European Journal of Operational Research 177 (2007) 1333–1352 www.elsevier.com/locate/ejor

The affect heuristic q

Paul Slovic *, Melissa L. Finucane, Ellen Peters, Donald G. MacGregor

Decision Research Inc., 1201 Oak Street, Suite 200, Eugene, OR 97401, USA

Available online 16 October 2006

Abstract

This paper introduces a theoretical framework that describes the importance of affect in guiding judgments and deci- sions. As used here, ‘‘affect’’ means the specific quality of ‘‘goodness’’ or ‘‘badness’’ (i) experienced as a feeling state (with or without consciousness) and (ii) demarcating a positive or negative quality of a stimulus. Affective responses occur rapidly and automatically—note how quickly you sense the feelings associated with the stimulus word ‘‘treasure’’ or the word ‘‘hate’’. We argue that reliance on such feelings can be characterized as ‘‘the affect heuristic’’. In this paper we trace the development of the affect heuristic across a variety of research paths followed by ourselves and many oth- ers. We also discuss some of the important practical implications resulting from ways that this heuristic impacts our daily lives. Ó 2002 Cambridge University Press. Published by Elsevier B.V.

Keywords: Affect heuristic; Judgment; Decision making; Risk perception

1. Background nized as an important component of human judg- ment and decision making. Perhaps befitting its Although affect has long played a key role in rationalistic origins, the main focus of descriptive many behavioral theories, it has rarely been recog- decision research has been cognitive, rather than affective. When principles of utility maximization appeared to be descriptively inadequate, Simon q Reprinted from Gilovich, T., Griffin, D., Kahneman, D. (1956) oriented the field toward problem solving (Eds.), 2002. Heuristics and Biases: The Psychology of Intuitive and information-processing models based upon Judgment. Cambridge University Press, New York. pp. 397– 420. Ó Cambridge University Press 2002. Reprinted with per- bounded rationality. The work of Tversky and mission. Financial support for the writing of this paper was Kahneman (1974) and Kahneman et al. (1982) provided by the National Science Foundation under Grant SES demonstrated how boundedly rational individuals 9876587. * employ heuristics such as availability, representa- Corresponding author. Tel.: +1 541 485 2400; fax: +1 541 tiveness, and anchoring and adjustment to make 485 2403. E-mail address: [email protected] (P. Slovic). judgments and how they use simplified strategies URL: http://www.decisionresearch.org (P. Slovic). such as ‘‘elimination by aspects’’ to make choices

0377-2217/$ - see front matter Ó 2002 Cambridge University Press. Published by Elsevier B.V. doi:10.1016/j.ejor.2005.04.006 1334 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352

