Eric R. Stone

Foreground:background salience: Explaining the effects of graphical displays on risk avoidance

Abstract The purpose of this research was to determine the mechanisms underlying the graphical effect identified by Stone, Yates, and Parker (1997) , in which graphical formats for conveying risk information are more effective than numerical formats for increasing risk-avoidant behavior. Two experiments tested whether this graphical effect occurred because the graphical formats used by Stone et al. highlighted the number of people harmed by the focal hazard, causing the decisions to be based mainly on the number of people harmed (which we label the “foreground”) at the expense of the total number of people at risk of harm (which we call the “background”). Specifically, two graphical formats were developed that displayed pictorially both the number of people harmed and the total number at risk, and use of these display formats eliminated the graphical effect. We thus propose that the previously discussed graphical effect was in fact a manifestation of a more general foreground:background salience effect, whereby displays that highlight the number of people harmed at the expense of the total number of people at risk of harm lead to greater risk avoidance. Theoretical and practical implications are discussed.

The Greater Ability of Graphical Versus Numerical Displays to Increase Risk Avoidance Involves a Common Mechanism

By displaying a risk reduction of 50% graphically rather than numerically, Stone, Yates, and Parker significantly increased professed risk-avoidant behavior. The current experiments replicated this effect at various risk ratios. Specifically, participants were willing to spend more money to reduce a risk when the risk information was displayed by asterisks rather than by numbers for risk-reduction ratios ranging from 3% to 97%. Transforming the amount participants were willing to spend to logarithms significantly improved a linear fit to the data, suggesting that participants convert this variable within the decision-making process. Moreover, a log-linear model affords an exceptional fit to both the graphical and numerical data, suggesting that a graphical presentation elicits the same decision-making mechanism as does the numerical display. In addition, the data also suggest that each person removed from harm is weighted more by some additional factor in the graphical compared to the numerical presentations.

A Social Values Analysis of Self–Other Differences in Decision Making Involving Risk

Three experiments tested our social values analysis of self–other differences in decision making under risk. In Experiment 1, we showed that people make riskier decisions for others in domains where risk taking is valued but not in those where risk is not valued. Experiment 2 documented that it is considered more inappropriate to make a risk-averse decision for another person than for oneself in situations where risk is valued. Experiment 3 showed that self–other differences in decision making occur even when there are no self–other differences in prediction and for decisions made for a typical student as well as for a friend. We use these results to argue that decision making for others is based predominantly on the perceived value placed on risk, leading to a norm for how to decide for others in situations where such a social value exists.

The psychology of intelligence analysis: Drivers of prediction accuracy in world politics

This article extends psychological methods and concepts into a domain that is as profoundly consequential as it is poorly understood: intelligence analysis. We report findings from a geopolitical forecasting tournament that assessed the accuracy of more than 150,000 forecasts of 743 participants on 199 events occurring over 2 years. Participants were above average in intelligence and political knowledge relative to the general population. Individual differences in performance emerged, and forecasting skills were surprisingly consistent over time. Key predictors were (a) dispositional variables of cognitive ability, political knowledge, and open-mindedness; (b) situational variables of training in probabilistic reasoning and participation in collaborative teams that shared information and discussed rationales (Mellers, Ungar, et al., 2014); and (c) behavioral variables of deliberation time and frequency of belief updating. We developed a profile of the best forecasters; they were better at inductive reasoning, pattern detection, cognitive flexibility, and open-mindedness. They had greater understanding of geopolitics, training in probabilistic reasoning, and opportunities to succeed in cognitively enriched team environments. Last but not least, they viewed forecasting as a skill that required deliberate practice, sustained effort, and constant monitoring of current affairs.

Depressive Cognition: A Test of Depressive Realism Versus Negativity Using General Knowledge Questions

Abstract This research is an examination of whether cognition in depressed individuals incorporates a realistic view of the world or a general tendency toward negativity. Participants provided two types of probability judgments of the likelihood that they correctly answered general knowledge questions: the probability that they correctly answered each of the individual questions and an aggregate judgment, after completing the questionnaire, of the percentage of all the questions they thought they had correctly answered. These tasks generally elicit overconfidence and accuracy in nondepressives. In accord with theories of both depressive realism and general negativity, in their item-by-item assessments of their answers to the individual questions, depressed participants demonstrated less overconfidence than nondepressed participants. In accord with the theory of general negativity but not with the theory of depressive realism, however, depressed participants demonstrated underconfidence in their aggregate judgments. The implications of these findings on theories of depressive cognition are discussed.

