Task formats and ambiguity aversion

This paper proposes that task format (choosing or rejecting) moderates the effect of ambiguity aversion. Specifically, an ambiguous option is more attractive in a choosing task than in a rejecting task compared with a risky option. The author performed three experiments to test the propositions. In the first experiment, participants showed less ambiguity aversion when they had to choose a preferred option (risky or ambiguous) compared with when they had to reject an option they preferred less. In the second experiment with a monetary incentive, participants had to form a cash‐equivalent estimate for both a risky gamble and an ambiguous gamble in a traditional Ellsberg scenario. The ambiguous option emerged as more attractive than the risky option in the choosing task compared with the rejecting task. The third experiment showed that the participants' decision rationale mediated the effect of the task format on choice. These three experiments support the proposition that task formats moderate the effect of ambiguity aversion. On the basis of the findings, the author provides suggestions for practice and further research. Copyright © 2010 John Wiley & Sons, Ltd.     

Impact of regulatory focus on ambiguity aversion

Although prior research has shown that some people prefer a risky to an ambiguous option, this study further proposes that people's regulatory focus (promotion vs. prevention) might influence their ambiguity aversion. Three experiments have tested whether people with promotion focus showed less ambiguity aversion than those with prevention focus: The first experiment revealed that, compared with chronically promotion‐focused individuals, prevention‐focused subjects preferred a risky to an ambiguous option. In the second experiment, priming of the subjects' goal orientations led to similar results. Experiment 3 demonstrated that participants showed less ambiguity aversion for the expected performance of an investment product representative of promotion (e.g., a stock fund) rather than one representative of prevention (e.g., a bond fund). In other words, people showed less preference for a bond fund when the probability distribution of its expected performance was unknown than when it was known, whereas they showed less preference difference between known and unknown probability distributions for the expected performance of a stock fund. This study has integrated research pertaining to regulatory focus and ambiguity aversion, and the results have confirmed that the impact of regulatory focus on ambiguity aversion is robust across different methods and decision tasks. Copyright © 2010 John Wiley & Sons, Ltd.     

When do peers influence adolescent males' risk taking? Examining decision making under conditions of risk and ambiguity

Risk taking is highly prevalent among adolescent males, and a range of studies have shown that decisions become riskier if a peer is present. However, previous studies have typically provided participants with explicit probabilities of risk in each situation. This does not accurately reflect adolescents' real‐world risk taking, where decisions are made in ambiguous situations alongside their peers. Aiming for a more ecologically valid design, the present experiment manipulated situational ambiguity and examined its interplay with group decision making and developmental factors. Adolescent males (N = 202) aged 12–15 completed a “Wheel of Fortune” task and then self‐reported their score, presenting an opportunity to cheat as a measure of antisocial risk taking. As predicted, adolescents were more likely to take risks when probabilities were ambiguous rather than explicit. Further, higher levels of gambling choices were made by groups in ambiguous, but not risk situations. Age significantly predicted gambling in ambiguous conditions, whereas developmental dispositions (risk perception, reward sensitivity, and inhibitory control) did not play a role. Findings provide an insight into the social and situational conditions under which adolescent males engage in reckless behavior.     

Attributions for ambiguity in a treatment-decision context can create ambiguity aversion or seeking

The phenomenon of ambiguity aversion suggests that people prefer options that offer precisely rather than imprecisely known chances of success. However, past work on people's responses to ambiguity in health treatment contexts found ambiguity seeking rather than aversion. The present work addressed whether such findings reflected a broad tendency for ambiguity seeking in health treatment contexts or whether specific attributions for ambiguity play a substantial role. In three studies, people choose between two treatment options that involved similar underlying probabilities, except that the probabilities for one option involved ambiguity. The attributions offered for the ambiguity played an important role in the results. For example, when the range of probabilities associated with an ambiguous treatment was attributed to the fact that different studies yield different results, participants tended to show ambiguity aversion or indifference. However, when the range was attributed to something that participants could control (e.g., regular application of a cream) or something about which they were overoptimistic (e.g., their immune system function), participants tended to show ambiguity seeking. Health professionals should be mindful of how people will interpret and use information about ambiguity when choosing among treatments.     

