RISK PERCEPTION AND COMMUNICATION
This chapter explains how people perceive the risks of environmental hazards and the actions they can take to protect themselves from those hazards. Addressing such perceptions is the most common way for emergency managers to change the behavior of those at risk from long-term threats or imminent impacts of disasters. This chapter describes the Protective Action Decision Model, which summarizes findings from studies of household response to disasters, and concludes with recommendations for risk communication during the continuing hazard phase, escalating crises, and emergency response.
Risk can be defined broadly as a condition in which there is a possibility that persons or property could experience adverse consequences. Some people, by virtue of their access to data or their specialized expertise in interpreting those data, have more information than others about the risk of a particular hazard and about ways in which that risk can be managed. These risk analysts have a responsibility to convey their assessments to decisionmakers who must determine what action to take in response to the risk that the analyst has characterized. These assessments typically define risk in terms of the likelihood that an event of a given magnitude will occur at a given location within a given time period and describe the expected consequences that the event will inflict on persons, property, and social functioning. The decisionmakers to whom the analysts communicate this information can be either the population at risk or emergency managers who are responsible for protecting the population at risk. In either case, the principal reason for risk communication is to initiate and direct protective action.
Risk communication has become a common concept in recent decades—appearing in many contexts (infectious diseases, food additives, natural hazards, routine effluents, and technological accidents) and referring to many target groups (employees, households, minority groups, and legislators, to name only a few). The principal concern of this chapter will be events that, because of their rapid onset and the large amounts of energy or materials released, have the potential to cause significant numbers of casualties and substantial amounts of property damage unless timely and effective action is taken.
Some of these extreme events originate in the natural environment and, thus, are known as natural hazards. Events involving the release of substantial amounts of energy (e.g., earthquakes) can cause immediate destruction of buildings and infrastructure, inflicting many casualties (deaths, injuries, and illnesses) and much disruption to social, economic, and political activities. In some cases, these effects are immediate, whereas in other cases they might take years to manifest themselves.
In addition to hazards originating in the natural environment, there are also hazards that are transmitted through the natural environment. These include some, but not all, of what are commonly referred to as technological hazards. Some technological hazards can have a very rapid onset and have the potential for killing many people very quickly unless there is a prompt and effective emergency response. Others involve the cumulative effect of routine air- or water-borne releases from technological facilities or contamination of food and drugs. Many exposures to these hazards unfold over an extended period of time and the adverse health effects even more delayed—frequently producing low incidence rates of disease in the affected population. Regardless of the speed of onset or the persistence of the hazard, the same principles of risk communication are likely to apply.
There is, however, a temporal distinction that is central to the organization of this chapter—the amount of time between the detection of the hazard and the onset of exposure. A risk communication effort addressing the imminent threat of an extreme event is referred to as a warning; it is intended to produce an appropriate emergency response. By contrast, a risk communication program addressing the long-term potential for such events to occur is often known as a hazard awareness program; such efforts are intended to produce long-term hazard adjustments. There are quite distinct research literatures on natural and technological hazards that have produced similar conclusions about warnings but have encountered an important difference in the case of hazard awareness programs. Natural hazards seem to arouse substantially less concern than technological hazards, so risk communication programs about the long-term threat of natural hazards generally have sought to increase public concern. By contrast, risk communication programs about the long-term threat of technological hazards have more frequently sought to decrease public concern. Research on technological risk perception has sought to explain why some hazards elicit more concern than others, and it appears the difference is due, at least in part, to such hazard characteristics as the voluntariness and controllability of hazard exposure and the degree of dread about its consequences (Slovic, 1987).
Risk communication attempts to promote appropriate protective behavior by those to whom the information is directed; such hazard adjustments to long-term threats include modifying the hazard, modifying the hazard’s impact by preventing specific effects, moving to another location, changing the land use to reduce hazard vulnerability, sharing the loss, or bearing the loss (Burton, et al., 1993). Alternatively, one can think of such behavior changes as disaster responses to an imminent threat by such actions as evacuating, sheltering in-place, expedient respiratory protection, or food interdiction (Drabek, 1986; Mileti, Drabek & Haas, 1975).
