It is important 

not only to be 

able to describe 

how people differ

in the way they 

make judgments,

but also to be 

able to predict 

judgments more 






Public Perceptions of Risk
 By Melissa L. Finucane, Ph.D. 

Melissa Finucane is a visiting Research Associate with Decision Research, Eugene and a visiting scholar at the Institute for Cognitive and Decision Sciences, University of Oregon. She received a Ph.D. from the University of Western Australia. Her research interests are in human judgment, decision making, and risk perception. Currently she is focusing on the way emotion helps people to make sense of complex information about hazards.

Public perceptions of risk sometimes seem to owe little or nothing to the rigours of scientific method, resulting in much conflict with the scientists responsible for assessing and managing risk. Some hazards for which scientists estimate negligible risk, such as nuclear power plants, evoke outrage in lay people. For other hazards, such as radon, lay people seem to underestimate the risk and behave too complacently. Of particular interest to me is that the public reliably perceives a negative relationship between hazards’ risks and benefits, despite there being no relationship or, if anything, a positive relationship between many hazard’s risks and benefits in the external environment. Given the abundant information available to the public these days, I am investigating how they arrive at judgments of risk and benefit that differ from the conclusions made by scientists.


     Technically, risk and benefit are distinct concepts. The nature of the gains attained from pursuit of a hazardous activity or technology is qualitatively different from the nature of the risks. For instance, the benefit gained from using roller blades (e.g., entertaining pastime) is different from the risk (e.g., injury from a car collision). Driving to work, eating beef, and using a cellular phone are other examples of activities with distinct benefits and risks. Though distinct, risks and benefits generally tend to be positively correlated in the external environment. Whereas activities that bring great benefits may be high or low in risk, activities that are low in benefit are unlikely to be high in risk (if they were, they would be proscribed), suggesting a positive correlation between risk and benefit. In addition, economic data addressing the question “How safe is safe enough?” suggests that the level and acceptability of risk is positively related to the benefits (1).

     Although risk and benefit may be positively correlated in the environment and in economic analyses, numerous studies have shown them to be negatively related in peoples’ minds. The greater the perceived benefit of many hazards, the lower the perceived risk, and vice versa (2). Smoking, alcoholic beverages, and food additives tend to be seen as very high in risk and relatively low in benefit, while vaccines, antibiotics, and x-rays tend to be seen as very high in benefit and relatively low in risk.

     According to many scientists, lay people’s beliefs about risks and benefits are irrational. That is, risk perceptions that deviate from estimates of fatality rates or other “objective” indices are thought to arise from a lack of understanding of complex scientific and technical information (3). Some risk regulators believe that arming people with more information should reduce their scientific illiteracy and improve their judgments. That is, risk perceptions would be more “accurate” if people were provided with more complete information about product or technology attributes. Others believe that if people just listened to the facts, they would reach the same conclusions as experts (4). Despite extensive efforts to educate the public about risks and risk assessment, however, their estimations of risk tend to remain systematically biased. Compared with experts’ estimates, the public reliably overestimates some risks and underestimates others. As a result, the public is often dismissed as irrational, ineducable, and capricious.

     Empirical research, however, suggests that differing beliefs about risk may not in fact reflect differences in rationality or education (5). For instance, reliable risk perception differences can be found among scientists whom we can assume all understand appropriate technical information. That is, individuals may have the same technical understanding of risk and knowledge of risk assessment procedures but still differ in their risk perceptions.

     So if it’s not rationality or expertise that’s lacking, what leads people to believe risk and benefit are negatively correlated? The objective of recent research that my colleagues and I conducted was to investigate the possibility that risk and benefit are inversely related in people’s minds because an affective feeling is referred to when the risk or benefit of specific hazards is judged. Hints that affect (emotion) may be playing a role were revealed when Alhakami and Slovic observed that the relationship between perceived risk and perceived benefit was linked to an individual’s general affective evaluation of a hazard (6). If an activity was “liked,” people tended to judge its risks as low and its benefits as high. If the activity was “disliked,” the judgments were opposite —high risk and low benefit. Perhaps affect comes prior to, and directs, judgments of risk and benefit.

