Risk Perception in Community Context.
Evaluating the psychometric paradigm and its relationship
to risk amplification and reported communication channel usefulness.
A paper presented to the Science Interest Group at the
Annual Meeting of the Association for Education in Journalism and Mass
by Craig W. Trumbo
Department of Agricultural Journalism
440 Henry Mall
The University of Wisconsin
Madison, WI 53706
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This project incorporates three sequential steps. First, the
psychometric model of risk perception is evaluated for its validity
under field conditions. Second, individuals are classified as
or attenuators within the social amplification of risk model.
the characteristics of attenuators and amplifiers are explored, with
special focus on their use of communication channels. Survey data from
an on-going case study is employed in the analysis. The case study
involves a mid-western community in which a controversy exists over the
possibility of the existence of a cancer cluster caused by the
of a small reactor.
Results show that the psychometric model of risk perception has validity
under the field conditions utilized in this study. Use of the
psychometric model to classify individuals as risk amplifiers or risk
attenuators produces a useful dichotomy that reveals differences
the two polar groups in terms of demographics, satisfaction with
institutional response to the risk, concern over individual and social
levels of risk, and the evaluation of various communication channels
having been useful in coming to a judgment about the risk.
A final model comparing the two groups suggests that, in this case, two
dominant forces are in play against one another: an evaluation
personal risk versus satisfaction with the institution managing the
risk. Subordinate to these forces are the demographically based
variables of education and years of residence in the community. This
model also illustrates that aggregate-level observations may not be
fully characteristic of underlying processes of polarization.
The author would like to thank the following individuals for their
insightful comments on this project: Garrett O'Keefe, Sharon
and Jack McLeod.
Risk has recently grown as a topic of interest within the field of
communication, with two related problems generally of greatest
The first involves the nature and consequences of news media
representation of risk, typically with respect to technological or
environmental controversies. The second area involves the difficulties
encountered by scientists and other experts charged with informing
lay public about their risk from various natural or man-made
The second area has most involved communication researchers in the
of risk perception: understanding how the individual perceives and
judgments about risks faced in life.
This investigation has the overarching goal of advancing understanding
of how individuals come to a judgment about risk. This goal
focus on the role of communication channels within the process of
This project incorporates three sequential steps. First, the
psychometric model of risk perception is evaluated for its validity
under field conditions. Second, individuals are classified as
or attenuators within the social amplification of risk model.
the characteristics of attenuators and amplifiers are explored, with
special focus on their use of communication channels. These areas of
literature will be addressed following a description of the case
being utilized in this project.
2. CONTEXT: THE CASE STUDY
Since the Manhattan Project, the U.S. Department of Energy has operated
its Ames Laboratory at Iowa State University in Ames, Iowa. The
assignment of the Ames Lab was to purify enriched uranium for use in
atomic bomb program. Since then the Ames Lab has continued to be
involved in ceramics and metals development, methods of non-destructive
analysis, and the development of environmental remediation
Ames Lab is also very active in the area of technology transfer.
Over the years, various activities and accidents at the Ames Lab have
created a handful of waste sites in the Ames area. The Ames Lab
citizens of Ames have recently been in conflict over three such
situations. The first involves the construction of a youth sports
complex on a site contaminated in 1953 by low-level radioactive thorium.
Despite being cleaned-up in 1988, community resistance stalled the
city's plans to build there. The second issue involves the clean-up
waste burial site in Ames where some 7,000 pounds of low level
radioactive and other mildly hazardous materials have been interred for
about 40 years. The DOE has recently concluded the remediation of
The third issue involves a small research reactor that the Ames Lab and
Iowa State University jointly operated from 1965 until
in 1981. Some residents of the Ross Road neighborhood (one-half mile
directly south from the former reactor site) believe that they are now
part of a cancer cluster caused by the reactor. One section of the
neighborhood had 13 cases. Two epidemiological studies have been done.
The first was inconclusive and the second found that cancer rates in
area were not significantly above normal.
To address concerns in the community, the Ames Lab has hosted four
public forums, a community workshop, and has created an information
repository on reserve at the ISU library. These issues have also
received a fair amount of attention from the local newspaper.
This investigation has as its primary focus the third issue: the
perceived cancer cluster. This issue is being emphasized for two main
reasons. First, it is of an enduring nature. It predates the other
issues and will out-last them as well. Second, it is an intractable
problem: there is no evidence of a cancer cluster D and even if there
was such evidence it could not be causally associated with the former
reactor. While the cancer cluster issue cannot be termed a "hot
topic, it is a issue that is widely known of in the community. The
aspect is that due to the general recognition of the issue most
individuals have had to come to some conclusion about it.
In more general terms, the situation faced by Ames residents is not
uncommon. Many communities face relatively small and localized
issues. Cases like Love Canal or Times Beach capture high media
attention, but are atypical of the experience Americans more commonly
have with environmental hazards. Understanding how individuals
their situation relative to this variety of hazard and how they use
information channels to form opinions is a task of some importance.