(Tversky, 1972). Other investigators elaborated the matic, natural, nonverbal, narrative, and cognitive strategies underlying judgment and experiential, and the other analytical, deliberative, choice through models of constructed preferences verbal, and rational. (p. 710) (Slovic, 1995; Payne et al., 1993), dominance struc- One of the characteristics of the experiential turing (Montgomery, 1983), and comparative system is its affective basis. Although analysis is advantages (Shafir et al., 1989). In 1993, the entire certainly important in some decision-making cir- volume of the journal Cognition was dedicated to cumstances, reliance on affect and emotion is a the topic, Reason-Based Choice, in which it was quicker, easier, and more efficient way to navigate argued that ‘‘Decisions ... are often reached by in a complex, uncertain, and sometimes dangerous focusing on reasons that justify the selection of world. Many theorists have given affect a direct one option over another’’ (Shafir et al., 1993, p. and primary role in motivating behavior. Epstein’s 34). Similarly, a state-of-the-art review by Buse- (1994) view on this is as follows: meyer et al. (1995) was titled ‘‘Decision Making from a Cognitive Perspective’’. In keeping with The experiential system is assumed to be intimately its title, it contained almost no references to the associated with the experience of affect, ... which influence of affect on decisions. refer[s] to subtle feelings of which people are often Despite this cognitive emphasis, the importance unaware. When a person responds to an emotion- of affect is being recognized increasingly by deci- ally significant event ... the experiential system sion researchers. A limited role for affect was automatically searches its memory banks for acknowledged by Shafir et al. (1993) who conceded related events, including their emotional accompa- that ‘‘People’s choices may occasionally stem from niments ... If the activated feelings are pleasant, affective judgments that preclude a thorough eval- they motivate actions and thoughts anticipated to uation of the options’’ (p. 32, emphasis added). reproduce the feelings. If the feelings are unpleas- A strong early proponent of the importance of ant, they motivate actions and thoughts antici- affect in decision making was Zajonc (1980), who pated to avoid the feelings. (p. 716) argued that affective reactions to stimuli are often Also emphasizing the motivational role of the very first reactions, occurring automatically affect, Mowrer (1960a,b) conceptualized condi- and subsequently guiding information processing tioned emotional responses to images as prospec- and judgment. According to Zajonc, all percep- tive gains and losses that directly ‘‘guide and tions contain some affect. ‘‘We do not just see ‘a control performance in a generally sensible adap- house’: We see a handsome house, an ugly house, tive manner’’ (1960a, p. 30). He criticized theorists or a pretentious house’’ (p. 154). He later adds, who postulate purely cognitive variables such as ‘‘We sometimes delude ourselves that we proceed expectancies (probabilities) intervening between in a rational manner and weight all the pros and stimulus and response, cautioning that we must cons of the various alternatives. But this is proba- be careful not to leave the organism at the choice bly seldom the actual case. Quite often ‘‘I decided point ‘‘lost in thought’’. Mowrer’s solution was in favor of X’’ is no more than ‘‘I liked X ...’’ We to view expectancies more dynamically (as condi- buy the cars we ‘‘like’’, choose the jobs and houses tioned emotions such as hopes and fears) serving we find ‘‘attractive’’, and then justify these choices as motivating states leading to action. by various reasons...’’ (p. 155). One of the most comprehensive and dramatic Affect also plays a central role in what have theoretical accounts of the role of affect in decision come to be known as ‘‘dual-process theories’’ of making is presented by the neurologist, Antonio thinking, knowing, and information processing. Damasio (1994), in his book Descartes’ Error: As Epstein (1994), has observed, Emotion, Reason, and the Human Brain. Damasio’s There is no dearth of evidence in every day life that theory is derived from observations of patients people apprehend reality in two fundamentally dif- with damage to the ventromedial frontal cortices ferent ways, one variously labeled intuitive, auto- of the brain that has left their basic intelligence, P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 1335 memory, and capacity for logical thought intact cludes that somatic markers increase the accuracy but has impaired their ability to ‘‘feel’’—that is, and efficiency of the decision process and their to associate affective feelings and emotions with absence degrades decision performance. the anticipated consequences of their actions. Damasio tested the somatic marker hypothesis Close observation of these patients combined with in a decision making experiment in which subjects a number of experimental studies led Damasio to gambled by selecting cards from any of four decks. argue that this type of brain damage induces a Turning each card resulted in the gain or loss of a form of sociopathy (Damasio et al., 1990) that sum of money, as revealed on the back of the card destroys the individual’s ability to make rational when it was turned. Whereas normal subjects and decisions; that is, decisions that are in his or her patients with brain lesions outside the prefrontal best interests. Persons suffering this damage sectors learned to avoid decks with attractive large became socially dysfunctional even though they payoffs but occasional catastrophic losses, patients remain intellectually capable of analytical with frontal lobe damage did not, thus losing a reasoning. great deal of money. Although these patients Commenting on one particularly significant responded normally to gains and losses when they case, Damasio observes: occurred (as indicated by skin conductance responses immediately after an outcome was expe- The instruments usually considered necessary and rienced) they did not seem to learn to anticipate sufficient for rational behavior were intact in future outcomes (e.g., they did not produce nor- him. He had the requisite knowledge, attention, mal skin conductance responses when contemplat- and memory; his language was flawless; he could ing a future choice from a dangerous deck). In perform calculations; he could tackle the logic of other words, they failed to show any proper antic- an abstract problem. There was only one signifi- ipatory responses, even after numerous opportuni- cant accompaniment to his decision-making fail- ties to learn them. ure: a marked alteration of the ability to Despite the increasing popularity of affect in experience feelings. Flawed reason and impaired research programs and recent attempts to feelings stood out together as the consequences acknowledge the importance of the interplay of a specific brain lesion, and this correlation sug- between affect and cognition, further work is gested to me that feeling was an integral compo- needed to specify the role of affect in judgment nent of the machinery of reason. (p. XII) and decision making. The ideas articulated below In seeking to determine ‘‘what in the brain are intended as a step toward encouraging the allows humans to behave rationally’’, Damasio development of theory about affect and decision argues that thought is made largely from images, making and demonstrating how such a theory broadly construed to include sounds, smells, real can be tested. or imagined visual impressions, ideas, and words. The basic tenet of this paper is that images, A lifetime of learning leads these images to become marked by positive and negative affective feelings, ‘‘marked’’ by positive and negative feelings linked guide judgment and decision making. Specifically, directly or indirectly to somatic or bodily states it is proposed that people use an affect heuristic to (Mowrer and other learning theorists would call make judgments. That is, representations of this conditioning): ‘‘In short, somatic markers objects and events in people’s minds are tagged are ... feelings generated from secondary emotions. to varying degrees with affect. In the process of These emotions and feelings have been connected, making a judgment or decision, people consult or by learning, to predicted future outcomes of certain refer to an ‘‘affect pool’’ containing all the positive scenarios’’ (Damasio, 1994, p. 174). When a nega- and negative tags consciously or unconsciously tive somatic marker is linked to an image of a associated with the representations. Just as imagi- future outcome it sounds an alarm. When a posi- nability, memorability, and similarity serve as cues tive marker is associated with the outcome image, for probability judgments (e.g., the availability it becomes a beacon of incentive. Damasio con- and representativeness heuristics), affect may serve 1336 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 as a cue for many important judgments. Using an the ideograph on a scale of liking. Mean liking rat- overall, readily available affective impression can ings were significantly higher for ideographs pre- be far easier—more efficient—than weighing the ceded by smiling faces. This effect was lasting. In pros and cons or retrieving from memory many a second session, ideographs were primed by the relevant examples, especially when the required ‘‘other face’’, the one not associated with the stim- judgment or decision is complex or mental ulus in the first session. This second priming was resources are limited. This characterization of a ineffective because the effect of the first priming mental short-cut leads to labeling the use of affect remained. a ‘‘heuristic’’. It is not just subliminal smiles that affect our judgment. La France and Hecht (1995) found that students accused of academic misconduct who 2. Empirical evidence were pictured as smiling received less punishment than nonsmiling transgressors. Smiling persons 2.1. Manipulating preferences through controlled were judged as more trustworthy, good, honest, exposures genuine, obedient, blameless, sincere, and admira- ble than nonsmiling targets. The fundamental nature and importance of The perseverance of induced preferences was affect has been demonstrated repeatedly in a tested by Sherman et al. (1998) who asked partic- remarkable series of studies by Robert Zajonc ipants to study Chinese characters and their Eng- and his colleagues (see, e.g., Zajonc, 1968). The lish meanings. Half of the meanings were positive concept of stimulus exposure is central to all of (e.g., beauty), half were negative (e.g., disease). these studies. The central finding is that, when Then participants were given a test of these mean- objects are presented to an individual repeatedly, ings followed by a task in which they were given the ‘‘mere exposure’’ is capable of creating a posi- pairs of characters and were asked to choose the tive attitude or preference for these objects. one they preferred. Participants preferred charac- In the typical study, stimuli such as nonsense ters with positive meaning 70% of the time. Next, phrases, or faces, or Chinese ideographs are pre- the characters were presented with neutral mean- sented to an individual with varying frequencies. ings (desk, linen) and subjects were told that these In a later session, the individual judges these stim- were the ‘‘true’’ meanings. The testing procedure uli on liking, or familiarity, or both. The more fre- was repeated and, despite learning the new mean- quent the prior exposure to a stimulus, the more ings, the preferences remained the same. Charac- positive the response. A meta-analysis by Born- ters that had been initially paired with positive stein (1989) of mere exposure research published meanings still tended to be preferred. between 1968 and 1987 included over 200 experi- These various studies demonstrate that affect is ments examining the exposure–affect relationship. a strong conditioner of preference, whether or not Unreinforced exposures were found to reliably the cause of that affect is consciously perceived. enhance affect toward visual, auditory, gustatory, They also demonstrate the independence of affect abstract, and social stimuli. from cognition, indicating that there may be con- Winkielman et al. (1997) demonstrated the ditions of affective or emotional arousal that do speed with which affect can influence judgments not necessarily require cognitive appraisal. This in studies employing a subliminal priming para- affective mode of response, unburdened by cogni- digm. Participants were ‘‘primed’’ through expo- tion and hence much faster, has considerable sure to a smiling face, a frowning face, or a adaptive value. neutral polygon presented for 1/250 of a second, an interval so brief that there is no recognition 2.2. Evaluating gambles or recall of the stimulus. Immediately following this exposure, an ideograph was presented for The affect heuristic can explain a finding that two seconds, following which the participant rated has intrigued and perplexed the first author since P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 1337 he first observed it in 1984. Slovic and Amos Tver- attractiveness rating 80–90% of the time, but was sky were reexamining the early studies of Slovic assigned a higher price only 10–15% of the time). and Lichtenstein (1968) and Lichtenstein and Slo- The mean evaluations of the following two bets vic (1971, 1973), which pointed at compatibility were typical: between stimulus attributes and response scales as an explanation for preference reversals. Such reversals were exhibited when an individual chose Mean Mean Gamble A (with a high probability of winning a Price Rating (0–20 scale) modest amount of money) over Gamble B (with 29/36 to win $2 $1.25 13.2 a smaller probability of a larger payoff) but 7/36 to win $9 $2.11 7.5 assigned a larger monetary value (buying price or selling price) to Gamble B. Presumably the rever- sal occurred because the gamble payoffs were given more weight in the pricing response mode than in Seeking to explain these results in terms of com- choice, due to the compatibility between prices and patibility, we linked the compatibility effect to the payoffs, both of which were measured in dollars. ease of mapping the stimulus component of a gam- Tversky and Slovic decided to replicate the ear- ble onto the response scale. The easier it is to exe- lier reversal studies with three changes: cute such a mapping, the greater the weight given 1. The complexity of the gamble was minimized the component. In principle, a gamble’s payoff is by eliminating losses. Each gamble consisted more compatible with a price response than with merely of a stated probability of winning a given a rating, because prices and payoffs are both amount. There was no possible loss of money. expressed in dollars. Hence payoffs should get 2. Following Goldstein (later Goldstein and greater weight in pricing than in rating. The extre- Einhorn, 1987), who observed reversals with rat- mely high weight given probabilities when rating ings and prices, we included ratings of a gamble’s attractiveness may be explained by the fact that attractiveness along with choices and pricing as the probabilities are more readily coded as attrac- methods of eliciting preferences. The attractiveness tive or unattractive than are the payoffs. For scale ranged between 0 (not at all attractive) and example, 29 out of 36 chances to win are very 20 (very attractive). attractive odds. On the other hand, a $9 payoff 3. To ensure the strategic equivalence of our may be harder to map on a rating scale because three elicitation procedures, we devised a method its attractiveness depends on what other payoffs for linking preferences to outcomes that was iden- are available. tical across all conditions. Subjects were told that a According to this explanation, if we could make pair of bets would be selected and the bet that a gamble’s payoff more compatible with the attrac- received the higher attractiveness rating (or the tiveness rating, we would presumably enhance the higher price, or that was preferred in the choice weight given to payoff in the rating response mode. task) would be the bet they would play. Conse- We attempted to do this in a new experiment, quently, the preferences elicited by prices and rat- focusing on the gamble 7/36 to win $9. To make ings should not differ from each other or from the the payoff more compatible with regard to the preferences elicited by direct choices. Some of the scale of attractiveness, we added a very small loss gambles were, in fact, actually played. (5¢) to the gamble Using this design, we observed strong differ- 7=36 win $9; ences between response modes, leading to many 29=36 lose 5!. preference reversals. Particularly striking was the difference between ratings and prices. Ratings pro- Whereas the attractiveness of $9 might not be duced an overwhelming dominance of high proba- readily apparent, we reasoned that a bet offering bility bets over high payoff bets (the bet with $9 to win and only 5¢ to lose should appear to higher probability of winning had the higher have a very attractive payoff ratio. This led us to 1338 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 predict that one might increase the attractiveness ardous facility into a region might stigmatize of a gamble (p to win X) by adding a loss compo- that region and cause people to avoid going there nent to it. to recreate, retire, or do business. Believing self- The results exceeded our expectations. The report to be unreliable (‘‘If they build it, will you gamble with no loss had the lower attractiveness not come?’’), research on stigmatization was con- rating (mean = 9.4 on the 0–20 scale). Adding a ducted through a number of empirical studies 5¢ loss led to a much higher attractiveness rating designed to examine the relationship between (mean = 14.9). Even the bet imagery, affect, and decision making. After con- ducting these studies, we learned that they fit clo- 7=36 win $9; sely with a large body of existing theory and 29=36 lose 25!. research such as the work of Damasio, Mowrer, and Epstein, described earlier. was judged more attractive (mean = 11.7) than the Several empirical studies have demonstrated a bet with no loss. strong relationship between imagery, affect, and Would adding a small loss to the gamble decision making. Many of these studies used a enhance its attractiveness in choice as it did in rat- word-association technique. This method involves ing? We recently addressed this question by asking presenting subjects with a target stimulus, usually 96 University of Oregon students to choose a word or very brief phrase, and asking them to between playing a gamble, and receiving a gain provide the first thought or image that comes to of $2. For half of the students, the gamble was mind. The process is then repeated a number of 7/36 to win $9; for the others, the gamble had times, say three to six, or until no further associa- the 5¢ loss. Whereas only 33.3% chose the $9 gam- tions are generated. Following the elicitation of ble over the $2, 60.8% chose the ($9; À5¢) gamble images, subjects are asked to rate each image they over the $2. A replication study with $4 as the give on a scale ranging from very positive (e.g., alternative to the gamble produced similar results. +2) to very negative (e.g., À2), with a neutral point The enhancement produced by adding a small loss in the center. Scoring is done by summing or aver- thus holds for choices as well as for rating aging the ratings to obtain an overall index. responses. This imagery method has been used successfully The enhanced attractiveness produced by small to measure the affective meanings that influence losses was originally predicted and explained in people’s preferences for different cities and states terms of compatibility, and we now see it also as (Slovic et al., 1991), as well as their support or an example of the affect heuristic. This broader opposition to technologies such as nuclear power perspective was induced, in part, by results (Peters and Slovic, 1996). obtained later by Mellers et al. (1992) and Hsee Table 1 illustrates the method in a task where (1995, 1996a,b, 1998) and by our own subsequent one respondent was asked to give associations to studies of imagery, affect, and decision making. each of two cities and, later, to rate each image These convergent streams of research are described affectively. The cities in this example show a clear in the following sections. affective preference for San Diego over Denver. Slovic et al. (1991) showed that summed image 2.3. Image, affect, and decision making scores such as these were highly predictive of expressed preferences for living in or visiting cities. The early anomalous findings with gambles In one study they found that the image score pre- were laid aside while other means of explaining dicted the location of actual vacations during the the differences between ratings, choices, and pric- next 18 months. ing responses were developed (see Tversky et al., Subsequent studies have found affect-laden 1990). At the same time, Slovic and colleagues at imagery elicited by word associations to be predic- Decision Research embarked on a research pro- tive of preferences for investing in new companies gram designed to test whether introducing a haz- on the stock market (MacGregor et al., 2000) and P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 1339