Ambiguity attitudes in qualitative contexts: The role of prior beliefs

Most studies of ambiguity aversion rely on experimental paradigms involving monetary bets. Thus, the extent to which ambiguity aversion occurs outside of such contexts is much less understood, particularly when the situation cannot easily be reduced to numerical terms. The present work seeks to understand whether people prefer to avoid ambiguous decisions in a variety of different qualitative domains (e.g., work, family, love, friendship, exercise, study, and health), and, if so, to determine the role played by prior beliefs in those domains. Across three studies, we presented participants with 24 vignettes and measured the degree to which they preferred risk to ambiguity in each. We also asked them for their prior probability estimates about the likely outcomes in the ambiguous events. Ambiguity aversion was observed in the vast majority of vignettes, but at different magnitudes. It was predicted by whether the vignette involved gain or loss as well as by people's prior beliefs; however, the heterogeneity between people meant that the role of prior beliefs was only evident in an individual-level analysis (i.e., not at the group level). Our results suggest that the desire to avoid ambiguity occurs in a wide variety of qualitative contexts but to different degrees for different people and may be partially driven by unfavorable prior estimates of the likely outcomes of the ambiguous events.     

How Well Do We Know Our Inner Daredevil? Probing the Relationship Between Self‐Report and Behavioral Measures of Risk Taking

To measure a person's risk‐taking tendency, research has relied interchangeably on self‐report scales (e.g., “Indicate your likelihood of engaging in the risky behavior”) and more direct measures, such as behavioral tasks (e.g., “Do you accept or reject the risky option?”). It is currently unclear, however, how the two approaches map upon each other. We examined the relationship between self‐report likelihood ratings for risky choice in a monetary gamble task and actual choice, and tested how the relationship is affected by task ambiguity (i.e., when part of the information about risks and benefits is missing) and age. Five hundred participants (aged 19–85 years) were presented with 27 gambles, either in an unambiguous or an ambiguous condition. In a likelihood rating task, participants rated for each gamble the likelihood that they would accept it. In a separate choice task, they were asked to either accept or reject each gamble. Analyses using a signal‐detection approach showed that people's likelihood ratings discriminated between accept and reject cases in their choices rather well. However, task ambiguity weakened the association between likelihood ratings and choice. Further, older adults' likelihood ratings anticipated their choices more poorly than younger adults'. We discuss implications of these findings for existing approaches to the study of risk‐taking propensity, which have often relied on self‐reported risk tendency for ambiguous activities. Copyright © 2016 John Wiley & Sons, Ltd.     

不确定性容忍度对模糊决策中决策偏好的影响及其情景依赖性*

研究以Ellsberg选瓶任务为决策材料,探讨了不同任务特征下个体不确定性容忍度对模糊决策中决策偏好的影响。结果发现,获益情景下:高概率时高、低容忍度个体对模糊选项的选择无显著差异,均偏好模糊规避;中概率时低容忍度个体比高容忍度个体表现出更低程度的模糊规避,前者倾向于模糊中立,后者倾向于模糊规避;低概率时两者对模糊选项的选择无显著差异,均倾向于模糊中立。损失情景下:高概率时两者对模糊选项的选择无显著差异,均倾向于模糊寻求;中概率时低容忍度比高容忍度个体更偏好模糊寻求,前者倾向于模糊寻求,后者倾向于模糊中立;低概率时两者对模糊选项的选择无显著差异,均倾向于模糊规避。这表明,不确定性容忍度对模糊决策偏好产生作用,但这种作用会受到损益概率和损益结果的影响,具有情景依赖性。     

Is luck on my side? Optimism,pessimism, and ambiguity aversion

The influences of optimism and pessimism on ambiguity aversion were investigated in two tasks that manipulated the presence or absence of a potentially competitive experimenter. A total of 112 participants chose which option—ambiguous or known-risk—they preferred in the two slightly differing Ellsberg urns tasks. Optimism was measured using the Extended Life Orientation Test (ELOT). Highly optimistic people showed significantly less ambiguity aversion than less optimistic people when information was given that the number of balls was randomly determined. This pattern was present but less pronounced in the condition when the composition of the ambiguous urn could be interpreted as being influenced (rigged) by the experimenter. Pessimism was uninfluential. Perceptions of the situation, especially the degree of trust in the experimenter, were significantly influenced by the participants' optimism. People who do not have highly optimistic personalities tend to shy away from choosing ambiguous options. When ambiguity is clear, and trust issues are removed, people's optimistic outlook influences their degree of ambiguity aversion and thus their decisions.     

Practice makes perfect: Training the interpretation of emotional ambiguity

The interpretation of emotionally ambiguous words, sentences, or scenarios can be altered through training procedures that are collectively called cognitive bias modification for interpretation (CBM-I). In three experiments, we systematically manipulated the nature of the training in order to discriminate between emotional priming and ambiguity resolution accounts of training effects. In Experiment 1 participants completed word fragments that were consistently related to either a negative or benign interpretation of an ambiguous sentence. In a subsequent semantic priming task they demonstrated an interpretation bias, in that they were faster to identify relatedness of targets that were associated with the training-congruent meaning of an emotionally ambiguous homograph. We then manipulated the training sentences to show that interpretation bias was eliminated when participants simply completed valenced word fragments following unrelated sentences (Experiment 2), or completed fragments that were related to emotional but unambiguous sentences (Experiment 3). Only when participants were required to actively resolve emotionally ambiguous sentences during training did changes in interpretation emerge at test. Findings suggest that CBM-I achieves its effects by altering a production rule that aids the selection of meaning from emotionally ambiguous alternatives, in line with an ambiguity resolution account.     