To frame the primary questions of this investigation, three areas of
literature will be briefly examined: the psychometric model of
perception, the social amplification of risk model, and communication
The Psychometric Model. A considerable amount of research has been done in
the area of risk perception. Dunwoody and Neuwirth prefer the
judgment" to emphasize the active information processing inherent in
construct. In any case, the psychometric model of risk perception
grown from research that asks individuals to compare a range of
based on a set of attributes, such as how well the hazard is
or how many people might be affected by the hazard. The research has
consistently shown that people evaluate hazards not only on the
objective harm (e.g., deaths per year) but also on a range of more
The series of projects initiated by Fischoff and coworkers, and carried
on by Slovic and associates, have shown that two important
can be seen to describe the perception of risk.  One dimension
is termed dread. This is related to the scale of the risk and the
to which it impacts innocent individuals. The second dimension,
knowledge, involves how well a risk is understood and how observable
The model has since been widely replicated and cited. The risk space
model has been validated in various countries and researchers have
expanded risk into additional dimensions using a wide variety of
attributes such as the number of people affected or the voluntariness of
the risk.   Non-human mortality and transgenerational effects
been examined as risk perception factors. But the basic premise
two dimensional psychometric risk perception model has remained
Some salient criticisms of the model have been addressed, including
consistency among individuals in risk perception and the nature of
perception within a single technological domain. The model held
these investigations, and also faired well in a reanalysis of the
original data carried out by Gregory and Mendelsohn, who also found that
perceived benefit plays a role in risk perception.
While these studies do suggest a remarkable validity to the psychometric
model, an important weakness remains in this direction of
risks are examined in the abstract. People can certainly be called upon
to evaluate a set of risks, or attributes of a single risk, even
they do not personally face that risk as an important aspect of
life. But is it safe to assume that people perceive or judge risk in
same way when it involves a "live risk," a hazard or a risk
that is part of daily life?
This question is not ignored in the literature. Risk perception studies
have looked at specific risks in context. Such research has
been in the form of case studies. While these studies and others
great merit, they have not employed the psychometric risk perception
model. It would be useful to know if the psychometric model can be
to understand the perception of such local hazards. That is the
issue to be addressed in this study.
Social Amplification of Risk. In response to the acute need to find some way
to bring the diverse array of perspectives on risk, risk
risk communication together into an integrative framework, Kasperson
coworkers formulated the social amplification of risk.
Social amplification of risk holds that the communication and behavioral
responses of individuals, groups, and institutions operating
risk event or controversy act as "amplification stations." It is the
interaction among the risk interpretations and responses of these
stations that determine the nature of the life course, or "rippling," of
the risk event or controversy.
Within the concept of the amplification station exists a linkage between
the macro level social functions of institutions or groups and
level processes that operate within and between individuals.
conceptualizes the micro level functioning as "individual stations
amplification" and the macro level analog as the "social stations of
Social amplification is primarily a framework in which to utilize a
variety of discrete theories and methods. Renn describes how
amplification might integrate the strengths and weaknesses of the
social, psychological, and cultural approaches to risk. The
problems of each approach D social relevance for psychometrics,
complexity for sociology, and empirical validity for cultural theory D
may tend to cancel out and allow for an emergent perspective.
The full application of the social amplification framework is a complex
and long-term research goal. The present investigation has a
specific focus: to develop an understanding of how individuals can be
classified as being either amplifiers or attenuators within the
of the individual station of amplification. The existence of this
dichotomy is a key micro-level prediction of the social amplification of
Since no objectively-based definition of risk exists in this case study
it must be held that amplifiers and attenuators exist relative
other by way of their perception of risk from the threat D as
existing relative to some "true" condition. In other words, there is
"correct" position in this controversy. Within this framework, the
evaluation of individuals' perception of risk might be based on the
psychometric model and this evaluation may in turn be used to group
individuals as either amplifiers or attenuators.
While largely a semantic matter, placing amplifiers and attenuators
under the umbrella of amplification (in its engineering guise as to
either increase or decrease) can create unnecessary confusion. Rather,
the idea will be recast as what it essentially is: polarization.
Channel Utility. The final aspect of this study seeks to examine the
information channels people use in forming an opinion about a
risk. The focus of concern will be the relative roles of mass
communication, interpersonal communication, and other forms of informa
Chaffee presents an argument that the dichotomy of mass versus
interpersonal communication has been endowed with excessive
His analysis of the literature builds the case that individuals use a
given channel based on how accessible the channel is and how likely
individual believes it is that the desired information will be found
a particular channel. In this light, it should be emphasized that
research does not seek to determine mass or interpersonal supremacy,
rather to assess the various ways in which individuals use both
in coping with a specific risk situation and how these channels
to other forms of information-seeking.
A handful of studies inform this question. Mazur and Hall examine how
members of a New York county evaluate the risk of radon as either
specific concern in the home or as a more diffuse national hazard.
find that neither interpersonal contact with family members nor mass
media messages correlate with a specific concern about radon in the
home. However, both were strongly correlated with a more general
about radon as a national hazard, with family influence considerably
stronger than mass media influence.
McCallum and coworkers compared mass media and interpersonal channels as
preferred ways of gathering information about toxic chemicals in
local environment. They surveyed subjects in six communities around
nation that were facing toxic chemical issues and found that mass
channels were strongly preferred as sources of such information.
Interpersonal sources were used only 12% of the time.
Following Tyler and Cook's observation that mass media impact
social-level judgments more than individual-level judgments, Coleman
found that mass media are stronger than interpersonal channels in
influencing society-level risk judgments. Mass media also had some
influence on personal risk judgments, an effect which interpersonal
channels did not have.