Table 1 How much would you like a roommate said to Images, ratings, and summation scores for one respondent be both intelligent and obnoxious? Anderson Stimulus Image Image Image (1981) has shown that the integration of multiple number rating pieces of information into an impression of this San Diego 1 Very nice 2 sort can be described well by a weighted average San Diego 2 Good beaches 2 model where separate weights are given to intelli- San Diego 3 Zoo 2 gence and obnoxiousness, respectively. Mellers San Diego 4 Busy freeway 1 San Diego 5 Easy to find way 1 et al. (1992) further showed that the weights in San Diego 6 Pretty town 2 such integrative tasks are inversely proportional Sum = 10 to the variance of the impressions. Thus we would expect the impression produced by the combina- Denver 1 High 2 tion of these two traits to be closer to the impres- Denver 2 Crowded 0 sion formed by obnoxiousness alone, reflecting Denver 3 Cool 2 greater weight given to obnoxiousness due to its Denver 4 Pretty 1 Denver 5 Busy airport À2 smaller variance (more precise affective mapping). Denver 6 Busy streets À2 The meaning of a stimulus image appears to be reflected in the precision of the affective feelings Sum = 1 associated with that image. More precise affective Note: Based on these summation scores, this person’s predicted impressions reflect more precise meanings and preference for a vacation site would be San Diego. Source: Slovic et al. (1991). carry more weight in impression formation, judg- ment, and decision making. predictive of adolescents’ decisions to take part in Hsee (1996a,b, 1998) has developed the notion health-threatening and health-enhancing behav- of evaluability to describe the interplay between iors such as smoking and exercise (Benthin et al., the precision of an affective impression and its 1995). meaning or importance for judgment and decision making. Evaluability is illustrated by an experi- 2.4. Evaluability ment in which Hsee asked people to assume they were music majors looking for a used music dictio- The research with images points to the impor- nary. In a joint-evaluation condition, participants tance of affective impressions in judgments and were shown two dictionaries, A and B (see Table decisions. However, the impressions themselves 2), and asked how much they would be willing to may vary not only in their valence but in the pre- pay for each. Willingness-to-pay was far higher cision with which they are held. It turns out that for Dictionary B, presumably because of its greater the precision of an affective impression substan- number of entries. However, when one group of tially impacts judgments. participants evaluated only A and another group We shall refer to the distributional qualities of evaluated only B, the mean willingness to pay affective impressions and responses as ‘‘affective was much higher for Dictionary A. Hsee explains mappings’’. Consider, for example, some questions posed by Mellers et al. (1992): ‘‘How much would you like a potential roommate if all you knew Table 2 about her was that she was said to be intelligent?’’ Attributes of two dictionaries in Hsee’s study Or, ‘‘Suppose, instead, all you knew about her was Year of Number of Any defects? that she was said to be obnoxious?’’ Intelligence is publication entries a favorable trait but it is not very diagnostic (e.g., Dictionary A 1993 10,000 No, it’s like new meaningful) for likeableness, hence its affective Dictionary B 1993 20,000 Yes, the cover is map is rather diffuse. In contrast, obnoxiousness torn; otherwise it’s will likely produce a more precise and more nega- like new tive impression. Source: Adapted from Hsee (1998). 1340 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 this reversal by means of the evaluability principle. ing it to carry great weight in many judgment He argues that, without a direct comparison, the tasks. This is a representation characterizing an number of entries is hard to evaluate, because the attribute as a proportion or percentage of some- evaluator does not have a precise notion of how thing, or as a probability. At the suggestion of good or how bad 10,000 (or 20,000) entries is. How- Chris Hsee (personal communication), we shall ever, the defects attribute is evaluable in the sense refer to the strong effects of this type of represen- that it translates easily into a precise good/bad tation as ‘‘proportion dominance’’. response and thus it carries more weight in the Proportion (or probability) dominance was evi- independent evaluation. Most people find a defec- dent in the studies of gambles described at the tive dictionary unattractive and a like-new one beginning of this paper. Ratings of a gamble’s attractive. Under joint evaluation, the buyer can attractiveness tend to be determined far more see that B is far superior on the more important strongly by the probabilities of winning and losing attribute, number of entries. Thus number of than by the monetary payoffs. The curious finding entries becomes evaluable through the comparison that adding a small loss to a gamble increases its process. rated attractiveness, explained originally as a com- According to the evaluability principle, the patibility effect, can now be seen to fit well with the weight of a stimulus attribute in an evaluative notions of affective mapping and evaluability. judgment or choice is proportional to the ease or According to this view, a probability maps rel- precision with which the value of that attribute atively precisely onto the attractiveness scale (or a comparison on the attribute across alterna- because probability has a lower and upper bound tives) can be mapped into an affective impression. (0 and 1) and a midpoint below which a probabil- In other words, affect bestows meaning on infor- ity is ‘‘poor’’ or ‘‘bad’’ (i.e., has worse than an even mation (cf., Osgood et al., 1957; Mowrer, chance) and above which it is ‘‘good’’ (i.e., has a 1960a,b) and the precision of the affective meaning better than even chance). People know where a influences our ability to use information in judg- given value, such as 7/36, falls within the bounds, ment and decision making. Evaluability can thus and exactly what it means—‘‘I’m probably not be seen as an extension of the general relationship going to win’’. In contrast, the mapping of a dollar between the variance of an impression and its outcome (e.g., $9) onto the attractiveness scale is weight in an impression-formation task (Mellers diffuse, reflecting a failure to know how good or et al., 1992). bad or how attractive or unattractive $9 is. Thus, Hsee’s work in evaluability is noteworthy the impression formed by the gamble offering $9 because it shows that even very important attri- to win with no losing payoff is dominated by the butes may not be used by a judge or decision relatively precise and unattractive impression pro- maker unless they can be translated precisely into duced by the 7/36 probability of winning. How- an affective frame of reference. As described in ever, adding a very small loss to the payoff the next section, Hsee finds evaluability effects dimension brings the $9 payoff into focus and thus even with familiar attributes such as the amount gives it meaning. The combination of a possible $9 of ice cream in a cup (Hsee, 1998). We will also gain and a 5¢ loss is a very attractive win/loss ratio, demonstrate similar effects with other familiar con- leading to a relatively precise mapping onto the cepts such as amounts of money or human lives. upper end of the scale. Whereas the imprecise mapping of the $9 carries little weight in the aver- 2.5. Proportion dominance aging process, the more precise and now favorable impression of ($9; À5¢) carries more weight, thus In situations that involve uncertainty about leading to an increase in the overall favorability whether we will win or lose or that involve ambi- of the gamble. guity about some quantity of something (i.e., The effect of adding a small loss to the gamble how much is enough), there appears to be one can also be explained by norm theory (Kahneman information format that is highly evaluable, lead- and Miller, 1986). But a norm-theoretical explana- P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 1341 tion is consistent with an affective account. It and hence is readily evaluable and highly weighted asserts that the gamble with no loss is a relatively in the support judgment. Subsequent reduction of mediocre representative of the set of all positive the percentage of 150 lives that would be saved to gambles whereas the gamble with a small loss is 95%, 90%, and 85% led to reduced support for the a relatively attractive member of the class of mixed safety measure but each of these percentage condi- (win/loss) gambles. tions still garnered a higher mean level of support Proportion dominance surfaces in a powerful than did the save 150 lives condition (see Table 3). way in a very different context, the life-saving inter- Turning to a more mundane form of proportion ventions studied by Fetherstonhaugh et al. (1997), dominance, Hsee (1998) found that an overfilled Baron (1997), Jenni and Loewenstein (1997) and ice cream container with 7 oz. of ice cream was val- Friedrich et al. (1999). For example, Fetherston- ued more highly (measured by willingness to pay) haugh et al. found that people’s willingness to inter- than an underfilled container with 8 oz. of ice vene to save a stated number of lives was cream (see Fig. 1). This ‘‘less is better effect’’ determined more by the proportion of lives saved reversed itself when the options were juxtaposed than by the actual number of lives that would be and evaluated together. Thus, the proportion of saved. However, when two or more interventions the serving cup that was filled appeared to be more were directly compared, number of lives saved evaluable (in separate judgments) than the abso- become more important than proportion saved. lute amount of ice cream. Thus, number of lives saved, standing alone, appears to be poorly evaluable, as was the case 2.6. Insensitivity to probability for number of entries in Hsee’s music dictionaries. With a side-by-side comparison, the number of lives Outcomes are not always affectively as vague as became clearly evaluable and important, as also the quantities of money, ice cream, and lives that happened with the number of dictionary entries. Slovic (unpublished), drawing upon proportion dominance and the limited evaluability of numbers of lives, predicted (and found) that people, in a between-groups design, would more strongly sup- port an airport-safety measure expected to save 98% of 150 lives at risk than a measure expected to save 150 lives. Saving 150 lives is diffusely good, hence only weakly evaluable, whereas saving 98% of something is clearly very good because it is so Fig. 1. Stimuli in ice cream study by Hsee (1998). Participants close to the upper bound on the percentage scale, were given the sizes of the cups and the amounts of ice cream.

