The limits of anchoring

The nature of anchor-biased estimates and its application to the wisdom of crowds

We propose a method to achieve better wisdom of crowds by utilizing anchoring effects. In this method, people are first asked to make a comparative judgment such as "Is the number of new COVID-19 infections one month later more or less than 10 (or 200,000)?" As in this example, two sufficiently different anchors (e.g., "10" or "200,000") are set in the comparative judgment. After this comparative judgment, people are asked to make their own estimates. These estimates are then aggregated. We hypothesized that the aggregated estimates using this method would be more accurate than those without anchor presentation. To examine the effectiveness of the proposed method, we conducted three studies: a computer simulation and two behavioral experiments (numerical estimation of perceptual stimuli and estimation of new COVID-19 infections by physicians). Through computer simulations, we could identify situations in which the proposed method is effective. Although the proposed method is not always effective (e.g., when a group can make fairly accurate estimations), on average, the proposed method is more likely to achieve better wisdom of crowds. In particular, when a group cannot make accurate estimations (i.e., shows biases such as overestimation or underestimation), the proposed method can achieve better wisdom of crowds. The results of the behavioral experiments were consistent with the computer simulation findings. The proposed method achieved better wisdom of crowds. We discuss new insights into anchoring effects and methods for inducing diverse opinions from group members.

Perceptual anchoring effects: Evidence of response bias and a change in estimates sensitivity

INTRODUCTION

People's estimates of perceptual quantities are commonly biased by the contextual presence of other quantities (like numbers). In this study, we address assimilation anchoring effects (approximation of real quantities to contextual quantities) that occur for visually displayed proportions, defining a new methodological setting for the effect.

METHOD

Similar to classic approaches, we asked participants across several trials whether the display contained a feature in a proportion higher or lower than "a randomly selected value" (relative judgments), and then estimated the feature proportions (absolute judgments). Across all trials, we presented seven anchors ranging from .20 to .80, each with a visually displayed representation of the same seven proportions (49 judgments in total). This allowed for a psychophysical approach to individual estimates and signal detection indexes, providing new insights into how the anchoring effect is generated in this setting.

RESULTS

Our findings suggest that anchoring effects occur both as a bias (changes in response criteria) and as a change in the ability to discriminate stimuli (affecting sensitivity indexes). Moreover, anchors modulate the level of stimuli features for which estimates were more uncertain. Finally, our results indicate that anchor effects occur immediately in the first phase of the two-phase paradigm, leading to the availability of values for supporting absolute estimates.

CONCLUSION

By using a psychophysical approach to the anchoring effects, for the first time, we could clarify that this effect is the result of both bias and changes in the ability to discriminate quantity.

Expert assessment of the impact of ship-strikes on cetacean welfare using the Welfare Assessment Tool for Wild Cetaceans

Human activities are increasingly impacting our oceans and the focus tends to be on their environmental impacts, rather than consequences for animal welfare. Global shipping density has quadrupled since 1992. Unsurprisingly, increased levels of vessel collisions with cetaceans have followed this global expansion of shipping. This paper is the first to attempt to consider the severity of ship-strike on individual whale welfare. The methodology of the 'Welfare Assessment Tool for Wild Cetaceans' (WATWC) was used, which is itself based upon the Five Domains model. Expert opinion was sought on six hypothetical but realistic case studies involving humpback whales (Megaptera novaeangliae) struck by ships. Twenty-nine experts in the cetacean and welfare sector took part. They were split into two groups; Group 1 first assessed a case we judged to be the least severe and Group 2 first assessed the most severe. Both groups then additionally assessed the same four further cases. This was to investigate whether the severity of the first case influenced judgements regarding subsequent cases (i.e. expert judgements were relative) or not (i.e. judgements were absolute). No significant difference between the two groups of assessors was found; therefore, the hypothesis of relative scoring was rejected. Experts judged whales may suffer some level (>1) of overall (Domain 5) harm for the rest of their lives following a ship-strike incident. Health, closely followed by Behaviour were found to be the welfare aspects most affected by ship-strikes. Overall, the WATWC shows a robust potential to aid decision-making on wild cetacean welfare.

