reached by Calhoun, that high density led to the observed changes in behaviour, has received considerable criticism. One of the biggest criticisms addresses the fact that he was not only studying the effects of high social density, but also territoriality. The rats in cells A and D had an environment which was easier to defend and therefore they were protecting their territory, whereas the rats in the centre two cells were severely disadvantaged. Perhaps an answer would have been to make each cell have a separate entrance and an exit so that all the rats were subjected to the same environmental conditions, and this would have removed the confounding variable of territoriality. It is also questionable whether these results relate to real-life situations because Calhoun manipulated a number of factors in the study. The first was removing any surviving young after the population reached the 80-rat level. The second was that in the wild, overcrowding would result in the rats leaving and finding a new environment and they were prevented from doing that in this study. In fact, in an earlier naturalistic observation, Calhoun had found that wild rats seemed able to limit population size according to available space without any human intervention. In defence of the study, other research with animals has provided similar evidence of behavioural change in terms of increased aggression and social withdrawal.

 

As a consequence of his findings, Calhoun (1971) proposed a mechanism by which crowding could have its effect upon animals. He suggested that each species has an optimal group size at which the individuals within it can tolerate the balance between beneficial and non-beneficial contacts with others. Beyond this size, the costs of social contacts (for example, competition and aggression) outweigh the benefits (for example, food sharing and ease of mate location).

 

EFFECTS OF DENSITY AND CROWDING ON HUMAN

HEALTH, SOCIAL BEHAVIOUR AND PERFORMANCE

Crowding and health

Researchers have examined the effect of increased social density on prisoners, as obviously they are unable to escape their environment and effects can be monitored over a period of time. McCain, Cox and Paulus (1976) researched the impact of different levels of density among prisoners and found that those inmates living in conditions of low social and spatial density were ill less frequently than those living in higher densities. They conducted further research and found that inmates who lived in higher density settings were more likely to suffer from high blood pressure and that high density was linked to higher death rates among prisoners.

Lundberg (1976) studied male passengers on a commuter train and compared high and low density conditions. There were enough seats for everyone even in the most crowded conditions. Urine samples were collected to measure for levels of adrenaline and higher levels were found after the high density journeys, suggesting increases in arousal and thus increases in stress. Further results found that regardless of how crowded, the train was, those who boarded at the first stop had lower adrenaline levels than those who boarded the train half way through the journey. Although their journey was longer, 72 minutes rather than 38 minutes, the control they experienced, by being able to choose their seats in an initially low density situation, led to them being able to cope with the higher density situation. Heshka and Pylypuk (1975) also conducted a study that took physiological measures following exposure to high density in the participants' natural environment. Levels of cortisol, a steroid compound produced by the adrenal cortex, were measured (as high levels of cortisol indicate high levels of stress). Students who spent the day in a high density shopping centre were compared with students who stayed on a relatively low density college campus. They found that males who had been in the high density situation had higher levels of cortisol than the control group, but females showed no difference.

Pandey (1999) asked participants living in high- or low-density areas of Gorakhpur City, India, about their health status. A positive relationship between crowding and illness was found; that is, people living in more crowded areas exhibited poorer physical and mental health. These people also reported a strong sensation of crowding (in other words, there was a positive correlation between objective crowding and feelings of crowding) and reduced perceived control. However, Chan (1999) tested 414 urban residents from the hyper dense metropolis of Hong Kong and found that residents in spatially constrained dwellings did not necessarily feel crowded. Where architectural designs met expectations - that is, the participants were satisfied with their physical surroundings - this helped to alleviate feelings of crowdedness.

Not only may high-density living conditions pose greater health risks, but it also seems to impair our ability to care for our own health. Menezes et al. (2000) studied a range of factors that could have been related to discharged psychiatric patients failing to comply with outpatient treatment. The only variable associated with poor compliance was residential crowding. Patients living in very crowded homes were twice as likely to miss outpatient appointments as those living in less-crowded homes.

 

People, privacy and perceived crowding

Baum, A. and Valins, S. (1977) Architecture and Social Behavior: Psychological

Studies of Social Density. Hilldale, NJ: Erlbaum

Aim: To investigate the balance between the benefits of increased opportunities to interact: as density increases and the costs of such enforced encounters.