Table 3 Proportion dominance and airport safety Potential benefit Save 150 lives Save 98% Save 95% Save 90% Save 85% Mean supporta 10.4 13.6 12.9 11.7 10.9 Mediana 9.8 14.3 14.1 11.3 10.8 % of ratings P 13 37 75 69 35 31 Saving a percentage of 150 lives receives higher support ratings than does saving 150 lives. a Cell entries in these rows describe mean and median responses to the question: ‘‘How much would you support this proposed measure to purchase the new equipment?’’ (Critics argue that the money spent on this system could be better spent enhancing other aspects of airport safety). The response scale ranged from 0 (would not support at all) to 20 (very strong support). An overall ANOVA resulted in F4200 = 3.36, p = .01. The save 98% and save 95% conditions were both significantly different from the save 150 lives condition at p < .05, Tukey HSD test. 1342 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 were dominated by proportion in the above exper- of dollars, ice cream, and lives, these quantities iments. When consequences carry sharp and may convey little meaning. Amounts of anything, strong affective meaning, as is the case with a lot- no matter how common or familiar or intrinsically tery jackpot or a cancer, the opposite phenomenon important, may in some circumstances not be occurs—variation in probability often carries too evaluable. little weight. As Loewenstein et al. (2001) observe, 4. Probabilities or proportions, on the other one’s images and feelings toward winning the lot- hand, often are highly evaluable, reflecting the ease tery are likely to be similar whether the probability with which people recognize that a high probabil- of winning is one in 10 million or one in 10,000. ity of a desirable outcome is good and a low prob- They further note that responses to uncertain situ- ability is bad. When the quantities or outcomes to ations appear to have an all or none characteristic which these probabilities apply are affectively pal- that is sensitive to the possibility rather than the lid, probabilities carry much more weight in judg- probability of strong positive or negative conse- ments and decisions. However, just the opposite quences, causing very small probabilities to carry occurs when the outcomes have precise and strong great weight. This, they argue, helps explain many affective meanings—variations in probability carry paradoxical findings such as the simultaneous too little weight. prevalence of gambling and the purchasing of insurance. It also explains why societal concerns 2.8. The affect heuristic in judgments of risk and about hazards such as nuclear power and exposure benefit to extremely small amounts of toxic chemicals fail to recede in response to information about the Another stream of research that, in conjunction very small probabilities of the feared consequences with many of the findings reported above, led us to from such hazards. Support for these arguments propose the affect heuristic, had its origin in the comes from Rottenstreich and Hsee (2001) who early study of risk perception reported by Fisch- show that, if the potential outcome of a gamble hoff et al. (1978). One of the findings in this study is emotionally powerful, its attractiveness or unat- and numerous subsequent studies was that percep- tractiveness is relatively insensitive to changes in tions of risk and society’s responses to risk were probability as great as from 0.99 to 0.01. strongly linked to the degree to which a hazard evoked feelings of dread (see also Slovic, 1987). 2.7. Mid-course summary Thus activities associated with cancer are seen as riskier and more in need of regulation than activi- We can now see that the puzzling finding of ties associated with less dreaded forms of illness, increased attractiveness for the gambles to which injury, and death (e.g., accidents). a loss was appended is part of a larger story that A second finding in the study by Fischhoff et al. can be summarized as follows: has been even more instrumental in the study of 1. Affect, attached to images, influences judg- the affect heuristic. This is the finding that judg- ments and decisions. ments of risk and benefit are negatively correlated. 2. The evaluability of a stimulus image is For many hazards, the greater the perceived bene- reflected in the precision of the affective feelings fit, the lower the perceived risk and vice versa. associated with that image. More precise affective Smoking, alcoholic beverages, and food additives, impressions reflect more precise meanings (i.e., for example, tend to be seen as very high in risk greater evaluability) and carry more weight in and relatively low in benefit, whereas vaccines, impression formation, judgment, and decision antibiotics, and X-rays tend to be seen as high in making. benefit and relatively low in risk. This negative 3. The anomalous findings from the experi- relationship is noteworthy because it occurs even ments with gambles, ice cream preferences, and when the nature of the gains or benefits from an life-saving interventions suggest that, without a activity is distinct, and qualitatively different from context to give affective perspective to quantities the nature of the risks. That the inverse relation- P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 1343 ship is generated in people’s minds is suggested by the fact that risk and benefits generally tend to be : positively (if at all) correlated in the world. Activ- Affect ities that bring great benefits may be high or low in risk but activities that are low in benefit are unli- kely to be high in risk (if they were, they would be proscribed).