Children’s decision making: the effects of training, reinforcement, and memory aids

Abstract Previous research on children’s decision making [Cogn. Dev. 6 (1991a) 77] has found that, unlike older children and adults, young children are frequently unable to eliminate an alternative as soon as it is clear that it is unsuitable. More precisely, young children have difficulty ignoring irrelevant information and attending to relevant information when examining alternatives. The present study explored whether children’s tendency to ignore relevant information is due to the saliency of that information, the child’s lack of motivation, or memory limitations of the child. To test these hypotheses, 197 second and fifth graders were divided into four groups: a training group designed to overcome saliency concerns, a reinforcement group designed to overcome motivation problems, a marking group designed to overcome memory limitations, and a control group. Children in the training and reinforcement groups examined less irrelevant information than did children in the control group; however, marking unsuitable alternatives did not improve children’s performance. This left the role of memory unclear. Additionally, verbal skill level was related to the number of irrelevant items examined for all children, but accounted for a minimal amount of variance.

Distilling the Wisdom of Crowds: Prediction Markets vs. Prediction Polls

We report the results of the first large-scale, long-term, experimental test between two crowd sourcing methods – prediction markets and prediction polls. More than 2,400 participants made forecasts on 261 events over two seasons of a geopolitical prediction tournament. Some forecasters traded in a continuous double auction market and were ranked based on earnings. Others submitted probability judgments, independently or in teams, and were ranked based on Brier scores. In both seasons of the tournament, last day prices from the prediction market were more accurate than the simple mean of forecasts from prediction polls. However, team prediction polls outperformed prediction markets when poll forecasts were aggregated with algorithms using temporal decay, performance weighting and recalibration. The biggest advantage of prediction polls occurred at the start of long-duration questions. Prediction polls with proper scoring, algorithmic aggregation and teaming offer an attractive alternative to prediction markets for distilling the wisdom of crowds.

The effect of communication design and recipients’ numeracy on responses to UXO risk

Risk communications aim to affect recipients’ understanding of specific risks, their trust and liking of the materials, affective responses, and associated behaviors. We developed communications about the number of construction workers expected to get hurt if building were permitted at the former Fort Ord weapons training site in California, despite its contamination with unexploded ordnance (UXO). We created eight versions, which presented text only or bar graph with text, the numerator of the risk (the number of workers expected to be hurt) with or without emphasis on the denominator (the total number of workers), and uncertainty information (the probability that different numbers of workers would be hurt) or not. Recipients varied in numeracy. We examined the effect of these communication features on recipients’ (1) understanding, (2) trust and liking of the materials, (3) affective responses, and (4) support for construction and for construction workers if construction were to be implemented. Low-numerate individuals showed less understanding across all versions of the communication, yet preferred graph-with-text displays relatively more than text-only displays as compared to high-numerate individuals. Emphasizing the denominator increased understanding of text-only displays but decreased support for construction and construction workers for all communication versions. Moreover, recipients were more supportive of construction and construction workers after receiving text-only displays without uncertainty information or graph-with-text displays with uncertainty information, seemingly due to communications with those features being trusted and liked more. We discuss the implications for communicating risks in general and for communicating UXO-related risks to the community surrounding Fort Ord.

Effects of numerical versus foreground-only icon displays on understanding of risk magnitudes

The aim of this work is to advance knowledge of how to measure gist and verbatim understanding of risk magnitude information and to apply this knowledge to address whether graphics that focus on the number of people affected (the numerator of the risk ratio, i.e., the foreground) are effective displays for increasing (a) understanding of absolute and relative risk magnitudes and (b) risk avoidance. In 2 experiments, the authors examined the effects of a graphical display that used icons to represent the foreground information on measures of understanding (Experiments 1 and 2) and on perceived risk, affect, and risk aversion (Experiment 2). Consistent with prior findings, this foreground-only graphical display increased perceived risk and risk aversion; however, it also led to decreased understanding of absolute (although not relative) risk magnitudes. Methodologically, this work shows the importance of distinguishing understanding of absolute risk from understanding of relative risk magnitudes, and the need to assess gist knowledge of both types of risk. Substantively, this work shows that although using foreground-only graphical displays is an appealing risk communication strategy to increase risk aversion, doing so comes at the cost of decreased understanding of absolute risk magnitudes.

Communicating Quantitative Information About Unexploded Ordnance Risks to the Public

Military base closures have left 600,000 acres of U.S. land contaminated with unexploded ordnance (UXO). Recent research has demonstrated a method for quantifying the probability of residual UXO harming future land users. Here, we explore how a community neighboring a closed, UXO-contaminated military base responds to the probabilistic risk information this method produces. We explore how probabilistic information affects their risk understanding, risk management preferences, risk perceptions, and worry. We test eight different communication formats employing varying combinations of textual risk descriptions, comparative risk information, stacked bar graphs illustrating the proportion of future land users at risk, and textual summaries and/or graphical histograms presenting uncertainty. We find that stacked bar graphs double the odds of correctly reporting the probability of harm and decrease the perceived risk, compared to textual descriptions. Providing histograms or summary uncertainty information decreases the odds of correctly reporting the probability of harm by about one-half, compared to communications without uncertainty information. We also find that risk communication formats do not alter risk management preferences. We recommend that as EPA reevaluates its UXO risk management policies in the coming year, the agency shift to quantitative rather than its current qualitative approach to assessing and communicating UXO risks.