模糊决策的情境依赖性

实验1采用艾尔斯伯格悖论的研究范式,探究被试对模糊的厌恶倾向以及在决策过程中所采用的决策策略。结果发现：被试对确定选项和模糊选项的选择存在差异;在肯定形式下倾向于确定选项,而在否定形式下则倾向于模糊选项,采用了利益最大化策略。实验2采用艾尔斯伯格悖论的变式,通过操纵概率和任务类型,发现：模糊决策具有情境依赖性,并非任何情况下个体都厌恶模糊。当风险选项不能满足自己的需要,即获胜机率比较小时,人们会偏向模糊选项。     

Resolving syntactic category ambiguity: An eye-movement analysis

In two experiments, participants' eye movements were monitored as they read sentences containing biased syntactic category ambiguous words with either distinct (e.g., duck) or related (e.g., burn) meanings or unambiguous control words. In Experiment 1, prior context was consistent with either the dominant or subordinate interpretation of the ambiguous word. The subordinate bias effect was absent for the ambiguous words in gaze duration measures. However, effects of ambiguity did emerge in other measures for the ambiguous words preceded by context supporting the subordinate interpretation. In Experiment 2, context preceding the target words was neutral. Ambiguity effects only arose when posttarget context was consistent with the subordinate interpretation of the ambiguous words, indicating that readers initially selected the dominant interpretation. Results support immediate theories of syntactic category ambiguity resolution, but also suggest that recovery from misanalysis of syntactic category ambiguity is more difficult than for lexical-semantic ambiguity in which alternate interpretations do not cross syntactic category.     

模糊规避的形成机制：基于可评价性假设的视角

模糊规避是指在相同奖赏的情况下,决策者会力图规避从主观上判断具有模糊概率的事件而偏好具有相同精确概率的事件。本研究使用同时评价、单独评价的研究范式从随机事件和自然事件两个领域来探讨模糊规避的形成机制。研究结果表明,当风险事件和模糊事件同时评价时,个体倾向于模糊规避;当风险事件和模糊事件单独评价时,模糊规避会消失。     

Different Attentional Patterns for Regret and Disappointment: An Eye‐tracking Study

The unfavorable comparison between the obtained and expected outcomes of our choices may elicit disappointment. When the comparison is made with the outcome of alternative actions, emotions like regret can serve as a learning signal. Previous work showed that both anticipated disappointment and regret influence decisions. In addition, experienced regret is associated with higher emotional responses than disappointment. Yet it is not clear whether this amplification is due to additive effects of disappointment and regret when the outcomes of alternative actions are available, or whether it reflects the learning feature of regret signals. In this perspective, we used eye‐tracking to measure the visual pattern of information acquisition in a probabilistic lottery task. In the partial feedback condition, only the outcome of the chosen lottery was revealed, while in the complete feedback condition, participants could compare their outcome with that of the non‐chosen lottery, giving them the opportunity to experience regret. During the decision phase, visual patterns of information acquisition were consistent with the assessment of anticipated regret, in addition to a clear assessment of lotteries' expected values. During the feedback phase, subjective ratings and eye‐tracking results confirmed that participants compared their outcome with the outcome of the non‐chosen lottery in the complete feedback condition, particularly after a loss, and ignored the non‐realized outcome of the chosen option. Moreover, participants who made more visual saccades consistent with counterfactual comparisons during the feedback period anticipated regret more in their decisions. These results are consistent with the proposed adaptive function of regret. © 2016 The Authors Journal of Behavioral Decision Making Published by John Wiley & Sons Ltd.     

Modelling the effects of semantic ambiguity in word recognition

Most words in English are ambiguous between different interpretations; words can mean different things in different contexts. We investigate the implications of different types of semantic ambiguity for connectionist models of word recognition. We present a model in which there is competition to activate distributed semantic representations. The model performs well on the task of retrieving the different meanings of ambiguous words, and is able to simulate data reported by Rodd, Gaskell, and Marslen-Wilson [J. Mem. Lang. 46 (2002) 245] on how semantic ambiguity affects lexical decision performance. In particular, the network shows a disadvantage for words with multiple unrelated meanings (e.g., bark) that coexists with a benefit for words with multiple related word senses (e.g., twist). The ambiguity disadvantage arises because of interference between the different meanings, while the sense benefit arises because of differences in the structure of the attractor basins formed during learning. Words with few senses develop deep, narrow attractor basins, while words with many senses develop shallow, broad basins. We conclude that the mental representations of word meanings can be modelled as stable states within a high-dimensional semantic space, and that variations in the meanings of words shape the landscape of this space.     