Contrasting the variety of findings in these studies goes to Chaffee's
argument: interpersonal and mass communication channels have
roles in shaping people's perceptions and no broad generalization can
hold. The role of other information-seeking behavior is less clear
these studies. Chaffee points out that people have varying abilities
use other information resources, such as libraries or expert
Dunwoody and Neuwirth also point out that people probably make
use of various channels during the life span of their relationship
a given risk. This study will attempt to address these issues,
at the relative usefulness of mass communication, interpersonal
communication, and other forms of information-seeking in the process of
4. RESEARCH QUESTIONS
This study is both confirmatory and exploratory in nature. It seeks to
confirm that the psychometric model describes how individuals in
case study evaluate the given risk. It also seeks to confirm that the
individuals engaged in this risk controversy can be productively seen
being polarized into amplifiers and attenuators. Finally, it seeks
explore the characteristics of polarization and look for important
differences between the two camps. Toward these ends, this study employs
a set of three research questions:
RQ1: Do individuals evaluate the given risk in terms of dread and
knowledge as the psychometric model predicts?
RQ2: Based on the psychometric model, can individuals be consistently
grouped as amplifiers and attenuators as polarization predicts?
RQ3: What differences are there between attenuators and amplifiers in
terms of the demographic, risk, and channel use variables
A mail survey instrument was developed to achieve the goals of this
investigation. The instrument consists of three general segments.
the set of original psychometric model questions were modified
to fit the specific issue at hand. While researchers have expanded
modified this set of questions, the model is most strongly
with nine aspects of dread and five aspects of knowledge. These
questions are shown in Table 1. The second part of the instrument
consists of a set of questions seeking to ascertain what sources of
information people have found to be useful in making judgments about
this risk issue. Questions are also asked concerning satisfaction with
attention paid to this issue by local media, Ames Lab officials,
government representatives and others. Finally, a few general
demographic variables are included.
The sampling unit is the non-rental household. Subjects are drawn from
the northwest quadrant of Ames D the area defined by previous
epidemiological studies and by stories in the Ames Daily Tribune . The
area is also defined by social and geographic boundaries: the city
limits to the north and west, and a large park to the south and east.
The current Polk's City Directory for Ames was consulted as a
frame. A random sample of 50% identified 223 households to
in the survey. Either principal adult member of the household could
complete the questionnaire.
Mail survey procedures described by Dillman were adhered to and the
survey arrived in Ames on about September 23, 1994. The survey
period was closed on November 1, 1994. At that time, 130
were received for a return rate of 58 percent.
6. DISCUSSION OF THE RESULTS
The first task is to evaluate the psychometric model and determine if it
can be used as an effective means of proceeding with the
14 questions shown in Table I were entered into a factor analysis.
rotated factor matrix was virtually uninterpretable. The results
presented one strong factor with a mix of knowledge and dread variables
and several weak factors with one or two variables each. No clear
pattern was discernible.
The further evaluate the model, the communalities of the variables were
examined to see if there were any very weakly associated
might be appropriately excluded from the analysis (overall, the KMO
statistic was adequate at .75). All variables but one had strong
communality: the dread variable FATAL describing the likelihood that any
illness from the risk would be fatal. This single weak variable was
ejected and the factor analysis was again executed. Table II presents
the results. With the exclusion of the one weak variable the rotated
matrix provides a satisfying solution that conforms well to the
prediction of the model.
One knowledge factor emerges made up of individual and scientific
knowledge about the risk, how familiar the risk is to the individual,
and how observable the consequences of the risk are to the
Dread appears to be made up of 2 components. Factor 2 might be
"pure dread" as it consists of elements that relate more clearly to
fear: catastrophe, transgenerational effects, an increase in the risk,
and being unable to calmly contemplate the risk. Factor 3 appears
closely related to the idea of personal efficacy. This factor
the individual's ability to control exposure to the risk, ability to
exercise choice in accepting the risk, and personal ability to reduce
the risk. These all speak to the degree of individual agency with
ct to the risk. A fourth uninterpretable factor emerged that has an
equal measure of both knowledge and dread.
Overall, the solution to the factor analysis supports the application of
the psychometric model in this field situation, satisfying the
research question. This is a fairly important result in itself since
psychometric model has been most frequently applied to the
individual perception of a range of risks considered in the
This analysis suggests, at least for the specific risk examined in
case, that individuals may indeed evaluate risks they face through
processes that can be understood in terms of knowledge and dread.
The four factor solution approaches but does not completely satisfy the
proposition of a two-dimensional model of risk perception.
remain: how do the four factors relate to one another, are the two
factors associated, and how should the fourth uninterpreted factor
treated? To resolve these questions, factor scores were treated in a
second-order factor analysis. The resulting two factor solution
the dread factors together and grouped the knowledge factor with the
fourth uninterpreted factor. With this result taken as evidence of
association, variables for the dimensions of dread and knowledge are
created by averaging the associated factor scores. Both variables are
approximately normal with mean of 0 and are uncorrelated.