 

Method: The perceptions and behaviour of occupants of two different types of university hall of residence were compared. The accommodation was either corridor-style or suite-style. Each offering the same amount of space per individual, the same number of individuals per floor and the same facilities (bathroom and lounge). They differed only in the number of other individuals sharing those facilities (either 4-6 in suites and 34 on corridors) and hence the number of different interpersonal encounters (in other words. the social density varied).

 

 

Results: Residents in corridor-style accommodation perceived their Floors to be more crowded. They were more likely to feel that they had to engage in inconvenient and unwanted social inter­actions and they expressed a greater desire to avoid other people. Their Feelings of helplessness were reflected in their social skills. They were less likely to initiate a conversation with a stranger were less able to reach a consensus after a discussion were less socially assertive and were more likely to give up in a competitive game.

Conclusion: Exposure to a large number of other people - especially when the group lacks social structure - has negative consequences, resulting in less sociable behaviour. The enforced uncontrollable personal contacts experienced by the corridor residents led to a feeling of helplessness. So they tended to avoid social interactions and were less assertive in ambiguous situations because they had learned that they had little control over their social environment.

 

 

Kaya, N. and Erkip, E. (2001) Satisfaction in a dormitory building: the effects of floor height on the perception of room size and crowding. Environment and Behavior. 33. 35-53

 

Aim: To investigate the effects of room location (Floor height) on students' perception of the size of their room and how crowded they felt.

Method: Residents occupying two dormitory blocks (one For men and one For women) at Bilkent University. Ankara. were studied. The identical Five-storey buildings contained identical rooms and had equal densities. The occupants were surveyed with regard to their perception of their room size, privacy and satisfaction.

 

Results: Residents on the highest Floor perceived their rooms to be larger and felt less crowded than residents on the lowest Floor. Participants who perceived their rooms as being larger expressed greater Feelings of privacy and were more satisfied with their dormitory rooms.

Conclusion: The perception of density as well as the actual density affect the sensation of crowding and hence satisfaction with accommodation.

Effects of social density in university residential environments

Baron, Mandel, Adams and Griffin (1976)

 

Aim: To examine the potential long term consequences of high density living on academic performance and health.

Participants: 144 male students from five high-rise university dormitories where unexpected tripling had occurred in rooms normally used as doubles. 102 were three to a room and 42 were two to a room.

Method: Participants were given seven different measures to complete in an hour. Five of these were in the hall study lounges. These were: a present living situation questionnaire, a comfortable interpersonal distance measure, a privacy scale, a past spatial history focusing on past living experiences and an internal-external locus of control scale. The other two measures: a room evaluation scale and a series of territorial maps were given in the individual dorm rooms.

Results: The major triple-double differences were as follows:

·        Evaluation of living space: triples rated their living space as more cramped and saw their rooms in more negative ways than doubles.

·        Self-perception of privacy and control: triples were less satisfied with their privacy and with the co-operation they received from their roommates in achieving privacy.

·        Interpersonal adjustment: triples perceived that they received less cooperation from roommates and were less satisfied with their roommates.

·        It was also found that triples visited the health centre more frequently but the difference was not significant. There were no overall significant differences in academic performance.

Conclusions: This study demonstrates that living in a high-density environment in the real world can have a negative effect on an individual's liking for others and also have a negative impact on their health.

 

Machleit, K., Eroglu, S. and Mantel, S.P. (2000) Perceived retail crowding and shopping satisfaction: What modifies the relationship? Journal of Consumer Psychology. 9. 29-42

 

Aim: To examine the relationship between retail store crowding and shopping satisfaction.

Method: A total of 1006 participants were used in two Field and one laboratory experiment to investigate the importance of high density on emotions and satisfaction.

Results: Shopping satisfaction was shown to be reduced by the emotions associated with crowding. However, this effect was moderated by expectations of crowding and personal tolerance for crowding. These relationships were found in both laboratory and field settings.

Conclusion: People who expect shops to be crowded and who are relatively tolerant of crowds are more likely to find shopping satisfying under high-density conditions than those who have less realistic expectations or are less tolerant.