Effects of referential ambiguity,time constraints and addressee orientation on the production of morphologically complex words

In five experiments, participants were asked to describe unambiguously a target picture in a picture–picture paradigm. In the same-category condition, target (e.g., water bucket) and distractor picture (e.g., ice bucket) had identical names when their preferred, morphologically simple, name was used (e.g., bucket). The ensuing lexical ambiguity could be resolved by compound use (e.g., water bucket). Simple names sufficed as means of specification in other conditions, with distractors identical to the target, completely unrelated, or geometric figures. With standard timing parameters, participants produced mainly ambiguous answers in Experiment 1. An increase in available processing time hardly improved unambiguous responding (Experiment 2). A referential communication instruction (Experiment 3) increased the number of compound responses considerably, but morphologically simple answers still prevailed. Unambiguous responses outweighed ambiguous ones in Experiment 4, when timing parameters were further relaxed. Finally, the requirement to name both objects resulted in a nearly perfect ambiguity resolution (Experiment 5). Together, the results showed that speakers overcome lexical ambiguity only when time permits, when an addressee perspective is given and, most importantly, when their own speech overtly signals the ambiguity.     

Revisions and Regret: The Cost of Changing your Mind

Decision reversals often imply improved decisions. Yet, people show a strong resistance against changing their minds. These are well‐established findings, which suggest that changed decisions carry a subjective cost, perhaps by being more strongly regretted. Three studies were conducted to explore participants' regret when making reversible decisions and to test the hypothesis that changing one's mind will increase post‐outcome regret. The first two studies employed the Ultimatum game and the Trust game. The third study used a variant of the Monty Hall problem. All games were conducted by individual participants playing interactively against a computer. The outcomes were designed to capture a common characteristic of real‐life decisions: they varied from rather negative to fairly positive, and for every outcome, it was possible to imagine both more and less profitable outcomes. In all experiments, those who changed their minds reported much stronger post‐outcome regret than those who did not change, even if the final outcomes were equally good (Experiments 2 and 3) or better (Experiment 1).This finding was not because of individual differences with respect to gender, tendency to regret, or tendency to maximize. Previous studies have found that those who change from a correct to wrong option regret more than those who select a wrong option directly. This study indicates that this finding is a special case of a more general phenomenon: changing one's mind seems to come with a cost, even when one ends up with favorable outcomes. Copyright © 2011 John Wiley & Sons, Ltd.     

Creating shared reality about ambiguous sexual harassment: The role of stimulus ambiguity in audience-tuning effects on memory

By tuning messages about ambiguous information to their audience's attitude, communicators can reduce uncertainty and form audience-congruent memories. This effect has been conceptualized as the creation of shared reality with the audience. We applied this approach to representations of ambiguous antecedents of sexual harassment and examined whether the effect depends on the event's perceived ambiguity. Participants read a testimony about a supervisor's ambiguous behaviors toward a female employee and described the behaviors to an audience who had previously evaluated him positively or negatively. We manipulated perceived ambiguity of the testimony by including or omitting information about eventual, clear-cut harassment (known vs. unknown outcome). As predicted, participants aligned their messages and memory with their audience's evaluation only in the unknown-outcome condition, where epistemic uncertainty was higher. The findings highlight the role of epistemic needs in the communicative creation of a shared reality about a ubiquitous social situation with potentially harmful outcomes.     

Verbalization of Decision Strategies in Multiple‐Cue Probabilistic Inference

In multiple‐cue probabilistic inference, people choose between alternatives based on several cues, each of which is differentially associated with an alternative's overall value. Various strategies have been proposed for probabilistic inference (e.g., weighted additive, tally, and take‐the‐best). These strategies differ in how many cue values they require to enact and in how they weight each cue. Do decision makers actually use any of these strategies? Ways to investigate this question include analyzing people's choices and the cues that they reveal. However, different strategies often predict the same decisions, and search behavior says nothing about whether or how people use the information that they acquire. In this research, we attempt to elucidate which strategies participants use in a multiple‐cue probabilistic inference task by examining verbal protocols, a high‐density source of process data. The promise of verbal data is in their utility for testing detailed information processing models. To that end, we apply protocol analysis in conjunction with computational simulations. We find converging evidence across outcome measures, search measures, and verbal reports that most participants use simplifying heuristics, namely take‐the‐best. Copyright © 2015 John Wiley & Sons, Ltd.