The second research question asks if the psychometric model might be
applied to the task of separating individuals into amplifiers and
attenuators. The literature on the recent concept of social
amplification does not suggest what characteristics might indicate the
two groups. To define the groups, the variables dread and knowledge
plotted against each other and the scatter is divided at the mean
created by the line with slope -1 running through the origin of the
A discriminant analysis was run to confirm that this method of group
determination is in fact consistent with the nature of the
variables being used. The classification analysis used the full set of
13 variables to predict the polarization groups. The classification
matrix shows strong agreement that the 13 variables can identify two
groups divided along mean responses to dread and knowledge. The
correctly classifies 100% of the cases, identifying 54 amplifiers
attenuators (some cases are lost due to incomplete responses). No
significant differences were found between this group of 94 and the 36
other survey respondents.
Research question three asks what differences might exist between the
two polarization groups. Table III provides the significant
which can be organized in blocks: demographics, risk perception and
behavior, satisfaction with institutional response to the issue, and
reported usefulness of various information channels.
Two of the demographic variables show a significant difference between
attenuators and amplifiers. Both gender and education are
related to polarization. While amplifiers are slightly more likely
female, attenuators are very much more likely to be male (overall,
respondents are 47 percent female). Attenuators also have typically
completed more education, with over half having completed a graduate
degree (recall that Ames is a college town). As these results suggest,
further crosstabulation confirms that gender and education are
significantly related with males having more education. The respondent's
age is independent of group status.
Two other demographic variables approach significance and are worth
discussion. It was suspected that the presence of cancer in the
respondent's family might tend to be related to amplification. The data
show this association, but only at a weak level of significance (p =
.11). Length of residence in the area is also of interest since the
reactor was removed in 1981. The data again provide weak evidence for
this association (p = .098). Amplifiers tend to be newer to the area,
with a mean length of residence of 15 years as opposed to 20 years
attenuators. It may very well be a coincidence that the reactor was
removed 14 years ago. Nonetheless, amplification may be intertwined
a fear of the unknown, as some of these individuals have never
seen the former facility. It is also likely that generational
differences may exist between the two groups with respect to
environmental values and trust in government, for example
Risk perception and behavior variables provide a number of significant
differences between the two groups. Taken together, these items
roughly conceptualized as worry. Most of these differences would be
expected by virtue of the method of differentiating the groups. As
they also provide additional support for the validity of the two
Amplifiers think about and talk about the cancer cluster issue more
frequently than attenuators and also feel that both they and others are
at greater risk. These differences are quite pronounced. On the
hand, there were no significant differences found when asking how
an individual had been aware of the issue or when asking what
individual might have taken because of concern over the issue.
attenuators are no different from amplifiers when it comes to
other individuals in the area who have cancer.
The set of four satisfaction variables were all predictably different.
Attenuators are uniformly more satisfied with attention paid to
issue by Ames Lab, by elected officials, and by the news media. They
also more satisfied with the results of the existing epidemiology.
The channel usefulness variables provide rather dramatic results in
terms of non-significance. Of the 10 sources of
information evaluated as having been useful in making a judgment about
personal risk, only neighbors reveal a significant difference
the two groups. Usefulness of family members differs between the
but only weakly (p = .076). Amplifiers rated both neighbors and
members as being more useful sources of information. The 8
sources that showed no difference between the groups were the
television, friends, physician, elected officials, Ames Lab
public meetings, and the library's information repository.
Ranking of the usefulness of information channels is different for the
two groups. An examination of the means of the 10 source
variables shows that both groups rated the newspaper as the most useful
source of information. After that, the rankings diverge. Amplifiers'
five are newspaper, neighbors, television, friends, and family.
Attenuators' top 5 are newspaper, television, friends, neighbors and
Ames Lab officials. Spearman's rho between the two rankings of 10
is only .11 (not significant). This lack of association in the two
groups provides evidence that the two groups are utilizing information
For the next step in the analysis, all of the variables found to be
significant (at p < .1) in detecting group differences were
into a discriminant analysis. Table IV presents the results. The
discriminant function produced by the 13 variables performed well,
significantly accounting for about 40 percent of variance. Correlations
between the individual discriminating variables and the discriminant
function can be interpreted as an indication of the relative strength
the variable's contribution to discriminating the groups. Further,
grouping variables by the sign of the correlation can be useful (note
that all variables are analyzed simultaneously and contribute to case
assignment to both groups).
Variables are sorted by sign and listed by size of the correlation. It
can be seen that evaluation of personal risk, risk to others,
of thinking and talking about the issue, and the usefulness of
and family are grouped together. Conversely the grouping of positive
correlations include education, gender, years of residence, and what
might be taken as a set of variables indicating satisfaction with the
institutional response to the issue.
The sign of the correlation can sometimes be interpreted as indicating
which group it is more closely associated with. In this case,
were assigned the lower value so the set of negative correlations
associated with amplification. Such interpretation must be approached
cautiously. Here, it appears that a lack of the qualities indicated
the negatively correlated variables indicate amplification and a
the qualities indicated by the positively correlated values indicate
The more important results of this analysis are the manner in which the
variables group and their ability to predict group membership.
the variables found to significantly differentiate between the
were in good agreement with the creation of the groups based on the
psychometric model, with a classification rate from the discriminant
analysis of 85%.
Finally, it is important to recognize that attenuators and amplifiers do
not represent two homogeneous groups. There is a distribution of
perception within each group. To recognize this while still pressing
examine for differences between the two groups, a continuous measure
risk perception was created by averaging the dread and knowledge
factors. This scale is then used as the dependent variable in
hierarchical regressions utilizing the 13 variables which show
significant differences between the groups. Variables are analyzed in
blocks representing demographics, interpersonal sources, satisfaction
with institutions, and worry. Results are presented in Table V.