 

Research has also been conducted in a more controlled environment to examine the effects of density. Evans (1979) carried out a laboratory experiment conducted with mixed sex groups of five males and five females in a three and a half hour study, in either a small room or a large room. Participants' heart rate and blood pressure were measured before the experiment began and again after three hours; it was found that in high density conditions participants had higher blood pressure and pulse rates than those in more spacious conditions.

 

Crowding and social behaviour Aggression

Lorenz (1950) proposed that aggression is innate and builds up within all species, both humans and animals, until something happens to trigger its release. Dollard et al. (1939) supported this idea with the frustration-aggression hypothesis which suggests that aggression only appears when we are frustrated in achieving some kind of goal. Perhaps living in high-density conditions from which we cannot escape produces frustration, and this may explain any relationship between density and aggression.

Evidence which indicated a relationship between density and aggression came from work with children who demonstrated higher levels of aggression in high-density play situations (Aiello et al., 1979; Ginsburg et al., 1977). However, further work indicated that density was not the cause and that it could be attributed to scarcity of resources. Rohe and Patterson (1974) found that high density produced more aggressive behaviour when the play situation failed to provide enough toys for the increased numbers of children, but when there were enough toys, increases in density had no effect on aggressive behaviours. Evidence with adults found some gender differences, with males generally becoming more aggressive with increases in density, but even these findings were inconsistent. Males rated themselves as more aggressive in small rooms (a situation of high spatial density), whilst the females rated themselves as more aggressive in large rooms (Stokols et al., 1973). However, when social density was manipulated and subjects had prior warning of possible crowding, neither gender acted aggressively and both tended to withdraw (Baum and Koman, 1976). These differences relate to the different personal space requirements of the genders.

Research has found that men in long-term high density situations such as prisons are more likely to demonstrate aggressive behaviour. Gifford (1997) describes research in the US into whether there was a relationship between the numbers of prison inmate assaults and the changing size of the prison population. He discovered that a 30 per cent reduction in prison population over a few months resulted in a 60 per cent drop in inmate assaults. The prison later increased its population by 19 per cent and this yielded a 36 per cent increase in assaults. Although there may have been other factors that influenced these results, research into aggression in psychiatric units in Sweden also discovered a relationship between social density and aggression (Palmstierna et al., 1991).

Research into aggression and crowding has found that in some cases high density leads to aggressive behaviour while other studies have found the reverse. This has led to the suggestion that both high and low density do not necessarily lead to aggression while moderate density does, suggesting an inverted U relationship.

 

Ehrlich and Freedman (1971) gave people various games to play, in varying sized rooms and found that the smaller rooms led to increased competitiveness and aggression, thus demonstrating the impact of spatial density. Palmstierna, Huitfield and Wistedt (1991) reported the effects of social density by looking at the behaviour of 163 acute care psychiatric patients over a 25 week period and found that the major predisposing factor to aggressive attacks was the number of patients around.

Many of the studies have found inconclusive results as they are not 'real world' studies. The short term nature of them makes the methodology very weak. However, it is difficult to study crowding in the real world other than using correlations between, for example, spatial density and crime statistics which suggest that there is a relationship between high density and some types of crime.

 

Attraction

The general finding is that high density leads to decreased attraction, both physical attraction and liking towards others. Research has also found that merely expecting higher density levels can lead to a reduction in attraction; Baum and Greenberg (1975) found that expecting to experience high social density was enough to elicit dislike. In their study, students who were told that they were waiting for ten people initially liked the people less than those who were told that they were waiting for four people.

There also appear to be gender differences in the impact that density has on attraction levels, with males experiencing a more extreme reaction. Epstein and Karlin (1975) conducted an experiment where males and females participated in same sex groups of six, solving puzzles. The participants were asked afterwards to say how similar they perceived the others to be. They found that males rated others more negatively in the high spatial density groups whereas females rated the others more positively in high density situations.

The differences in the levels of attraction shown by males and females' could be due to different personal space zones or to more co-operative socialisation of females and more competitive socialisation of males. This links to social norms, with it generally being seen as acceptable for females to discuss problems and support each other and as less acceptable for males to do this.