A study by Alhakami and Slovic (1994) found Copyright John Wiley and Sons : that the inverse relationship between perceived risk Reprinted with permission Perceived Perceived : 2000 Ltd and perceived benefit of an activity (e.g., using pes- benefit risk Ó ticides) was linked to the strength of positive or Fig. 2. A model of the affect heuristic explaining the risk/ negative affect associated with that activity. This benefit confounding observed by Alhakami and Slovic (1994). result implies that people base their judgments of Judgments of risk and benefit are assumed to be derived by an activity or a technology not only on what they reference to an overall affective evaluation of the stimulus item. think about it but also on what they feel about it. If Source: Finucane et al. (2000). they like an activity, they are moved to judge the risks as low and the benefits as high; if they dislike providing information about risk should change it, they tend to judge the opposite—high risk and the perception of benefit and vice-versa (see low benefit. Fig. 3). For example, information stating that risk Alhakami and Slovic’s (1994) findings sug- was low for some technology should lead to more gested that use of the affect heuristic guides percep- positive overall affect that would, in turn, increase tions of risk and benefit as depicted in Fig. 2. If so, perceived benefit. Indeed, Finucane et al. (2000)

A Nuclear Power B Nuclear Power

Positive Positive

Information says Risk inferred Information says Benefits “Benefit is high”. to be low “Risk is low”. inferred to be high

D C Nuclear Power Nuclear Power

Negative Negative

Information says Risk inferred Information says Benefit “Benefit is low”. to be high “Risk is high”. inferred to be 2000. Copyright John Wiley and Sons Ltd. Reprinted with permission. low Ó