For the analysis of the full sample, each block increments R2
significantly (demographics only at p = .06). The full model achieves an
adjusted R2 of .52 with 5 variables displaying significant partial
coefficients: education, usefulness of neighbors, satisfaction with Ames
Lab, and evaluation of both personal risk and other's risk.
The more interesting results come from a comparison of the two polar
groups. For the attenuators, only the block representing
with institutions significantly changed R2. The primary variable in
column is satisfaction with Ames Lab. It appears possible that an
interaction between gender and education prevents the demographic block
from achieving significance. Inclusion of an interaction term did
alter either the change in R2 or the adjusted R2 for any of the
For amplifiers, the only significant block was the one involving the
worry variables, although the years of residence variable in the
demographic block is itself significant. For the worry block, evaluation
of personal risk is the one strong element.
Stepwise regressions both focus and confirm the significant predictors
of risk perception in the three groups, providing the following
(alpha = .05, showing standardized betas):
Risk = -2.5 + .48 (Personal Risk) + .27 (Other's Risk) - .16 (Education).
Adj R2 = .54 p < .001
Risk = - 0.5 - .57 (Satisfaction Ames Lab) + .36 (Education). Adj. R2
= .33 p < .001
Risk = -0.1 + .62 (Personal Risk) + .25 (Years Residence). Adj. R2
= .43 p < .001
The analysis presented in this paper is a preliminary investigation in
what will eventually be a larger case study. The primary mission
preliminary investigation is three-fold: to gather initial general
information about the population and the controversy, to test the
usefulness of the psychometric model, and to evaluate the viability of
the polarization supposition made by the social amplification model.
results of the analysis to this point suggest that each of these
have been met.
The secondary mission of this preliminary investigation conforms to the
overarching goal of the larger case study: to understand the
communication in risk controversies and to add to the understanding of
effective risk communication. Framing these goals in terms of risk
polarization is not far from stating the problem as one of audience
analysis. Much of the work done to date in risk communication has
treated receivers as a somewhat homogeneous mass D evaluating, for
example, the effectiveness of various forms of message construction
without regard to important differences that might exist in the target
audience. It is likely that risk communication could benefit greatly
shifting some attention from message construction to audience
With respect to the idea of audience analysis, an important lesson is
demonstrated by the hierarchical regression models and their
counterparts: looking at a community's aggregate response to a risk
controversy may be misleading. Different components in the community,
least in this case, have significantly different orientations toward
risk. These differing orientations may be most clearly seen if
conceptualized and measured as polar opposites.
Utilizing such a light to examine the Ames case, it appears that two
dominant forces are in play against one another: an evaluation of
personal risk versus satisfaction with the institution managing the
risk. Conceptually, these forces may approximate the notions of trust
and outrage that have recently come to the risk perception
Subordinate to these forces are the demographically based variables
education and years of residence in the community. Interpreting the
stepwise regression equations for these two subordinate forces further
demonstrates how aggregate characteristics may not be
While attenuators tend to have more education, within their group
greater education is associated with a greater perception of risk. And
while amplifiers tend to have been residents of the area for fewer
years, within their group those who have lived in the area longer
perceive a greater level of risk.
The instrument used in this investigation provides only a rough look at
the communication behaviors of this population. The main purpose
set of questions is to point the way for the construction of a new
instrument to be applied in the near future. There are, however, two
interesting results with respect to communication from the analysis so
First, there is apparently a dynamic involving mediated communication.
Some background on the news coverage is in order. Very little
was paid to this issue by the television stations covering central
Two of the three stations are located in Des Moines, some 40 miles
These stations pay only cursory attention to Ames. The third network
affiliate is located in Ames but has what is widely considered to be
weakest news operation. Attention from the nearest metro daily
newspaper, The Des Moines Register, has been non-existent. The only
significant coverage has been in the local newspaper, The Ames Daily
It is not overly surprising that respondents would rank the local
newspaper as the most useful source of information on the issue. What
interesting, however, is that while attenuators and amplifiers alike
rated the newspaper as the most useful source of information they
differed significantly in their satisfaction with the attention paid to
the issue by the news media overall. This result may suggest that
two groups are processing news information differently.
More refined measures of media use are needed to support this
proposition, but if respondents are basing their satisfaction in part on
how the local newspaper has covered the issue (as opposed to how the
other media outlets have not covered the issue) then amplifiers have
rated the newspaper as most useful but were less satisfied while
attenuators have rated the newspaper as most useful but have been more
satisfied. This suggests the possibility that the same information
the same source had different consequences for different audience
segments. This conclusion is a stretch for these data but not an
The other interesting result from the communication variables is that
the two groups did not differ in their evaluation of the
any of the information channels except for neighbors and to a lesser
degree family members. Since amplification is associated with finding
neighbors and family members more useful as sources of information,
is a fair conclusion to state that concern over risk in this case is
driven by interpersonal communication to a greater degree than by
mediated communication. This finding is in agreement with much of the
research previously cited.
Finally, it is important to return to the notion of polarization, drawn
from the social amplification model, that underlies this
Further investigation of the phenomenon of polarization might proceed
along two lines, utilizing principles of social identification and
models of information processing.