 

Research has suggested that one way in which individuals deal with high density is to withdraw from the situation. Withdrawal may occur in anticipation of the high density or as a reaction to it. The consequences of withdrawal due to density may be a disruption to social support networks. This in turn can have a negative effect as these are the networks we often rely upon during times of stress which are therefore not available. For example, Evans and Lepore (1993) found that individuals from crowded homes were less likely to seek social support when they needed it and rated others as less supportive than those from less crowded homes. Individuals from crowded homes were also less likely to offer support to others.

 

Helping

Much of the work that has looked at density and helping has been carried out in field studies which have obvious benefits over the laboratory research that has been carried out into other effects of density. It has been found that the greater the density the less the helping behaviour.

One field experiment that has been carried out with students was conducted by Bickman et al. (1973). They compared acts of helping behaviour in high, medium and low density dormitories. Envelopes which were stamped and addressed were dropped in the dorms and helpfulness was measured by the number that were picked up and placed in the mail. They found that 58 per cent mailed the letters in the high density dorms, 79 per cent in medium density dorms, and 88 per cent in low density dorms. This therefore demonstrates that more helping behaviour occurred in the lower density situations. Jorgenson and Dukes (1976) investigated social density and compliance in cafeterias. A notice was placed in the cafeteria asking people to return their trays, and they found that more people did this in low density conditions.

One reason why the level of helping behaviour may be reduced in crowded situations links to the concept of diffusion of responsibility. The more people that are present in a situation that requires help, the less often help is given. This may be due to the fact that people diffuse responsibility among themselves with no-one feeling that they ought to be the one to help.

 

Crowding and Task performance

Once again there have been a variety of studies carried out to test the impact that density has on task performance, including both laboratory and field experiments. It would seem likely that if density has a negative physiological effect and a negative effect on our social behaviour it will also have a negative effect on task performance. In a laboratory experiment, Paulus et al. (1976) found that both high spatial and social density led to decreases in complex maze task performance, with high social density having a greater effect than high spatial density.

Aiello, Epstein and Karlin (1975) conducted a field study looking at student dorms. They had two conditions: three people in a two person dorm (high density) or two people in a two person dorm (low density). They found that there was a decrease in complex task performance for the higher density condition.

 

This suggests that university students living in low density settings may get better marks than those living in high density settings. The increased density may overload an individual's information processing ability which in turn will lead to a poorer performance of tasks which require higher level cognitive skills.

A field study was also carried out by Saegert, MacIntosh and West (1975). They tested participants in a socially dense department store and at a busy railway terminal. One of the tasks was to produce a cognitive map of their environment, enabling them to give directions to others. The results showed that their ability to do this was impeded by the high density.

Similarly a field study was conducted by Bruins and Barber (2000) outside a supermarket. Eighty people were asked to take part at either crowded or uncrowded times. Findings demonstrated that the performance was worse, particularly for mental tasks, under crowded conditions.

 

Research has also found that there is the possibility that being in high density situations will have lasting after-effects. Evans (1979) found that participants who had been exposed to high density situations later showed less persistence at solving unsolvable puzzles than those who had been exposed to low density situations.

 

PREVENTING AND COPING WITH THE EFFECTS OF CROWDING

 

 

Preventing crowding

A number of factors linked to building design could affect the extent to which people feel crowded in a high density setting. First, it seems that having some space that an individual can claim to be her own, regardless of actual size, prevents the effects of density and leaves people feeling positive. For example, as described in the key study below, Cox et al. (1984) found that prisoners who had small single cells were more satisfied with their environment than those who had larger cells but had to share with another prisoner. Therefore when designing new buildings it may be beneficial to create more spaces for individuals rather than large communal areas to minimise the effects of high density living. Similarly Baum and Valins (1977) found that high-density accommodation that had been subdivided led to a reduced feeling of crowding. One reason for this is that the separation of the building into smaller units reduced the number of unnecessary social interactions and thus reduced some of the feelings of high density.