Fig. 3. Model showing how information about benefit (A) or information about risk (B) could increase the overall affective evaluation of nuclear power and lead to inferences about risk and benefit that coincide affectively with the information given. Similarly, information could decrease the overall affective evaluation of nuclear power as in C and D. Source: Finucane et al. (2000). 1344 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 conducted this experiment, providing four differ- one might expect these risk judgments to be uni- ent kinds of information designed to manipulate formly low and unvarying, resulting in little or affect by increasing or decreasing perceived risk no correlation with the ratings of affect. Instead, and increasing or decreasing perceived benefit. In there was a strong correlation across chemicals each case there was no apparent logical relation between affect and judged risk of a very small between the information provided (e.g., informa- exposure. When the affect rating was strongly neg- tion about risks) and the nonmanipulated variable ative, judged risk of a very small exposure was (e.g., benefits). The predictions were confirmed. high; when affect was positive, judged risk was When the information that was provided changed small. Almost every respondent (95 out of 97) either the perceived risk or the perceived benefit, showed this negative correlation (the median cor- an affectively congruent but inverse effect was relation was À0.50). Importantly, those toxicolo- observed on the nonmanipulated attribute as gists who produced strong inverse relations depicted in Fig. 3. These data support the theory between risk and benefit judgments in the first that risk and benefit judgments are causally deter- study also were more likely to exhibit a high corre- mined, at least in part, by the overall affective spondence between their judgments of affect and evaluation. risk in the second study. In other words, across The affect heuristic also predicts that using time two different tasks, reliable individual differences pressure to reduce the opportunity for analytic emerged in toxicologists’ reliance on affective pro- deliberation (and thereby allowing affective con- cesses in judgments of chemical risks. siderations freer rein), should enhance the inverse In the realm of finance, Ganzach (2001) found relationship between perceived benefits and risks. support for a model in which analysts base their In a second study, Finucane et al. showed that judgments of risk and return for unfamiliar stocks the inverse relationship between perceived risks upon a global attitude. If stocks were perceived as and benefits increased greatly under time pressure, good, they were judged to have high return and as predicted. These two experiments with judg- low risk, whereas if they were perceived as bad, ments of benefits and risks are important because they were judged to be low in return and high in they support the contention by Zajonc (1980) that risk. However, for familiar stocks, perceived risk affect influences judgment directly and is not sim- and return were positively correlated, rather than ply a response to a prior analytic evaluation. being driven by a global attitude. Further support for the model in Fig. 2 has come from two very different domains—toxicol- 2.9. Judgments of probability, relative frequency, ogy and finance. Slovic et al. (1999) surveyed mem- and risk bers of the British Toxicological Society and found that these experts, too, produced the same inverse The affect heuristic has much in common with relation between their risk and benefit judgments. the model of ‘‘risk as feelings’’ proposed by Loe- As expected, the strength of the inverse relation wenstein et al. (2001) and with dual process theo- was found to be mediated by these experts’ affec- ries put forth by Epstein (1994), Sloman (1996), tive reactions toward the hazard items being and others. Recall that Epstein argues that individ- judged. In a second study, these same toxicologists uals apprehend reality by two interactive, parallel were asked to make a ‘‘quick intuitive rating’’ for processing systems. The rational system is a delib- each of 30 chemical items (e.g., benzene, aspirin, erative, analytical system that functions by way of second hand cigarette smoke, dioxin in food) on established rules of logic and evidence (e.g., prob- an affect scale (bad–good). Next, they were asked ability theory). The experiential system encodes to judge the degree of risk associated with a very reality in images, metaphors, and narratives to small exposure to the chemical, defined as an expo- which affective feelings have become attached. sure that is less than 1/100 of the exposure level To demonstrate the influence of the experiential that would begin to cause concern for a regulatory system, Denes-Raj and Epstein (1994) showed that, agency. Rationally, because exposure was so low, when offered a chance to win a prize by drawing a P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 1345 red jelly bean from an urn, subjects often elected to Unpublished follow-up studies showed that rep- draw from a bowl containing a greater absolute resentations of risk in the form of individual prob- number, but a smaller proportion, of red beans abilities of 10% or 20% led to relatively benign (e.g., 7 in 100) than from a bowl with fewer red images of one person, unlikely to harm anyone, beans but a better probability of winning (e.g., 1 whereas the ‘‘equivalent’’ frequentistic representa- in 10). For these individuals, images of 7 winning tions created frightening images of violent patients beans in the large bowl appeared to dominate the (example: ‘‘Some guy going crazy and killing image of 1 winning bean in the small bowl. someone’’). These affect-laden images likely We can characterize Epstein’s subjects as fol- induced greater perceptions of risk in response to lowing a mental strategy of ‘‘imaging the numera- the relative-frequency frames. tor’’ (i.e., the number of red beans) and neglecting Although frequency formats produce affect- the denominator (the number of beans in the laden imagery, story and narrative formats appear bowl). Consistent with the affect heuristic, images to do even better in that regard. Hendrickx et al. of winning beans convey positive affect that moti- (1989) found that warnings were more effective vates choice. when, rather than being presented in terms of rel- Although the jelly bean experiment may seem ative frequencies of harm, they were presented in frivolous, imaging the numerator brings affect to the form of vivid, affect-laden scenarios and anec- bear on judgments in ways that can be both non- dotes. Sanfey and Hastie (1998) found that com- intuitive and consequential. Slovic et al. (2000) pared with respondents given information in bar demonstrated this in a series of studies in which graphs or data tables, respondents given narrative experienced forensic psychologists and psychia- information more accurately estimated the perfor- trists were asked to judge the likelihood that a mance of a set of marathon runners. Furthermore, mental patient would commit an act of violence Pennington and Hastie (1993) found that jurors within 6 months after being discharged from the construct narrative-like summations of trial evi- hospital. An important finding was that clinicians dence to help them process their judgments of guilt who were given another expert’s assessment of a or innocence. patient’s risk of violence framed in terms of rela- Perhaps the biases in probability and frequency tive frequency (e.g., of every 100 patients similar judgment that have been attributed to the avail- to Mr. Jones, 10 are estimated to commit an act ability heuristic may be due, at least in part, to of violence to others ...’’) subsequently labeled affect. Availability may work not only through Mr. Jones as more dangerous than did clinicians ease of recall or imaginability, but because remem- who were shown a statistically ‘‘equivalent’’ risk bered and imagined images come tagged with expressed as a probability (e.g., ‘‘Patients similar affect. For example, Lichtenstein et al. (1978) to Mr. Jones are estimated to have a 10% chance invoked availability to explain why judged fre- of committing an act of violence to others’’). quencies of highly publicized causes of death Not surprisingly, when clinicians were told that (e.g., accidents, homicides, fires, tornadoes, and ‘‘20 out of every 100 patients similar to Mr. Jones cancer) were relatively overestimated and under- are estimated to commit an act of violence’’, 41% publicized causes (e.g., diabetes, stroke, asthma, would refuse to discharge the patient. But when tuberculosis) were underestimated. The highly another group of clinicians was given the risk as publicized causes appear to be more affectively ‘‘patients similar to Mr. Jones are estimated to charged, that is, more sensational, and this may have a 20% chance of committing an act of vio- account both for their prominence in the media lence’’, only 21% would refuse to discharge the and their relatively overestimated frequencies. patient. Similar results have been found by Yamagishi (1997), whose judges rated a disease 2.10. Further evidence that kills 1286 people out of every 10,000 as more dangerous than one that kills 24.14% of the The studies described above represent only a population. small fraction of the evidence that can be 1346 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 marshaled in support of the affect heuristic. twice as much to insure a beloved antique clock Although we have developed the affect heuristic (that no longer works and cannot be repaired) to explain findings from studies of judgment and against loss in shipment to a new city than to decision making (e.g., the inverse relationship insure a similar clock for which ‘‘one does not between perceived risks and benefits), one can find have any special feeling’’. In the event of loss, related proposals in the literature of marketing the insurance paid $100 in both cases. Similarly, and social cognition. For example, Wright (1975) Hsee and Menon (1999) found that students were proposed the ‘‘affect-referral heuristic’’ as a mech- more willing to buy a warranty on a newly pur- anism by which the remembered affect associated chased used car if it was a beautiful convertible with a product influences subsequent choice of than if it was an ordinary looking station wagon, that product (see also Pham, 1998). even if the expected repair expenses and cost of Attitudes have long been recognized as having a the warranty were held constant. strong evaluative component (see, e.g., Thurstone, Loewenstein et al. (2001) provide a particularly 1928 or Edwards, 1957). Pratkanis (1989) defined thorough review and analysis of research that sup- attitude as ‘‘a person’s evaluation of an object of ports their ‘‘risk-as-feelings hypothesis’’, a concept thought’’ (p. 72). He went on to propose that atti- that has much in common with the affect heuristic. tudes serve as heuristics, with positive attitudes They present evidence showing that emotional invoking a favoring strategy toward an object responses to risky situations, including feelings and negative attitudes creating disfavoring such as worry, fear, dread, or anxiety, often diverge response. More specifically, he defined the ‘‘atti- from cognitive evaluations and have a different and tude heuristic’’ as the use of the evaluative relation- sometimes greater impact on risk-taking behavior ship as a cue for assigning objects to a favorable than do cognitive evaluations. Among the factors class or an unfavorable class, thus leading to that appear to influence risk behaviors by acting approach or avoidance strategies appropriate to on feelings rather than cognitions are background the class. Pratkanis described numerous phenom- mood (e.g., Johnson and Tversky, 1983; Isen, ena that could be explained by the attitude heuris- 1993), the time interval between decisions and their tic, including halo effects not unlike the consistency outcomes (Loewenstein, 1987), vividness (Hend- described earlier between risk and benefit judg- rickx et al., 1989), and evolutionary preparedness. ments (Finucane et al., 2000). Loewenstein et al. invoke the evolutionary perspec- Other important work within the field of social tive to explain why people tend to react with little cognition includes studies by Fazio (1995) on the fear to certain types of objectively dangerous stim- accessibility of affect associated with attitudes uli that evolution has not prepared them for, such and by Schwarz and Clore (1988) on the role of as guns, hamburgers, automobiles, smoking, and affect as information. unsafe sex, even when they recognize the threat at Returning to the recent literature on judgment a cognitive level. Other types of stimuli, such as and decision making, Kahneman and colleagues caged spiders, snakes, or heights, which evolution have demonstrated that responses as diverse as may have prepared us to fear, evoke strong visceral willingness to pay for the provision of a public responses even when we recognize them, cogni- good (e.g., protection of an endangered species) tively, to be harmless. or a punitive damage award in a personal injury Individual differences in affective reactivity also lawsuit seems to be derived from attitudes based are informative. Damasio relied upon brain-dam- on emotion rather than on indicators of economic aged individuals, apparently lacking in the ability value (Kahneman and Ritov, 1994; Kahneman to associate emotion with anticipated outcomes, et al., 1998). to test his somatic-marker hypothesis. Similar Hsee and Kunreuther (2000) have demon- insensitivity to the emotional meaning of future strated that affect influences decisions about outcomes has been attributed to psychopathic whether or not to purchase insurance. In one individuals and used to explain their aberrant study, they found that people were willing to pay behaviors (Hare, 1965; Patrick, 1994). Using the P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 1347