Social psychology has long recognized a process of group polarization.
In the most general terms, this is the process through which a
come to hold and express attitudes that are more extreme than those
individually by its members. There are two dominant theories, social
comparison and persuasive arguments. In social comparison, individuals
compare their own views to the perceived average view held by the
and then tend to shift their attitudes to the more extreme side of
perceived group consensus. The final outcome of a group decision
therefore tends to be polarized. In the persuasive arguments theory,
individuals construct mental lists of arguments for and against a
choice. When individuals discuss these lists in a group that tends to
hold a polarized position, the arguments that are more universally
by group members tend to be those that are more extreme in the
direction. These more extreme arguments then tend to dominate both
individual and group attitudes.
It is likely that some process of this nature has been in play in the
Ames case. The Ames Lab, and its strong association with the
creates an in-group/out-group situation that may have served to
a polarization identity for some individuals. Further, the public
and coverage by the newspaper have likely provided a set of
arguments around which the groups could have formed and strengthened.
Individual polarization has also been related to cognitive consistency.
Chaiken and Yates found support for the hypothesis that
attitude polarization requires the presence of a well-developed
knowledge structure." They found in an experiment that individuals with
a high degree of consistency tended to polarize on an issue more
than their low-consistency counterparts. This point of view
into an information processing perspective offered by Eagly and
in which individuals are hypothesized to process information in
systematic or heuristic manner. Griffin and Dunwoody utilize
perspective to build a model of information processing specifically for
Griffin and Dunwoody consider the heuristic-systematic processing model
and hypothesize on characteristics that might lead individuals
process risk information in one way or the other. They propose a
framework of variables that they organize in categories of demographics,
characteristics of the hazard, individual worry, how individuals
that their information needs are being satisfied, and how confident
individuals feel that they are able to gather needed information. If
there is a relationship among heuristic-systematic processing,
consistency, and polarization D then it is also likely that the
that Griffin and Dunwoody propose could be profitably related to
For the case of the risk controversy in Ames, it might be hypothesized
that amplification is associated with (for example) systematic
information processing of news information intertwined with
interpersonal influence. Conversely, attenuation might be associated
with more rapid "gut level" heuristic information processing of news
information that is intertwined with pre-existing attitude structures
related to trust in the institutions involved. Further research may
approach these questions.
Questions used for risk perception model with codewords.
Dread or knowledge questions indicated with (D) and (K).
For the following questions please give your own personal opinion about possible
to yourself from the former reactor. Circle the number you think
best locates your
position on the 1 to 7 point scale. (low values are for judgments
of low risk)
Catastrophe (D) Do you think this kind of risk - that caused by small nuclear
- has the potential to cause catastrophic death and destruction?
Generations (D) Do you feel that any risk that may be posed from the former
extends to future generations?
Dread (D) Is this the kind of risk you can learn to live with and calmly
about, or one that you constantly dread and worry about?
Changing Risk (D) Do you feel that your risk from the former reactor in Ames is
increasing, decreasing, or staying the same?
Personal Control (D) How much control do you think you personally have over
possible risks to yourself from the former reactor?
Personally Reduce Risk (D) How easy or difficult would it be for you to reduce
risk you might face from the reactor?
Fairness of Risk (D) Do you think the people who may have been exposed to some
from the reactor are the same people who may have benefited from
Fatality of Risk (D) If you were to become ill from this risk, how likely is it
the illness would be fatal?
Personal Choice (D) Do you think you have much choice over accepting any
risks from the former reactor?
Harm Delay (K) Is it more likely that any possible harm to you from the reactor
have occurred immediately after exposure, or that it would be
delayed over time?
Science Knows (K) How knowledgeable do you think scientists are about any
risks from the former reactor?
You Know (K) How knowledgeable do you think you are about any possible risks
Familiarity of Risk (K) Is this a new, novel kind of risk for you, or one
and familiar to you?
Observability of Exposure(K) If you were exposed to a risk from the reactor,
do you think you would be of your risk from that exposure?
Factor Analysis of Psychometric Variables
Factor 1 Factor 2 Factor 3 Factor 4
Variable Mean SD Knowledge Pure Personal Indeterminate
You Know (K) 4.6 2.0 .80
Science Knows (K) 3.4 2.0 .77
Observability of Exposure (K) 4.8 2.1 .56
Familiarity of Risk (K) 4.6 2.3 .51
Catastrophe (D) 2.7 1.8 .80
Generations (D) 4.4 1.9 .69
Changing Risk (D) 2.9 1.4 .61
Dread (D) 2.6 1.8 .59
Personal Control (D) 5.2 2.1 .79
Personal Choice(D) 5.1 2.0 .78
Personally Reduce Risk (D) 4.7 2.1 .62
Harm Delay (K) 5.9 1.6 .75
Fairness of Risk (D) 4.2 2.1 .73
Percentage total variance 32.9 12.1 9.9 8.3
Eigenvalues 4.3 1.6 1.3 1.1
Factors were determined with an eigenvalue cutoff of 1.0, principle components
analysis with varimax
rotation. Loadings under .5 are blanked. Four factors explain 63.2
percent of total variance. KMO
statistic = .75.
Comparison of Amplifiers and Attenuators.