Anchoring in a Social Context: How the Possibility of Being Misinformed by Others Impacts One's Judgment

Building on research about naïve theories of biases, we propose that people are more likely to engage in critical thinking when assessing others’ reasoning. Hence, anchoring effects should be reduced when anchor values are presented as others’ estimates and people perceive others as less knowledgeable (i.e., more prone to biases) than themselves. Three experiments tested this hypothesis by presenting the same anchors as other participants’ answers or without a specified source. This source manipulation was combined with explicit forewarnings about the anchoring effect, which have been shown to trigger debiasing efforts. In support of our hypothesis, results showed that anchors provided by a social source effectively reduced the anchoring effect and did so in a more reliable way than forewarnings. Furthermore, the response-time analysis in two of the experiments suggests that such attenuation was the result of deliberate adjustment.

Perceptual and Cognitive Judgments Show Both Anchoring and Repulsion

One of the most robust effects in cognitive psychology is anchoring, in which judgments show a bias toward previously viewed values. However, in what is essentially the same task as used in anchoring research, a perceptual illusion demonstrates the opposite effect of repulsion. Here, we united these two literatures, testing in two experiments with adults (total N = 200) whether prior comparative decisions bias cognitive and perceptual judgments in opposing directions or whether anchoring and repulsion are two domain-general biases whose co-occurrence has so far gone undetected. We found that in both perceptual and cognitive tasks, anchoring and repulsion co-occur. Further, the direction of the bias depends on the comparison value: Distant values attract judgments, whereas nearby values repulse judgments. Because none of the leading theories for either effect account for both biases, theoretical integration is needed. As a starting point, we describe one such joint theory based on sampling models of cognition.

Anchors on prices of consumer goods only hold when decisions are hypothetical

We elicit willingness to pay for different types of consumption goods, systematically manipulating irrelevant anchors (high vs. low) and incentives to provide true valuations (hypothetical questions vs. Becker-DeGroot-Marschak mechanism). On top of a strong hypothetical bias, we find that anchors only make a substantial, significant difference in the case of hypothetical data, the first experiments to directly document such an interaction. This finding suggests that hypothetical market research methods may deliver lower quality data. Moreover, it contributes to the discussion examining the mechanism underlying the anchoring effect, suggesting it could partly be caused by insufficient conscious effort to drift away from the anchor.

Noise Increases Anchoring Effects

We introduce a theoretical framework distinguishing between anchoring effects, anchoring bias, and judgmental noise: Anchoring effects require anchoring bias, but noise modulates their size. We tested this framework by manipulating stimulus magnitudes. As magnitudes increase, psychophysical noise due to scalar variability widens the perceived range of plausible values for the stimulus. This increased noise, in turn, increases the influence of anchoring bias on judgments. In 11 preregistered experiments (N = 3,552 adults), anchoring effects increased with stimulus magnitude for point estimates of familiar and novel stimuli (e.g., reservation prices for hotels and donuts, counts in dot arrays). Comparisons of relevant and irrelevant anchors showed that noise itself did not produce anchoring effects. Noise amplified anchoring bias. Our findings identify a stimulus feature predicting the size and replicability of anchoring effects-stimulus magnitude. More broadly, we show how to use psychophysical noise to test relationships between bias and noise in judgment under uncertainty.

Anchoring and Judgment Bias: Disregarding Under Uncertainty

The current investigation examined the nature of the cognitive processes that underlie decision-making behavior. The focus of this project centered on the effects of utilizing heuristics that pertain to the availability of information stored in memory. Anchoring effects demonstrate that people will use any available information sampled from memory as a reference for making judgments of frequency. The specific aim of the experiment was to examine whether people exhibit patterns of behavior consistent with anchoring effects, revealed by corrupted subjective judgments, despite explicit notice of instruction to disregard the experimenter-supplied information (the anchor). Subjects failed to demonstrate an ability to disregard a relatively high anchor even when the instruction to do so was explicit. However, in contrast, subjects demonstrated an ability to disregard a relatively low anchor. More broadly, subjects instructed to disregard demonstrated a reduced effect of anchoring. Implications are considered within the context of the availability heuristic and the directly related effects of anchoring. The results may be interpreted within the framework of a dual-process model, two-system view that distinguishes intuition from reasoning. The present findings fit with well-supported theoretical explanations of anchoring effects, such as selective accessibility and numerical priming.