Damasio card-selection task, Peters and Slovic Answer: To make them affectively more pleas- (2000) found that normal subjects who reported ing. One wonders whether the careers of John themselves to be highly reactive to negative events Denver, Sandra Dee, and Judy Garland would made fewer selections from decks with large losing have been as successful had they performed payoffs. Conversely, greater self-reported reactiv- under their real names—Henry Deutschendorf, ity to positive events was associated with a greater Alexandra Zuck, and Frances Gumm. Students number of selections from high-gain decks. Thus of onomastics, the science of names, have found individual differences in affective reactivity appear that the intellectual products of persons with to play a role in the learning and expression of less attractive names are judged to be of lower risk-taking preferences. quality (Harari and McDavid, 1973; Erwin and Calev, 1984) and some have even asserted that the affective quality of a presidential candi- 3. The downside of affect date’s name influences the candidate’s chances of being elected (Smith, 1997). Throughout this paper we have made many 2. Why do movies have background music? After claims for the affect heuristic, portraying it as the all, can’t we understand the events we are centerpiece of the experiential mode of thinking, watching and the dialog we are hearing without the dominant mode of survival during the evolution music? of the human species. But, like other heuristics that Answer: Music conveys affect and thus provide efficient and generally adaptive responses enhances meaning even for common human but occasionally lead us astray, reliance on affect interactions and events. can also deceive us. Indeed, if it was always optimal 3. Why are all the models in the mail-order catalog to follow our affective and experiential instincts, smiling? there would have been no need for the rational/ana- Answer: To link positive affect to the clothing lytic system of thinking to have evolved and become they are selling. so prominent in human affairs. 4. Why do packages of food products carry all There are two important ways that experien- those little blurbs such as ‘‘new’’, ‘‘natural’’, tial thinking misguides us. One results from the ‘‘improved’’, or ‘‘98% fat free’’? deliberate manipulation of our affective reactions Answer: These are ‘‘affective tags’’ that enhance by those who wish to control our behaviors. The the attractiveness of the product and increase other results from the natural limitations of the the likelihood it will be purchased, much as experiential system and the existence of stimuli in adding ‘‘Save 98%’’ increased the attractiveness our environment that are simply not amenable to of saving 150 lives. valid affective representation. Both types of prob- lems are discussed below. Clearly entertainers and marketers of consumer products have long been aware of the powerful 3.1. Manipulation of affect in our daily lives influence of affect. Perhaps no corporate entities have more zealously exploited consumers’ affective Given the importance of experiential thinking it sensitivities than the tobacco companies. A recent is not surprising to see many forms of deliberate ad for Kool Natural Lights, for example, repeats efforts being made to manipulate affect in order the word ‘‘natural’’ thirteen times in a single to influence our judgments and decisions. Con- half-page advertisement. The attractive images of sider, for example, some everyday questions about rugged cowboys and lush waterfalls associated with the world of entertainment and the world of con- cigarette ads are known to all of us. Indeed, affec- sumer marketing: tive associations between cigarettes and positive images may begin forming in children as young 1. Why do entertainers often change their as three years old (Fischer, 1991). As Epstein names? (1994) observes, ‘‘Cigarette advertising agencies 1348 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 and their clients are willing to bet millions of dol- 3.2. Failures of the experiential system: The case lars in advertising costs that the ... appeal of their of smoking messages to the experiential system will prevail over the verbal message of the Surgeon General Judgments and decisions can be faulty not only that smoking can endanger one’s life, an appeal because their affective components are manipula- directed at the rational system’’ (p. 712). Through ble, but also because they are subject to inherent the workings of the affect heuristic, as explicated biases of the experiential system. For example, by Finucane et al. (2000), we now have evidence the affective system seems designed to sensitize us suggesting that cigarette advertising designed to to small changes in our environment (e.g., the dif- increase the positive affect associated with smoking ference between 0 and 1 deaths) at the cost of mak- will quite likely depress perceptions of risk. The ing us less able to appreciate and respond factual (impassionate) appeal by the Surgeon Gen- appropriately to larger changes (e.g., the difference eral will likely have little effect. between 570 deaths and 670 deaths). Fetherston- Attempts at affective manipulation often work haugh et al. (1997) referred to this insensitivity as directly on language. Communicators desiring to ‘‘psychophysical numbing’’. change attitudes toward stigmatized technologies, Similar problems arise when the outcomes that for example, created ‘‘nukespeak’’ to extol the vir- we must evaluate change very slowly over time, are tues of ‘‘clean bombs’’ and ‘‘peacekeeper missiles’’, remote in time, or are visceral in nature. The irra- while promoters of nuclear power coined a new tionality of decisions to smoke cigarettes provides term for reactor accidents: ‘‘excursions’’. Geneti- dramatic examples of these types of failure (Slovic, cally modified food has been promoted as 2001). ‘‘enhanced’’ by proponents and ‘‘frankenfood’’ Despite the portrayal of beginning smokers as by opponents. ‘‘young economists’’ rationally weighing the risks Manipulation of attitudes and behavior by per- of smoking against the benefits when deciding suasive argumentation is often quite effective, but whether to initiate that activity (e.g., Viscusi, at least it tends to be recognized as an attempt to 1992), recent research paints a different picture. persuade. Manipulation of affect is no less power- This new account (Slovic, 2001) shows young smok- ful but is made more insidious by often taking ers acting experientially in the sense of giving little place without our awareness. It is unlikely that or no thought to risks or to the amount of smoking Hsee’s subjects recognized that what they were they will be doing. Instead, they go with the affective willing to pay for the used music dictionary was impulses of the moment, enjoying smoking as some- determined far more by the torn cover than thing new and exciting, a way to have fun with their by the more important dimension, number of friends. Even after becoming ‘‘regulars’’, the great entries. majority of smokers expect to stop soon, regardless Legal scholars such as Hanson and Kysar of how long they have been smoking, how many cig- (1999a,b), paying close attention to research on arettes they currently smoke per day, or how many affect and other judgment heuristics, have begun previous unsuccessful attempts they have experi- to speak out on the massive manipulation of con- enced. Only a fraction actually quit, despite many sumers by the packaging, marketing, and public attempts. The problem is nicotine addiction, a con- relations practices of manufacturers. Such manip- dition that young smokers recognize by name as a ulation, they argue, renders ineffective three pri- consequence of smoking but do not understand mary forms of legal control over dangerous experientially until they are caught up in it. products—warning requirements, product liability The process of becoming addicted appears to suits, and regulation of advertising. Hanson and begin surprisingly soon after one begins to smoke. Kysar (2001) point to the need for new regulatory Recent research indicates that adolescents begin to strategies that would take into account the full lia- show signs of nicotine dependence within days to bility of manufacturers who manipulate consumers weeks of the onset of occasional tobacco use (Di- into purchasing and using hazardous products. Franza et al., 2000). P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352 1349