In general, this chapter will emphasize the communication of information to those who are actually at risk of exposure to a hazard, but also will recognize the need for communicating to those who think they are at risk of exposure to the hazard even if authorities do not share this belief. In the latter case, messages are sometimes needed to convince people they do not need to take protective actions because they will not be exposed to the hazard or because the actions being taken by authorities will be sufficient to protect them. Alternatively, such messages might be designed to convince people that hazard managers do not need to implement protective actions because the costs of responding outweigh the risk. Moreover, authorities are occasionally knowledgeable enough about citizens’ concerns that a one-way communication flow from them to citizens will produce results that are satisfactory to all concerned. In practice, however, authorities frequently need feedback from citizens and should expect such feedback whether or not they believe it is needed. For most environmental hazards, the risk communication process should be based upon a hazard analysis that identifies risk areas—the geographical locations in which the environmental extremes are expected to occur—and the mechanisms by which exposure can occur. The risk communication process also should be guided by a vulnerability analysis identifying the populations and property located in those risk areas. These analyses provide the basic data upon which messages can be formulated that describe the vulnerability of different population segments and the protective responses that are appropriate to reduce these risks.
It is important to recognize that one cannot focus exclusively on a risk analyst’s definition of the situation to generate risk messages. Unfortunately, many well-intended attempts at risk communication are based on the assumption that risk area populations fail to implement analysts’ protective action recommendations because they are unaware of or misperceive the risk. Thus, analysts assume that disseminating scientific information about the hazard agent will motivate people to adopt their protective action recommendations. This assumption is correct in some cases, but it substantially oversimplifies the risk communication process because it ignores the roles of the information source, the channel by which the information is transmitted, and the individual differences among message receivers. In addition, this naive approach to risk communication also ignores the effects of impediments to information processing such as competing demands for attention, the use of cognitive heuristics (simplified rules of thumb for processing complex information), and conflicts of the new information with people’s existing beliefs (Yates, 1990). Finally, such an approach neglects the social structural (community) and cultural environments in which communication processes are immersed (Gudykunst, 1998).
Instead, risk communication should be a process in which stakeholders share information about hazards affecting a community. The use of the term sharing is important because risk analysts and emergency managers must understand how different segments of the population at risk think about a hazard if they are to be effective in communicating with their audience. These population segments include businesses and households that are vulnerable to a specific hazard, as well as community and industry personnel who are responsible for managing a hazard in ways that reduce the risk to a level that is acceptable to the community.
People’s attentiveness to risk communication varies across the four emergency management functions—hazard mitigation, emergency preparedness, emergency response, and disaster recovery. Decades ago, Fritz (1968) observed most of the money and resources for emergency management are expended in connection with response and recovery activities. This is consistent with the cycle, noted in previous chapters, of significant citizen and government interest in disasters only during imminent threats and in the immediate aftermath of disasters. However, public attention declines significantly as time passes. Because considerable time is required to translate public concern into government budget allocations and coherent programs, many mitigation and preparedness programs have simply failed to be implemented (Birkland, 1997; Prater & Lindell, 2000).
The important differences between imminent threat associated with response and recovery and the long-term threat associated with mitigation and preparedness—especially the significant differences in the behavior risk communicators should expect from those at risk—suggests there should be corresponding differences in the risk communication processes associated with these two different types of situations. This dichotomy between imminent and long-term threats does not imply that two completely different theories are needed to guide risk communication. In fact, most of the same theoretical principles are relevant to both situations, so a single theoretical model can account for short-term warning response and long-term hazard adjustment. Nonetheless, each of these situations requires specific modifications of the overall model.
