|Vulnerability and Risk Assessment - 2nd Edition (Department of Humanitarian Affairs/United Nations Disaster Relief Office - Disaster Management Training Programme - United Nations Development Programme , 1994, 70 p.)|
|Part 1 - Understanding risk|
The key to a successful program to reduce risk is to understand the importance that society attaches to the hazards that confront it, that is to say on its own perception of risk.
Decisions have to be made about risks, even if that decision is to do nothing about it. In most societies, several groups are involved in these decisions; in particular:
The general public
Their political representatives
The experts, communicators and managers
In principle, experts gather the scientific and socio-economic evidence and give technical advice to the politicians, who then legislate and regulate for the benefit and with the implicit agreement of the general public. In practice, of course, things do not very often work out that way. Assessing risk from the available data is not always as helpful as the experts would like. Politicians can have interests and objectives in decisions other than the simple consideration of risk mitigation, and the general public may not see things the same way as either the experts or the politicians.
Decisions are made and actions are taken according to the way that risks are perceived. Perception of risk can differ from one group to another. Experts like to use statistics. But most other people are less comfortable with statistical concepts and prefer to base perceptions of risk on a range of other values, philosophies, concepts and calculations.
Perception of risk has been an important area of psychological research. The mental process of evaluating risk - making sense out of a complex collection of different types of information - tends to differ significantly between individuals and groups. Rules of judgement may be evolved within one group which can lead to valid and consistent decisions, but which may be significantly different from those of another group or individual that has used different patterns of thought to evaluate the same set of facts. Similar differences exist between the individuals within any group.
Risk and the media
An important element in the psychology of risk perception is the 'availability' of information. The mental strategy for decision-making is to match a situation under review with the information that is most readily available and easily recalled. The more 'available' the information on a given event, the more likely it is judged that the event will occur. Things that happen often are easy to remember. The frequency of reporting the occurrence of an event like a natural hazard will increase its perception. But many other factors also influence recall - mental 'availability' of information - and thus perception of risk. Attributes of drama, context and experience influence recall. Dramatic information rich in death and disaster tends to be highly memorable.
For most people, personal contact with hazards is fairly rare and so knowledge of them is acquired more through the news media than from first-hand experience. The way the media report hazards is extremely influential in risk perception. The media tend to concentrate on the more unusual and dramatic happenings in its reporting, and so these events are often perceived to be more frequent than they actually are.
Research has been carried out in the USA and a number of other industrialized countries into risk perception. Experiments asking various groups of people to judge the frequency of various causes of death, like diseases, accidents and natural hazards, show that judgements are moderately accurate with a number of distinct biases. People tend to know in general which are the most common and least frequent lethal events but there is a general tendency in these fairly well-informed subject groups to over-estimate the incidence of rare causes of death and underestimate the frequency of the more common ones. A summary of one of the tests in Oregon, USA is given in figure 2.8
It has been suggested that these over and under-estimation biases correspond to coverage in the United States media. In the Oregon example accidents are perceived to cause as many deaths as disease, but in reality diseases cause 15 times as many deaths; murder is wrongly attributed to cause more deaths than diabetes, and disaster risks such as floods and tornados are distinctly overestimated. The overestimated risks correspond with favorite newspaper and media topics and it appears that in a society with strong media exposure perception of risk is highly influenced by media treatment.
Research has also shown that frequent reiteration of the fact that certain events (like an aircraft crashing) are rare may have the opposite effect on an audience who may perceive only the fact of the event (the concept of air crashes) and not the message (that they are rare) thus reinforcing the psychological 'availability' of information on air travel risk.
Risk perception with less information
There is evidence that risk perception is considerably influenced by availability of information.
By contrast with the above example of a well-informed group in an affluent society, populations without regular exposure to news media may underestimate the environmental risks they face. There is evidence that risk perception is considerably influenced by availability of information. Some societies without access to information on hazards appear to have lower perceptions of the risk of natural hazards that might strike them. Research with a range of different subject groups has shown that an individual's background and experience - variables like technological familiarity and social grouping - can affect risk perception considerably and quite selectively. There have been no psychological studies of perception of risk among groups much less exposed to media coverage or groups with much higher actual risks of natural disasters comparable with that described above, but a number of social studies of less-informed communities facing high risks have concluded that the individuals are probably more at risk from hazards than they realize.9 Rural communities or societies with little formal education may have less information available to them on which to make risk decisions. Their perception of risk is likely to be shaped more by personal experience, local and recent events and verbal folklore than by media presentation of risks. Information horizons - the distance from which they are brought news and the length of history they have available to them - may not encompass the rarer events that pose their major threat. Their familiarity with hazards - particularly with return periods longer than their lifetimes - may be minimal and causes of hazards and recognition of danger signs may be beyond their experience.
A common ingredient of disaster mitigation programs is a public education program to increase disaster awareness. This is not only to increase perception of risk where it is judged too low, it is also to educate the public that disasters are preventable and to encourage them to participate in protecting themselves.
Q. Some risks are dealt with on a day to day basis and are considered "acceptable". We consider other risks "unacceptable" and alter our plans significantly in order to avoid them. What factors associated with risks make them seem more "acceptable" to us? Compare your answer with the discussion of qualitative aspects of risk perception on the next page.
Whether or not a particular risk is "acceptable" is largely a question of perception. Factors affecting the perception of hazard risk include:
the horror associated with the hazard (dread)
Qualitative aspects of risk perception
"It'll never happen to me."
An important finding of the research in risk perception is that the abstraction of risk is more easily accepted than the personalization of risk. "It'll never happen to me," is a common attitude in both richer and poorer societies. Complex issues relating to risk and to the possibility of personal injury are handled psychologically by rejecting them. The risk of death or injury to a group of people, even a group that includes the individual is more readily accepted than the risk to the individual personally. Familiar risks confronted many times like driving a car on mountain roads or crossing a dormant volcano may well make this risk discountable, or of lower perception. Inescapable risks may be completely rejected and virtually ignored.
In general, the research into perception shows that people evaluate risks through a number of subjective concepts and beliefs in a multi-dimensional way. The quantitative aspects of risk are less important than some of the qualitative attributes of the risk - the image of a particular risk and the conjecture associated with it. Four factors appear to be important in perception of risk:
Exposure - Actual quantitative risk level
Familiarity - Personal experience of the hazardous events
Preventability - The degree to which the hazard is perceived as controllable or its effects preventable
Dread - The concept of the hazard that some researchers term 'dread' is the horror of the hazard, it's scale and consequences.
It is clear that disasters have a high dread factor, and are widely perceived as unpreventable. Images of disasters maiming, burning and spilling blood evoke higher dread factors than those of suffocation or drowning. Disasters that cause large numbers of deaths are more dreadful than low-fatality catastrophes. Perception of risk appears closely related to the dread factor, and only generally related to exposure levels or to personal familiarity.
It is also clear that increased access to factual information can increase perception of risk and thereby also reduce acceptance of risk and affect what is considered 'safe.'
High levels of perceived risk are usually associated with desires or actions to reduce risk and with support to the community and its representatives to reduce risks on their behalf. It is also clear that increased access to factual information can increase perception of risk and thereby also reduce acceptance of risk and what is considered 'safe.'