Loewenstein (1999) explains the process of These disturbing findings underscore the dis- addiction as being governed by immensely power- tinction that behavioral decision theorists now ful visceral factors or cravings that, from an expe- make between decision utility and experience util- riential perspective, are very hard to anticipate and ity (Kahneman, 1997; Kahneman and Snell, 1992; appreciate: Loewenstein and Schkade, 1999). Utility predicted or expected at the time of decision often differs Unlike currently experienced visceral factors, greatly from the quality and intensity of the hedo- which have a disproportionate impact on behav- nic experience that actually occurs. ior, delayed visceral factors tend to be ignored or severely underweighted in decision making. Today’s pain, hunger, anger, etc. are palpable, 4. Conclusion but the same sensations anticipated in the future receive little weight. (p. 240) We hope that this rather selective and idiosyn- cratic tour through a me´lange of experiments The failure of the experiential system to protect and conjectures has conveyed the sense of excite- many young people from the lure of smoking is ment we feel toward the affect heuristic. This heu- nowhere more evident than in the responses to a ristic appears at once both wondrous and survey question that asks smokers: ‘‘If you had it frightening: wondrous in its speed, and subtlety, to do all over again, would you start smoking?’’ and sophistication, and its ability to ‘‘lubricate More than 85% of adult smokers and about 80% reason’’; frightening in its dependency upon con- of young smokers (ages 14–22) answer ‘‘no’’ (Slo- text and experience, allowing us to be led astray vic, 2001). Moreover, the more individuals per- or manipulated—inadvertently or intentionally— ceive themselves to be addicted, the more often silently and invisibly. they have tried to quit, the longer they have been It is sobering to contemplate how elusive mean- smoking, and the more cigarettes they are smoking ing is, due to its dependence upon affect. Thus the per day, the more likely they are to answer ‘‘no’’. forms of meaning that we take for granted and We can now address a central question posed upon which we justify immense effort and expense by Viscusi (1992):‘‘... at the time when individu- toward gathering and disseminating ‘‘meaningful’’ als initiate their smoking activity, do they under- information may be illusory. We cannot assume stand the consequences of their actions and make that an intelligent person can understand the rational decisions?’’ Viscusi went on to define the meaning of and properly act upon even the sim- appropriate test of rationality in terms of plest of numbers such as amounts of money, not ‘‘... whether individuals are incorporating the to mention more esoteric measures or statistics, available information about smoking risks and unless these numbers are infused with affect. are making sound decisions, given their own pref- Contemplating the workings of the affect heu- erences ...’’ (p. 11). ristic helps us appreciate Damasio’s (1994) conten- The data indicate that the answer to Viscusi’s tion that rationality is not only a product of the question is ‘‘no’’. Most beginning smokers lack analytical mind, but of the experiential mind as the experience to appreciate how their future selves well: will perceive the risks from smoking or how they will value the tradeoff between health and the need The strategies of human reason probably did not to smoke. This is a strong repudiation of the model develop, in either evolution or any single individ- of informed rational choice. It fits well with the find- ual, without the guiding force of the mechanisms ings indicating that smokers give little conscious of biological regulation, of which emotion and thought to risk when they begin to smoke. They feeling are notable expressions. Moreover, even appear to be lured into the behavior by the pros- after reasoning strategies become estab- pects of fun and excitement. Most begin to think lished ... their effective deployment probably of risk only after starting to smoke and gaining depends, to a considerable extent, on a continued what to them is new information about health risks. ability to experience feelings. (p. xii) 1350 P. Slovic et al. / European Journal of Operational Research 177 (2007) 1333–1352

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