Behavioral Economics in Information Systems Research: Critical Analysis and Research Strategies

Theories of decision-making have long been important foundations for information systems (IS) research and much of IS is concerned with information processing for decision making. The discipline of behavioral economics (BE) provides the dominant contemporary approach for understanding human decision-making. Therefore, it is logical that IS research that involves decision making should consider BE as foundation or reference theory. Surprisingly, and despite calls for greater use of BE in IS research, it seems that IS has been slow to adopt contemporary BE as reference theory. This paper reports a critical analysis of BE in all fields of IS based on an intensive investigation of quality IS research using bibliometric content analysis. The analysis shows that IS researchers have a general understanding of BE, but their use of the theories has an ad hoc feel where only a narrow range of BE concepts and theories tend to form the foundation of IS research. The factors constraining the adoption of BE theories in IS are discussed and strategies for the use of this influential foundation theory are proposed. Guidance is provided on how BE could be used in various aspects of IS. The paper concludes with the view that BE reference theory has the potential to transform significant areas of IS research.

Decisional carryover effects in interval timing: Evidence of a generalized response bias

Decisional carryover refers to the tendency to report a current stimulus as being similar to a prior stimulus. In this article, we assess decisional carryover in the context of temporal judgments. Participants performed a temporal bisection task wherein a probe between a long and short reference duration (Experiment 1) was presented on every trial. In Experiment 2, every other trial presented a duration the same as the short or long reference duration. In Experiment 3, we concurrently varied both the size and duration of stimuli. Experiment 1 demonstrated the typical decisional carryover effect in which the current response was assimilated towards the prior response. In Experiment 2, this was not the case. Conversely, in Experiment 2, we demonstrated decisional carryover from the prior probe decision to the reference duration trials, a judgment which should have been relatively easy. In Experiment 3, we found carryover in the judgment of both size and duration, and a tendency towards decisional carryover having a larger effect size when participants were making size judgments. Together, our findings indicate that decisional carryover in duration judgments occur given relatively response-certain trials and that this effect appears to be similar in both size and duration judgments. This suggest that decisional carryover is indeed decisional in nature, rather than due to assimilative effects in perception, and that the difficulty of judging the previous test stimuli may play a role in whether assimilation occurs in the following trial when judging duration.

More time, more work: How time limits bias estimates of task scope and project duration

We propose that externally induced time limits on a task overly affect predictions of other people’s completion times for that task, due to an over-generalized association between the time available and inferred task scope. We find higher estimates of the time needed to complete a given task by another person when the time limit is longer. While such predictions could be normative when time limits are informative, the effect persists even when the decision-maker knows that the limit is arbitrary and is unknown to the other person, and therefore, cannot affect behavior. Perception of task scope mediates the relationship between time limits and completion time estimates, and weakening the association between time limits and task scope attenuates the effect. The over-learned cognitive bias persists even among experienced decision-makers making estimates in a familiar setting. Our findings have implications for people who make decisions that use judgments of others’ task completion time as an input.

Variations on anchoring: Sequential anchoring revisited

The anchoring effect, the assimilation of judgment toward a previously considered value, has been shown using various experimental paradigms. We used several variations of the sequential anchoring paradigm, in which a numeric estimate influences a subsequent numeric estimate on the same scale, to investigate how anchoring is influenced by multiple anchors, a comparison question, and by a newly introduced debiasing procedure. We replicated the anchoring effect using the sequential anchoring paradigm and showed that, when two anchors of opposite directions are presented, the second seems to influence a subsequent judgment somewhat more. A comparison of a target with another object before the numerical estimate was not sufficient to elicit anchoring, but it might have increased the sequential anchoring effect. The debiasing procedure, based on providing reference points on the numerical scale, prevented the sequential anchoring effect. The results are in accord with the scale distortion theory of anchoring, but other theories may also account for the observed findings with additional adjustments.

The robustness of anchoring effects on preferential judgments

Anchoring has been shown to influence numeric judgments in various domains, including preferential judgment tasks. Whereas many studies and a recent Many Labs project have shown robust effects in classic anchoring tasks, studies of anchoring effects on preferential judgments have had inconsistent results. In this paper, we investigate the replicability and robustness of anchoring on willingness-to-pay, which is a widely used measure for consumer preference. We employ a combination of approaches, aggregating data from previous studies and also contributing additional replication studies designed to reconcile inconsistent previous results. We examine the effect of differing experimental procedures used in prior studies, and test whether publication bias could contribute to the inconsistent findings. We find that different experimental procedures used in previous studies do not explain the divergent results, and that anchoring effects are generally robust to differences in procedures, participant populations, and experimental settings.