When planning new buildings, the size and shape of the rooms should be taken into account. Rectangular rooms tend to feel less crowded than square rooms, as do rooms where there are sufficient windows and doors. Curved rooms tend to feel more crowded as do high rise buildings. Therefore when designing new buildings it would be beneficial to take such, factors into account to attempt to satisfy the eventual inhabitants and hopefully reduce the potential feelings of crowding.

 

KEY STUDY

 

Prison crowding research

Cox, Paulus and McCain (1984)

Aim: To investigate the effects of crowding on inmates' physical and psychological health in state prisons.

Participants: Archival data from four prison systems, Illinois, Mississippi, Oklahoma and Texas on over 175 000 inmates was used alongside information collected directly from more than 2500 inmates.

Method: The prison environment was chosen as crowding, defined as aversive levels of density, was long-term, intense and inescapable. The prisons where the data were collected from ranged in population from 500 to 3000 and the housing units varied from spacious single rooms to densely populated dormitories for 70 or more inmates.

 

Results: Increases in prison population without a proportionate increase' in facilities are associated with an increase in rates of death, suicide and psychiatric problems while decreases in population are accompanied by a reduction of these factors and inmate on inmate attacks and self mutilations. Double cells led to negative effects on disciplinary infraction rates and illness complaint rates compared to single cells and open dormitory housing led to increased negative psychological reactions and increased illness-complaint rates compared to single or double cells.

Conclusions: Overall in a prison environment the greater the density the greater the negative effect. Therefore these findings have important implications for the design of prisons, in that providing inmates with some individual space will lead to positive effects both physically and psychologically. Coping with the effects of crowding

 Individual differences

Individual differences can have an effect on our ability to cope with crowding. For example, males are more likely to experience the effects of crowding than females, particularly in the short term, but may cope better in the long term. This could also be linked to an individual's preference for personal space. People with a need for a large interpersonal space are more badly affected in high density settings (Aiello, 1977). Men tend to like larger amounts of personal space, particularly when interacting with other men. The level of personal space required could also help to explain cultural differences in the ability to cope with crowding, as Mediterranean people experience the most negative effects when in a crowded situation.

Perceived control

The more control a person has over the crowded environment the less negatively they experience it, thus the perceived crowding is less. Schmidt and Keating (1979) identified three types of control:

·        . Behavioural control: having the ability to work towards a particular goal, for example, trying to limit the time spent in the high density situation.

They suggested that if one or more types of control were present there would be a reduction in crowding stress. Rodin, Soloman and Metcalf (1978) investigated perceived control and attempted to manipulate the amount of control people had in a lift. By observing people in the lift they found that there was a tendency to gravitate towards the control panel (i.e. trying to have some control). Therefore they manipulated whether or not people were able to stand near the control panel and found that those given control felt better and thought that the lift was larger when questioned afterwards. This suggests that if people feel that they have a choice, and have a feeling of control over the situation, the perception of the high density is not as negative.            .

Social conditions

The ability to cope with crowding is also influenced by the relationship the individual has with the other people in the situation. The high density will be interpreted less negatively if the individual experiences it with people he likes. This also raises the issue of the reason for the density. If people are sharing a pleasant experience, for example a concert, it is less likely to be perceived as crowded in a negative manner. Whereas, if people are experiencing density in an unpleasant situation, for example, trapped in a broken down tube train in rush hour, it is likely to be perceived negatively.

Coping strategies

One of the main coping strategies employed to limit the impact of high density is social withdrawal. This includes behaviours such as averting the gaze and using negative body language to attempt to block any potential intrusions. Evans et al. (2000) found that living in high density environments seems to predispose individuals to utilise social withdrawal as a coping strategy. Those people who have learned to use social withdrawal in their high density living are then able to use it as an effective coping strategy in other high density situations.

Further information

 

Acknowledgements

 

Sally Gadson, Philippe Harari, Karen Legge and Linda Sherry, 2005, Psychology A2 for OCR, Heinemann, 0-435-80671-8

Karon Oliver, 2002, Psychology in Practice, Environment, 0-340-84495-7

Craig Roberts and Julia Russell, 2002,  Angles on environmental psychology, nelson thornes, ISBN 0-7487-5978-6