The Classical Persuasion Model
According to Lasswell (1948), all communication should be analyzed in terms of who (Source) says what (Message), via what medium (Channel), to whom (Receiver), and directed at what kind of change (Effect). This classical persuasion model, which is depicted in Figure 4-1, was further articulated by Hovland, Janis and Kelley (1953) and has remained the predominant conceptual approach in the field of communication, and especially research on persuasive communication (McGuire, 1969, 1985; O’Keefe, 1990).
Research guided by this model has found sources are perceived primarily in terms of expertise and trustworthiness, but also by other characteristics such as status, likeability, and attractiveness. Similar to French and Raven’s (1959; Raven, 1964) definitions of expert and information power, a source’s expertise is defined by its information about a situation and knowledge about cause-and-effect relationships in the environment. By contrast, trustworthiness refers to a source’s willingness and ability to provide accurate information and take actions that protect the receiver without seeking hidden advantage for him- or herself.
Figure 4-1. The Classical Persuasion Model.
Source: Lindell & Perry (2004).
Messages vary in their content—especially their information about a hazard, its impact characteristics (e.g., magnitude, location, and time of impact), potential personal consequences (e.g., likelihood of casualties, property damage, and social disruption), alternative protective actions (e.g., evacuation, sheltering in-place), and the attributes of those protective actions (e.g., efficacy; safety; cost; and requirements for time and effort, knowledge and skill, tools and equipment, and cooperation from others). In addition, messages also vary in terms of their style (clarity, forcefulness, and speed of delivery, use of figurative or humorous language), inclusions and omissions (whether or not to include one’s own weak arguments, address opponents’ arguments, or to rely on implicit or explicit conclusions), ordering of message content, and amount of message material (McGuire, 1985).
The information channels available for use by emergency managers include print media such as newspapers, magazines, and brochures; electronic media such as television, radio, telephone, and the Internet; and face-to-face interaction through personal conversations and public meetings. The distinctions among these information channels are important because they differ in the ways they accommodate the information processing activities of receivers. For example, orally presented information is ephemeral and will be lost unless otherwise recorded, whereas written information inherently provides a record that can be examined at a later time. Moreover, many types of risk information can be presented in either verbal (words), numeric (numbers), or graphic (pictures) format. Sometimes one mode of presentation is more effective for a particular type of information; for example, charts generally are more effective than tables of numbers in conveying trends. However, there are individual differences among receivers, so some presentation modes are more effective for some people but not others. For example, some people can understand verbal descriptions much more readily than graphs of data, whereas the reverse is true for others.
Receivers differ in many respects, but the most important of these are psychological characteristics that have direct effects on the communication process. For example, receivers differ in their perceptions of source credibility, access to communication channels, prior beliefs about hazards and protective actions, ability to understand and remember message content, and access to resources needed to implement protective action (Lindell & Perry, 2004). The effects of a message on a receiver include attention, comprehension, acceptance, retention, and behavioral change. Indeed, researchers agree message effects should be characterized in terms of multiple stages, but the boundaries among these stages are not well defined, so differences exist among various researchers in their typologies (see McGuire, 1985 vs. Mileti & Peek, 2001) and some theorists have varied in their definitions of these stages over time (McGuire, 1969, 1985).
Finally, feedback is an important component of the communication model because some attempts are unidirectional, whereas others are interactive. Unidirectional communications are appealing to many risk communicators because they appear to be less time consuming and sometimes this actually is the case. Frequently, however, interactive communication is needed for receivers to indicate they have not comprehended the message that was sent or to explain that the message sent by the source did not satisfy their information needs.
The classical persuasion model makes it clear that risk communication is an activity with relatively clearly defined parameters regarding source, message, channel, and intended effect. In most cases, the source is an authority, the message describes an environmental hazard, and the intended effect is a change in receivers’ behavior. However, receiver characteristics have very important influences on each of the stages in the communication process. For example, the effect of a given information source is determined by receivers’ perceptions of that source and the effect of a given message is determined by receivers’ willingness to attend to and ability to comprehend and retain the information. Moreover the effect of a given channel is determined by receivers’ access to and preference for that channel and the amount of feedback depends upon receivers’ willingness and ability to provide it. Unfortunately, authorities often fail to recognize the importance of these factors and sometimes fail to design risk communication programs in accordance with the principles of effective communication even when these issues are recognized (Perry & Lindell, 1991).