Anchoring and Adjustment in Uncertain Spatial Trajectory Prediction

OBJECTIVE

The aim of this study was to explore the impact of prior information on spatial prediction and understanding of variability.

BACKGROUND

In uncertain spatial prediction tasks, such as hurricane forecasting or planning search-and-rescue operations, decision makers must consider the most likely case and the distribution of possible outcomes. Base performance on these tasks is varied (and in the case of understanding the distribution, often poor). Humans must update mental models and predictions with new information, sometimes under cognitive workload.

METHOD

In a spatial-trajectory prediction task, participants were anchored on accurate or inaccurate information, or not anchored, regarding the future behavior of an object (both average behavior and the variability). Subsequently, they predicted an object's future location and estimated its likelihood at multiple locations. In a second experiment, participants repeated the process under varying levels of external cognitive workload.

RESULTS

Anchoring influenced understanding of most likely predicted location, with fairly rapid adjustment following inaccurate anchors. Increasing workload resulted in decreased overall performance and an impact on the adjustment component of the task. Overconfidence was present in all conditions.

CONCLUSION

Prior information exerted short-term influence on spatial predictions. Cognitive load impaired users' ability to effectively adjust to new information. Accurate graphical anchors did not improve user understanding of variability.

APPLICATION

Prior briefings or forecasts about spatiotemporal trajectories affect decisions even in the face of initial contradictory information. To best support spatial prediction tasks, efforts also need to be made to separate extraneous load-causing tasks from the process of integrating new information. Implications are discussed.

Similarity, multiple estimations, and the anchoring effect

This paper compares the Selective Accessibility and Scale Distortion theories of anchoring as explanations for anchoring tasks involving (1) perceived dissimilarity between comparison and estimation objects and (2) successive estimation tasks. We begin by describing the two theories of anchoring and what each would predict for these conditions. Two studies are presented in which multiple estimates are made following a single comparison task and the effect sizes of these estimates are correlated to operationalizations of similarity. In the first study, the stimuli varied with respect to how well they fit within an existing category reasonably familiar to the participant population: aircraft. In the second study, the stimuli varied with respect to external features that did not define the category: the brand and location of hotels. In both studies, we find that the anchoring effect size has a positive correlation with the semantic similarity between the comparison and estimation objects, a finding consistent with Selective Accessibility.

The anchoring bias reflects rational use of cognitive resources

Cognitive biases, such as the anchoring bias, pose a serious challenge to rational accounts of human cognition. We investigate whether rational theories can meet this challenge by taking into account the mind's bounded cognitive resources. We asked what reasoning under uncertainty would look like if people made rational use of their finite time and limited cognitive resources. To answer this question, we applied a mathematical theory of bounded rationality to the problem of numerical estimation. Our analysis led to a rational process model that can be interpreted in terms of anchoring-and-adjustment. This model provided a unifying explanation for ten anchoring phenomena including the differential effect of accuracy motivation on the bias towards provided versus self-generated anchors. Our results illustrate the potential of resource-rational analysis to provide formal theories that can unify a wide range of empirical results and reconcile the impressive capacities of the human mind with its apparently irrational cognitive biases.

Physician and Nonphysician Estimates of Positive Predictive Value in Diagnostic v. Mass Screening Mammography: An Examination of Bayesian Reasoning

BACKGROUND

The same test with the same result has different positive predictive values (PPVs) for people with different pretest probability of disease. Representative thinking theory suggests people are unlikely to realize this because they ignore or underweight prior beliefs when given new information (e.g., test results) or due to confusing test sensitivity (probability of positive test given disease) with PPV (probability of disease given positive test). This research examines whether physicians and MBAs intuitively know that PPV following positive mammography for an asymptomatic woman is less than PPV for a symptomatic woman and, if so, whether they correctly perceive the difference.

DESIGN

Sixty general practitioners (GPs) and 84 MBA students were given 2 vignettes of women with abnormal (positive) mammography tests: 1 with prior symptoms (diagnostic test), the other an asymptomatic woman participating in mass screening (screening test). Respondents estimated pretest and posttest probabilities. Sensitivity and specificity were neither provided nor elicited.

RESULTS

Eighty-eight percent of GPs and 46% of MBAs considered base rates and estimated PPV in diagnosis greater than PPV in screening. On average, GPs estimated a 27-point difference and MBAs an 18-point difference, compared to actual of 55 or more points. Ten percent of GPs and 46% of MBAs ignored base rates, incorrectly assessing the 2 PPVs as equal.