     Despite the evidence in support of the role of affect in judgment, an analytic (cognitive) interpretation of Alhakami and Slovic’s results cannot be excluded completely. Their experimental design could not rule out the possibility that risk and benefit judgments are correlated negatively because individuals approach the judgment tasks analytically, producing a “net riskiness” or “net benefit” judgment rather than independent judgments of risk and benefit. That is, individuals may be making judgments (regardless of whether the rating scale focuses only on risk or on benefit) by deliberating on what the net difference between risk and benefit is for any particular item. Our latest research has attempted to rule out the possibility of an analytic explanation for the inverse risk/benefit relationship using two different methodologies.

Recent studies

     Evidence supporting the affect hypothesis was obtained in two experimental studies conducted recently (7).

     In the first study, participants were asked to judge the risk and benefit of 23 hazards under conditions of time pressure (n= 28) or no time pressure (n = 26). As expected, risk and benefit judgments of the hazards were found to be more strongly negatively correlated under time pressure (mean r = -0.37) than no time pressure (mean r = -0.12) for most items. Under time-pressure, 13 correlations were significantly negative, while only two items showed a significant negative correlation under no time pressure. That is, the confounding between perceived risk and perceived benefit seemed to be stronger when the opportunity for logical deliberation was restricted, and reliance on affective reactions to hazards presumably was increased. In the second study (n=219), we found that experimentally manipulating the salience of one affective dimension of information about hazards affected ratings on the non-manipulated dimension. That is, giving people high benefit (risk) information led to decreased risk (benefit) ratings, and giving people low benefit (risk) information led to increased risk (benefit) ratings. The latter results (i.e., from the low benefit/risk information manipulation) were contrary to the pattern of ratings expected if people used a strategy such as the availability heuristic (which would predict little systematic effect on the non-manipulated dimension). Importantly, the second study showed that the inverse relationship between perceived risk and perceived benefit found in the first study is causally determined.

     Despite using different methodologies, the first and second studies suggest that risk and benefit are linked somehow in people’s perceptions, consequently influencing their judgments. Based on recent work emphasizing the crucial role of images marked by positive and negative feelings in judgment, and the fundamental influence of affect as motivator of behavior, it is plausible that perceived risk and perceived benefit are linked via some sort of affective commonality. A parsimonious explanation is that the positive and negative feelings attached to the images people associate with hazards are available and influential when risk and benefit are judged. That is, representations of objects and events in people’s minds are tagged to varying degrees with affect, and the pool of affective tags is referred to for quick evaluations. In this way judgments of risk and benefit are guided and linked by affect. We call this mental short-cut the “affect heuristic” because it is like a rule of thumb that improves judgmental efficiency by deriving both risk and benefit evaluations from a common source—affective reactions to the stimulus item.


     By demonstrating that affect plays a crucial role in judgment, we can understand why public beliefs about risk seem to have little relationship to the traditional science of risk assessment. This outcome has great theoretical and practical importance. Our results suggest a fruitful direction for the development of more accurate theories of human judgment. It is important not only to be able to describe how people differ in the way they make judgments (and hence end up with different beliefs), but also to be able to predict judgments more accurately. Our focus on affect as a central component of human judgments about risks and benefits is something not considered by researchers to date. Traditionally, the main focus of descriptive decision research has been cognitive, rather than affective. When principles of utility maximization appeared to be descriptively inadequate, cognitive information-processing models were developed based on concepts such as bounded rationality and satisficing. The field of judgment and decision making research has given little attention until very recently to the importance of affect, and the field of risk analysis has given affect no attention at all.

     The practical benefits flow from the theoretical advances. Better predictive capacity of theories will help us to anticipate when conflicts about risk might arise. Currently there are tremendous economic and social costs associated with risk management processes dominated heavily by technical perspectives. Indeed, addressing risk controversies with technical solutions may be responsible for escalating conflict.

Future directions

     Several directions look enticing for future research. One direction is to investigate the extent to which scientists demonstrate an affective judgment process, particularly when making judgments outside their area of primary expertise. I expect that using the affect heuristic to simplify complex judgment information is in fact an adaptive and useful strategy in many situations, and is relied on by everyone to greater or lesser extents depending on the context. A second direction is to investigate the role of affect in beliefs about the stockmarket that seem to suggest little understanding of rational economic principles. For example, perhaps some people are more prone than others to investing in high-performing stocks (despite their likelihood of regressing towards the mean), due to an affectively-based judgment that high benefit means low risk. Thirdly, I intend to explore more direct methods for measuring the underlying affective mechanisms by which judgments are made, as well as the interplay between affect and analysis in the development of beliefs.

[Footnotes unavailable]

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© 2001 Oregonians for Rationality