Item Attenuators Amplifiers
mean mean p
Frequency talking about issue (1 never to 6 daily) 1.9 2.3 .004
Frequency thinking about issue (1 never to 6 daily) 2.1 2.9 .002
Risk to others (1 no risk to 7 high) 2.1 4.2 < .001
Risk to self (1 no risk to 7 high) 2.1 4.3 < .001
Usefulness of neighbors in making judgment (0 low to 7 high) 1.1 2.5 .003
Usefulness of family members in making judgment (0 low to 7 high) 0.6 1.3 .076
Satisfaction with epidemiology (1 not to 7 very) 4.5 3.1 .001
Satisfaction with attention from Ames Lab (1 not to 7 very) 4.6 3.1 .001
Satisfaction with attention from elected officials (1 not to 7 very) 3.9 2.4
Satisfaction with attention from news media (1 not to 7 very) 4.5 3.5 .018
Years as resident of northwest Ames 19.5 14.8 .098
Item Attenuators Amplifiers
col % col % c2 p
Respondent's gender 4.5 .03
female 34.2 56.6
male 65.8 43.4
Highest level of education completed 18.5 <.001
high school 16.2 22.6
bachelor's 13.5 50.9
graduate 70.3 26.4
Have any members of immediate family had cancer? 2.6 .11
no 87.5 74.1
yes 12.5 25.9
Evaluation of significant differences between groups.
Saturated discriminant model using variables showing differences between groups
Function 1: Canonical Correlation = .64 Wilks' Lambda = .59 c2 = 37.8
Pooled within-groups correlations between discriminating variables and
.62 Personal risk
.61 Other's risk
.37 Frequency thinking
.35 Frequency talking
.31 Usefulness of neighbors
.22 Usefulness of family
-.42 Satisfaction with representatives
-.39 Satisfaction with news coverage
-.36 Satisfaction with Ames Lab
-.33 Satisfaction with epidemiology
-.18 Years as resident of NW Ames
Risk Perception in Community Context
NO. OF PREDICTED
ACTUAL GROUP CASES 1 2
GROUP 1 44 37 7
AMPLIFY 84.1% 15.9%
GROUP 2 34 5 29
ATTENUATE 14.7% 85.3%
PERCENT OF CASES CORRECTLY CLASSIFIED: 84.6%
Hierarchical Regressions: Risk on Significant Group Differences
Thinking About Risk
Talking About Risk
* p < .10 ** p < .05 *** p < .01
Betas are partial coefficients from regression on each block independently.
Dependnet variable is
risk, as an averaged score of the variables knowledge and dread.
High values on risk equal
perception of great risk.
 Armour, S. (1994, July 7). Uncertainty lingers over sports site. The Am
Tribune, p. A-1.
 Armour, S. (1994, Nov. 26). Meeting p
lanned on waste removal. The Ames Daily
Tribune, p. A-1.
, S. (1994, Jan. 10). Cancer fear lingers in Ames neighborhood. Westside
residents look for answers. The Ames Daily Tribune, p. A-1; Armour, S.
(1994, Jan. 1
U of I researcher begins study of area. Will look at cancer rates in west Ames.
Ames Daily Tribune, p. A-2; Armour, S. (1994, Jan. 21). Study
ars neighborhood of
cancer link. The Ames Daily Tribune, p. A-1; Ar
mour, S. (1994, May 2). DOE reviews
cancer studies. The Ames Daily
Tribune, p. A-1; Armour, S. (1994, May 20). $4 million
of toxic sites. The Ames Daily Tribune, p. A-1.
 Dunwoody, S., & Neuwirth, K. (199
1). Coming to terms with the impact of
communication on scientific an
d technological risk judgments. In L. Wilkins & P.
, Risky Business: Communicating Issues of Science, Risk, and Public
Policy (pp. 243-286). Beverly Hills, CA: Sage.
 Morgan, M. G. (1993, July). Risk a
nalysis and management. Scientific American, 269
(1), pp. 32-41.
 Fischhoff, B.,
Slovic, P., Lichtenstein, S., Read, S., & Combs, B. (1978). How
is safe enough? A psychometric study of attitudes toward technological risks
benefits. Policy Sciences, 9, pp. 127-152.
 Slovic, P., Fischhoff, B
., & Lichtenstein, S. (1985). Characterizing perceived
risk. In R. W.
Kates, D. Hohenemser, & J. Kasperson (Eds.) Perilous Progress:
hnology as Hazard (pp. 91-123). Boulder CO: Westview.
 Englander, T., Farago, K., S
lovic, P., & Fischhoff, B. (1986). A comparative
analysis of risk per
ception in Hungary and the United States. Social Behavior, 1, pp.
5-66; Namur, E., & Sornay, C. (1988). La perception des risques sociaux
societal risks). Villeneuve d'Ascq: Universite Charles-de-Gaulle;
R., & Rosa, E. A. (1991). Cognitive representation of risk
s: A comparison of
Japan and the United States. Journal of Cross-Cultural Psychology,
22, pp. 11-28;
Teigen, K. H., Brun, W., & Slovic, P. (1988). Societ
al risk as seen by a Norwegian
public. Journal of Behavioral Decisi
on Making, 1, pp. 111-130.; Keown, C. F. (1989).
Risk perception of
Hong Kongese vs. Americans. Risk Analysis, 8, pp. 435-455.