CONCLUSIONS

Physicians and patients are better at intuitive Bayesian reasoning than is suggested by studies that make test accuracy values readily available to be confused with PPV. However, MBAs and physicians interpret a positive in screening as more similar to a positive in diagnosis than it is, with nearly half of MBAs and some physicians wrongly equating the two. This has implications for overdiagnosis and overtreatment.

The future of waste management in smart and sustainable cities: A review and concept paper

The potential of smart cities in remediating environmental problems in general and waste management, in particular, is an important question that needs to be investigated in academic research. Built on an integrative review of the literature, this study offers insights into the potential of smart cities and connected communities in facilitating waste management efforts. Shortcomings of existing waste management practices are highlighted and a conceptual framework for a centralized waste management system is proposed, where three interconnected elements are discussed: (1) an infrastructure for proper collection of product lifecycle data to facilitate full visibility throughout the entire lifespan of a product, (2) a set of new business models relied on product lifecycle data to prevent waste generation, and (3) an intelligent sensor-based infrastructure for proper upstream waste separation and on-time collection. The proposed framework highlights the value of product lifecycle data in reducing waste and enhancing waste recovery and the need for connecting waste management practices to the whole product life-cycle. An example of the use of tracking and data sharing technologies for investigating the waste management issues has been discussed. Finally, the success factors for implementing the proposed framework and some thoughts on future research directions have been discussed.

Not all Anchors Weigh Equally

The anchoring bias is a reliable effect wherein a person's judgments are affected by initially presented information, but it is unknown specifically why this effect occurs. Research examining this bias suggests that elements of both numeric and semantic priming may be involved. To examine this, the present research used a phenomenon wherein people treat numeric information presented differently in Arabic numeral or verbal formats. We presented participants with one of many forms of an anchor that represented the same value (e.g., twelve hundred or 1,200). Thus, we could examine how a concept's meaning and its absolute numeric value affect anchoring. Experiments 1 and 2 showed that people respond to Arabic and verbal anchors differently. Experiment 3 showed that these differences occurred largely because people tend to think of numbers in digit format. This suggests that one's conceptual understanding of the anchored information matters more than its strict numeric value.

Small Cues Change Savings Choices

We present evidence from randomized field experiments that 401(k) savings choices are significantly affected by one- to two-sentence anchoring, goal-setting, or savings threshold cues embedded in emails sent to employees about their 401(k) plan. Even though these cues contain little to no marginal information, cues that make high savings rates salient increased 401(k) contribution rates by up to 2.9% of income in a pay period, and cues that make low savings rates salient decreased 401(k) contribution rates by up to 1.4% of income in a pay period. Cue effects persist between two months and a year after the email.

When your anchor sinks your boat: Information asymmetry in distributive negotiations and the disadvantage of making the first offer

The literature on behavioral decision-making and negotiations to date usually advocates first-mover advantage in distributive negotiations, and bases this preference on the anchoring heuristic. In the following paper, we suggest that the preference for moving first vs. moving second in negotiations may not be as clear-cut as presumed, especially in situations characterized by information asymmetry between negotiating counterparts. In Study 1, we examined people’s initiation preferences and found that unless taught otherwise, people intuitively often prefer to move second. In Studies 2–4, we experimentally tested the suggested advantage of moving second, and demonstrated that in information-asymmetry scenarios – when one party has perfect background information and the other has none — it is actually preferable for both counterparts not to give the first offer while negotiating. We discuss the implications of our findings on the field of negotiation and decision-making, and lay the groundwork for future studies examining this issue.

Attention and attribute overlap in preferential choice

Attributes that are common, or overlapping, across alternatives in two-alternative forced preferential choice tasks are often non-diagnostic. In many settings, attending to and evaluating these attributes does not help the decision maker determine which of the available alternatives is the most desirable. For this reason, many existing behavioural theories propose that decision makers ignore common attributes while deliberating. Across six experiments, we find that decision makers do direct their attention selectively and ignore attributes that are not present in or associated with either of the available alternatives. However, they are as likely to attend to common attributes as they are to attend to attributes that are unique to a single alternative. These results suggest the need for novel theories of attention in preferential choice.

