To Err

Kevin Lewis

May 19, 2020

What You See Is All There Is
Benjamin Enke
Quarterly Journal of Economics, forthcoming


News reports and communication are inherently constrained by space, time, and attention. As a result, news sources often condition the decision of whether to share a piece of information on the similarity between the signal and the prior belief of the audience, which generates a sample selection problem. This paper experimentally studies how people form beliefs in these contexts, in particular the mechanisms behind errors in statistical reasoning. I document that a substantial fraction of experimental participants follows a simple "what you see is all there is" heuristic, according to which participants exclusively take into account information that is right in front of them, and directly use the sample mean to estimate the population mean. A series of treatments aimed at identifying mechanisms suggests that for many participants unobserved signals do not even come to mind. I provide causal evidence that the frequency of such incorrect mental models is a function of the computational complexity of the decision problem. These results point to the context-dependence of what comes to mind and the resulting errors in belief updating.

An inch away from being mentally tough: Performance bias in ratings of mental toughness
Benjamin Schellenberg & Patrick Gaudreau
Sport, Exercise, and Performance Psychology, forthcoming


Are assessments of an athlete's mental toughness influenced by how that athlete performs in a single moment in a game? We conducted 3 experimental studies to address this question and conclude that the answer is yes. In each study, sports fans (total N = 1,097) read vignettes that depicted a mentally tough basketball player, either by describing the player as having many mentally tough attributes (Study 1) or by stating that the player had been identified as being mentally tough by an expert sport psychologist (Studies 2 and 3). Participants then read that the player was about to take a championship-winning shot and were randomly assigned to learn that the shot had been either successful or unsuccessful. Moreover, in Studies 1 and 2, participants learned that the outcome had been either decisive (i.e., a "perfect swish" or an "air ball") or indecisive (i.e., the ball hitting the backboard, then the rim, and, eventually, either going or not going into the basket). In each study, despite learning that the athlete was very mentally tough, participants' mental toughness ratings depended on whether or not the shot was successful. Ratings were also sensitive to the way in which an outcome was attained: Ratings decreased in a linear pattern, with the highest ratings after a decisive success, followed by an indecisive success, and an indecisive failure, and the lowest ratings after a decisive failure. This research supports the criticism that evaluations of mental toughness are distorted by how an athlete performs in a single moment.

Decisional autonomy undermines advisees' judgments of experts in medicine and in life
Samantha Kassirer, Emma Levine & Celia Gaertig
Proceedings of the National Academy of Sciences, forthcoming


Over the past several decades, the United States medical system has increasingly prioritized patient autonomy. Physicians routinely encourage patients to come to their own decisions about their medical care rather than providing patients with clearer yet more paternalistic advice. Although political theorists, bioethicists, and philosophers generally see this as a positive trend, the present research examines the important question of how patients and advisees in general react to full decisional autonomy when making difficult decisions under uncertainty. Across six experiments (N = 3,867), we find that advisers who give advisees decisional autonomy rather than offering paternalistic advice are judged to be less competent and less helpful. As a result, advisees are less likely to return to and recommend these advisers and pay them lower wages. Importantly, we also demonstrate that advisers do not anticipate these effects. We document these results both inside and outside the medical domain, suggesting that the preference for paternalism is not unique to medicine but rather is a feature of situations in which there are adviser-advisee asymmetries in expertise. We find that the preference for paternalism holds when advice is solicited or unsolicited, when both paternalism and autonomy are accompanied by expert guidance, and it persists both before and after the outcomes of paternalistic advice are realized. Lastly, we see that the preference for paternalism only occurs when decision makers perceive their decision to be difficult. These results challenge the benefits of recently adopted practices in medical decision making that prioritize full decisional autonomy.

Seeing isn't necessarily believing: Misleading contextual information influences perceptual-cognitive bias in radiologists
Bradley Fawver et al.
Journal of Experimental Psychology: Applied, forthcoming


A substantial number of medical errors in radiology are attributed to failures of perception or decision making, although it is believed that experience (or expertise) might buffer diagnosticians from some types of perceptual-cognitive bias. We examined how the quality of contextual information influences decision making and how underlying perceptual-cognitive processes change as a function of experience and diagnostic accuracy. Twenty-one radiologists dictated their findings on 16 deidentified musculoskeletal radiographic cases while wearing a mobile-eye tracking system. Patient histories were mismatched on a subset of cases to be miscued relative to the correct diagnosis. Experienced radiologists outperformed less-experienced participants, but no systematic differences in gaze behaviors emerged between groups. Miscued case notes increased perceptual-cognitive bias in both groups, resulting in an approximate 40% decrease in diagnostic accuracy. Most errors were judgment errors, meaning participants visually fixated on the abnormality for longer than a second yet still failed to make the correct diagnosis. Findings suggest a physician's confidence in their diagnosis might be misplaced after spending insufficient time extracting relevant information from key areas of the visual display, or when decisions are based primarily on a priori expectations derived from patient histories.

Evidence of vulnerability to decision bias in expert field scientists
Cristina Wilson, Thomas Shipley & Alexandra Davatzes
Applied Cognitive Psychology, forthcoming


Previous research demonstrates that domain experts, like ordinary participant populations, are vulnerable to decision bias. Here, we examine susceptibility to bias amongst expert field scientists. Field scientists operate in less predictable environments than other experts, and feedback on the consequences of their decisions is often unclear or delayed. Thus, field scientists are a population where the findings of scientific research may be particularly vulnerable to bias. In this study, susceptibility to optimism, hindsight, and framing bias was evaluated in a group of expert field geologists using descriptive decision scenarios. Experts showed susceptibility to all three biases, and susceptibility was not influenced by years of science practice. We found no evidence that participants' vulnerability to one bias was related to their vulnerability to another bias. Our findings are broadly consistent with previous research on expertise and decision bias, demonstrating that no expert, regardless their domain experience, is immune to bias.