 Mullett, E., Duquesnoy
, C., Raiff, P., Fahrasmane, R., & Namur, E. (1993). The
actor of risk perception. Journal of Applied Social Psychology, 23 (19),
pp. 1594-1605; Morgan, M. G., Slovic, P., Nair, I., Geisler, D.,
Fischhoff, B., Lincoln, D., & Florig, K. (1985). Powerline frequency
magnetic fields: A pilot study of risk perception. Ris
k Analysis, 5, 139-149; Slovic,
P., Fischhoff, B. & Lichtenstein, S
. (1985). Regulation of risk: A psychological
perspective. In R. G.
Noll (Ed.), Regulatory Policy and the Social Sciences (pp.
). Berkeley: University of California Press; Kraus, N. N., & Slovic, P. (1988).
Taxonomic analysis of perceived risk: Modeling individual and group
homogeneous hazard domains. Risk Analysis, 8, pp. 435-4
 Hohenemser, C. et al. (1986). Methods for analyzing and comparing
hazards. In V. Covello, J. Menkes, & J. Mumpower (Eds.),
ary Issues in Risk
Analysis : Vol. 1: Risk Evaluation and Managemen
t (pp. 249-274). New York: Plenum.
 Kleinhesselink & Rosa (1991); Mullet et al. (1
 Kraus, N. N., & Slovic, P. (1988). Taxonomic analysis of perceived risk:
individual and group perceptions within homogeneous hazard domains. Risk Analys
 Gregory, R., and Mendelsohn, R. (1993). P
erceived risk, dread, and benefits. Risk
Analysis 13 (3), pp. 259-264.
 Eyles, J
., Taylor, S. M., Baxter, J., Sider, D., & Willms, D. (1993). The social
construction of risk in a rural community: Responses of local residents to
Hagersville (Ontario) tire fire. Risk Analysis, 13 (3), pp.
; Fitchen, J. M.,
Heath, J. S., & Fessenden-Raden, J. (1987). Risk
perception in community context: A
case study. In B. B. Johnson & V
. T. Covello (Eds.), The Social and Cultural C
onstruction of Risk (
pp. 31-54.) Dordrecht: Reidel; Edelstein, M. R. (1988).
d Communities. Boulder, CO: Westview Press; Edelstein, M. R., & Wandersman,
A. (1987). Community dynamics in coping with toxic contaminants. In I.
Wandersman (Eds.), Neighborhood and Community Environment. New
 Kasperson, R. E., Renn, O., Slovic, P., Brown, H. S., Emel, J., Gob
Kasperson, J. X., & Ratick, S. (1988). The social amplificati
on of risk: A conceptual
framework. Risk Analysis 8 (2), pp. 177-18
 Renn, O. (1992). Concepts of risk: A classification. In S. Krimsky & D.
(Eds.), Social Theories of Risk (pp. 53-82). Westport, CT:
 Chaffee, S. (1982). Mass media and interpersonal channels: Competitive,
convergent, or complimentary? In G. Gumpert & R. Cathcart (Eds.),
Interpersonal Communication in a Media World (2nd ed., pp. 57-7
7). New York: Oxford
 Mazur, A., & Hall, G.
S. (1990). Effects of social influence and measured
exposure level o
n response to radon. Sociological Inquiry, 60 (3), pp. 274-284.
 Tyler, T. R. & Co
ok, F. L. (1984). The mass media and judgments about risk:
shing impact on personal and societal level judgments. Journal of Personality
and Social Psychology, 47 (4), pp. 693-708.
 Coleman, C. (1993). The in
fluence of mass media and interpersonal communication
on societal and
personal risk judgments. Communication Research 20, pp. 611-628.
 Armour (1994,
 Dillman, D. A. (1978). Mail and Telephone Surveys: The Total Design Met
York: John Wiley.
 Flynn, J., Burns, W., Mertz, C. K.,
& Slovic, P. (1992). Trust as a determinant
of opposition to a high-
level radioactive waste repository: An analysis of a structural
model. Risk Analysis 1
2 (3), pp. 417-429; Kasperson, R., Klaidman, S., Houk, V.,
ld, E., Blair, E. H., Lynn, F., Sandman, P., Alm, A., & Vacor, T. (1987). Trust
edibility: The central issue? In J. C. Davies, V. T. Covello, & F. W. Allen
(Eds.), Risk Communication (pp. 43-62). Washington, DC: The
 Isenberg, D. J. (1986). Group polarization: A critical review and
Journal of Personality and Social Psychology 50 (6), pp. 1141-1
151; Mackie, D. M.
(1986). Social identification effects in group p
olarization. Journal of Personality and
Social Psychology 50 (4), pp. 720-728; Pavitt,
C. (1994). Another view of group
polarizing: The reasons for one-s
ided argumentation. Communication Research 21 (5), pp.
 Chaiken, S., &
Yates, S. (1985). Affective-cognitive consistency and
attitude polarization. Journal of Personality and Social Psychology 49
(6), pp. 1470-1481.
 Eagly, A. H., & Chaiken, S. (1993). The Psychology of At
titudes. Fort Worth:
Harcourt Brace Jovanovich.
 Griffin, R J.,
& Dunwoody, S. (1995). Superficial and systematic uses of
n about environmental risks. Paper presented to "Communication and Our
Environment: An Interdisciplinary Conference," Chattanooga, TN, March 30 -