Some scholars have criticized the classical persuasion model as providing an incomplete representation of the risk communication process (Kasperson & Stallen, 1990). They contend the feedback loop in the model implies a dyadic relationship that is limited to contact with the original information source. However, extensive research shows people engage in information seeking activities that are directed to other sources as well. More generally, risk communication should be represented by a network in which multiple sources are linked to intermediate sources who receive information and relay it to the ultimate receivers (Figure 4-2). The original sources could be linked to few or many intermediates or could even be linked directly with some of the ultimate receivers. Similarly, the intermediates could be linked to few or many of the ultimate receivers and the ultimate receivers could be linked to each other.
Another apparent limitation of the classical persuasion model is that receiver characteristics have pervasive effects on the other components of the model. For example, receivers’ demographic characteristics are correlated with access to sources and channels, as well as with message comprehension. Thus, receiver characteristics are of critical importance in determining the success of risk communication programs, but many of them are psychological in nature and, thus, not readily observed. Nonetheless, receivers’ demographic characteristics—such as sex, age, education, income, race, and ethnicity—are readily identifiable. Because some of these demographic characteristics are related to relevant psychological characteristics, they can provide some indication as to how receivers will respond.
The Protective Action Decision Model
A review of theories on social influence, persuasion, behavioral decisionmaking, attitude-behavior relationships, protective action, and innovation processes reveals a wide variety of perspectives providing useful accounts of the ways in which risk communication can influence disaster response and hazard adjustment (Lindell & Perry, 2004). Although these theories overlap to some extent with the findings of research on hazards and disasters, all of them provide valuable insights that can extend our understanding of ways in which people respond to the threat of environmental hazards. The relevant elements of these complementary approaches have been integrated with the findings of disaster research to produce a model of the factors that influence individual’s adoption of protective actions against natural and technological hazards and disasters. This integrated model is the Protective Action Decision Model (PADM).
Figure 4-2. Communication Network Model.
Source: Lindell & Perry (2004).
According to Lindell and Perry (2004), the PADM is most directly based upon a long history of research on disasters that has been summarized by many authors (Barton, 1969; Drabek, 1986; Fritz 1961; Janis & Mann, 1977; Lindell & Perry, 1992; Mileti, et al., 1975; Mileti & Peek, 2001; Mileti & Sorensen, 1987; Perry,et al., 1981; Tierney, et al., 2001). This research has found sensory cues from the physical environment (especially sights and sounds, see Gruntfest, Downing & White, 1978) or socially transmitted information (e.g., disaster warnings) can each elicit a perception of threat that diverts the recipient’s attention from normal activities. Depending upon the perceived characteristics of the threat, those at risk will either resume normal activities, seek additional information, pursue problem focused actions to protect persons and property, or engage in emotion focused actions to reduce their immediate psychological distress. Which way an individual chooses to respond to the threat depends upon evaluations of both the threat and the available protective actions.
The findings of previous disaster research can be combined with propositions drawn from the theories listed earlier in this chapter to express the PADM in terms of a flow chart that provides a graphic representation of the model (see Figure 4-3). The process of decisionmaking begins with environmental cues or risk communication messages that initiate a series of predecisional processes. In turn, these predecisional processes stimulate either a protective action decisionmaking process or an information seeking process. To proceed through the successive stages of either process, the individual must arrive at an affirmative answer to the questions posed. The dominant tendency is for environmental cues and risk communication messages to prompt protective action decisionmaking, but information seeking occurs when there is uncertainty about the answer to the critical question at a given stage in the protective action decisionmaking process. Once the question is resolved, processing proceeds to the next stage in the protective action decisionmaking process.
Figure 4-3. Information Flow in the PADM.