Self-regulatory aspects of bullshitting and bullshit detection
John Petrocelli, Haley Watson & Edward Hirt
Social Psychology, forthcoming


Two experiments investigate the role of self-regulatory resources in bullshitting behavior (i.e., communicating with little to no regard for evidence, established knowledge, or truth; Frankfurt, 1986; Petrocelli, 2018a), and receptivity and sensitivity to bullshit. It is hypothesized that evidence-based communication and bullshit detection require motivation and considerably greater self-regulatory resources relative to bullshitting and insensitivity to bullshit. In Experiment 1 (N = 210) and Experiment 2 (N = 214), participants refrained from bullshitting only when they possessed adequate self-regulatory resources and expected to be held accountable for their communicative contributions. Results of both experiments also suggest that people are more receptive to bullshit, and less sensitive to detecting bullshit, under conditions in which they possess relatively few self-regulatory resources.

Examining the roles of Intuition and Gender in Magical Beliefs
Sarah Ward & Laura King
Journal of Research in Personality, forthcoming


Four studies explored gender differences in magical beliefs, specifically examining whether reliance on intuition accounts for women's higher magical beliefs (vs. men's). In Studies 1a and 1b (N's= 489, 1119), women's higher magical beliefs were accounted for by measures of reliance on intuition. Study 2 (N=533) demonstrated that an intuition induction heightened men's magical beliefs (vs. control group), but not women's. In Study 3 (N=404), women - but not men - exhibited more suboptimal choices in a lottery task after imagining that a dream told them to do so. These studies suggest that reliance on intuition helps account for women's higher magical beliefs.

The Gender Gap in Housing Returns
Paul Goldsmith-Pinkham & Kelly Shue
NBER Working Paper, March 2020


Housing wealth represents the dominant form of savings for American households. Using detailed data on housing transactions across the United States since 1991, we find that single men earn 1.5 percentage points higher unlevered returns per year on housing relative to single women. The gender gap grows significantly larger after accounting for mortgage borrowing: men earn 7.9 percentage points higher levered returns per year relative to women. Approximately 45% of the gap in housing returns can be explained by gender differences in the location and timing of transactions. The remaining gap arises primarily from gender differences in execution prices: data on repeat sales reveal that women buy the same property for approximately 2% more and sell for 2% less. Women experience worse execution prices because of differences in the choice of initial list price and negotiated discount relative to the list price. Gender differences in upgrade and maintenance rates, and preferences for housing characteristics and listing agents appear to be less important factors. Overall, the gender gap in housing returns is economically large and can explain 30% of the gender gap in wealth accumulation at retirement.

Joining a group diverts regret and responsibility away from the individual
Marwa El Zein & Bahador Bahrami
Proceedings of the Royal Society: Biological Sciences, 11 March 2020


It has recently been proposed that a key motivation for joining groups is the protection from the negative consequences of undesirable outcomes. To test this claim, we investigated how experienced outcomes triggering loss and regret impacted people's tendency to decide alone or join a group, and how decisions differed when voluntarily made alone versus in group. Replicated across two experiments, participants (n = 125 and n = 496) selected whether to play alone or contribute their vote to a group decision. Next, they chose between two lotteries with different probabilities of winning and losing. The higher the negative outcome, the more participants switched from deciding alone to with others. When joining a group to choose the lottery, choices were less driven by outcome and regret anticipation. Moreover, negative outcomes experienced alone, not part of a group vote, led to worse subsequent choices than positive outcomes. These results suggest that the protective shield of the collective reduces the influence of negative emotions that may help individuals re-evaluate past choices.

Predicting variation in endowment effect magnitudes
Christopher Brett Jaeger et al.
Evolution and Human Behavior, forthcoming


Hundreds of studies demonstrate human cognitive biases that are both inconsistent with "rational" decision-making and puzzlingly patterned. One such bias, the "endowment effect" (also known as "reluctance to trade"), occurs when people instantly value an item they have just acquired at a much higher price than the maximum they would have paid to acquire it. This bias impedes a vast range of real-world transactions, making it important to understand. Prior studies have documented items that do or do not generate endowment effects, and have noted that the effects vary in magnitude. But none has predicted any of the substantial between-item variation in those magnitudes across a large and novel set of items. Working from evolutionary theory, we derived six factors that predicted 52% of the between-item variation in magnitudes for a novel set of 24 items. These results deepen understanding of both the causes of and patterns in endowment effects. More broadly, they suggest that many other cognitive biases may be similarly approached, and potentially linked by a common theoretical framework.

Feeling prepared increases confidence in any accessible thoughts affecting evaluation unrelated to the original domain of preparation
Patrick Carroll et al.
Journal of Experimental Social Psychology, forthcoming


The present research shows that preparedness increases reliance on thoughts irrelevant to the domain of preparation. In Study 1, participants wrote positive or negative thoughts about a tuition increase proposal. Next, participants were primed with words related to preparedness or positive control words and reported their evaluations of the initial proposal. Consistent with self-validation theory, results showed that the effect of the direction of thoughts (positive/negative) on attitudes toward tuition was significantly greater when participants were primed with preparedness than control words. A second study replicated and generalized these findings to the domain of social interaction, using a different topic (genetically modified food), and a more natural yet indirect induction of preparedness (expectation to prepare for negative feedback). Study 3 extended these findings by comparing the validating effects of an indirect (expectation) versus a direct (implementation intention) induction of preparedness. Consistent with self-validation theory, moreover, both studies 2 and 3 demonstrated that preparedness and thought confidence mediated the effects of the preparedness manipulations on attitude extremity even though the domain of preparation was unrelated to the domain of evaluation.


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