Academic judgments under uncertainty: A study of collective anchoring effects in Swedish Research Council panel groups

This article focuses on anchoring effects in the process of peer reviewing research proposals. Anchoring effects are commonly seen as the result of flaws in human judgment, as cognitive biases that stem from specific heuristics that guide people when they involve their intuition in solving a problem. Here, the cognitive biases will be analyzed from a sociological point of view, as interactional and aggregated phenomena. The article is based on direct observations of ten panel groups evaluating research proposals in the natural and engineering sciences for the Swedish Research Council. The analysis suggests that collective anchoring effects emerge as a result of the combination of the evaluation techniques that are being used (grading scales and average ranking) and the efforts of the evaluators to reach consensus in the face of disagreements and uncertainty in the group. What many commentators and evaluators have interpreted as an element of chance in the peer review process may also be understood as partly a result of the dynamic aspects of collective anchoring effects.

Semantic cross-scale numerical anchoring

Anchoring effects are robust, varied and can be consequential. Researchers have provided a variety of alternative explanations for these effects. More recently, it has become apparent that anchoring effects might be produced by a variety of different processes, either acting simultaneously, or else individually in distinct situations. An unresolved issue is whether anchoring, aside from simple numeric priming, can transcend scales. That is, is it necessary that the anchor value and the target judgment are expressed in the same units? Despite some theoretical predictions to the contrary, this paper demonstrates semantic cross-scale anchoring in four experiments. Such effects are important for the direction of future theorising on the causes of anchoring effects and understanding the scope of their consequences in applied domains.

Anchoring and Adjustment With Spatial Uncertainty in Trajectory Prediction

Anchoring and adjustment is a prevalent heuristic, common in a range of settings and decisions. While it is well studied using values, there has been limited research on its function in visual-spatial domains. The present study explored the role of anchoring and adjustment with visual displays containing uncertainty information related to spatial prediction. Participants were given a graphical briefing to anchor them on accurate, inaccurate, or no information regarding the future behavior of an object (both its average behavior and the variance in behavior). They then made predictions of future object location and estimated its likelihood at multiple locations. Overall individuals utilized the anchoring information and were able to adjust to incorrect anchors. However, individuals vastly overestimated the likelihood the object would be at any given location, suggesting that they were not anchored on the variance.

The anchor integration model: A descriptive model of anchoring effects

Few experimental effects in the psychology of judgment and decision making have been studied as meticulously as the anchoring effect. Although the existing literature provides considerable insight into the psychological processes underlying anchoring effects, extant theories up to this point have only generated qualitative predictions. While these theories have been productive in advancing our understanding of the underlying anchoring process, they leave much to be desired in the interpretation of specific anchoring effects. In this article, we introduce the Anchor Integration Model (AIM) as a descriptive tool for the measurement and quantification of anchoring effects. We develop two versions the model: one suitable for assessing between-participant anchoring effects, and another for assessing individual differences in anchoring effects. We then fit each model to data from two experiments, and demonstrate the model's utility in describing anchoring effects.

Egoism Bias in Social Dilemmas with Resource Uncertainty

In Experiment 1 we investigated size estimates and requests from an uncertain resource in a common-pool resource dilemma. In Experiment 2, we examined contributions in a public-good dilemma with an uncertain provision threshold when participants were informed about others’ pessimistically biased estimates of the resource size or provision threshold. Supporting an individual outcome-desirability bias, but refuting a perceptual bias and an egoism bias, participants in Experiment 1 did not estimate size differently, and they cooperated more, rather than less, when they were informed about others’ estimates. Likewise, participants contributed more in Experiment 2 when they were informed about others’ estimates. These results were replicated in Experiment 3, where the outcome did not depend on others’ requests or contributions.

Are Adjustments Insufficient?

Many judgmental biases are thought to be the product of insufficient adjustment from an initial anchor value. Nearly all existing evidence of insufficient adjustment, however, comes from an experimental paradigm that evidence indicates does not involve adjustment at all. In this article, the authors first provide further evidence that some kinds of anchors (those that are self-generated and known to be incorrect but close to the correct answer) activate processes of adjustment, whereas others (uncertain anchors provided by an external source) do not. It is then shown that adjustment from self-generated anchors does indeed tend to be insufficient, both by comparing the estimates of participants starting from different anchor values and by comparing estimates with actual answers. Thus, evidence is provided of adjustment-based anchoring effects similar to the accessibility-based anchoring effects observed in the traditional anchoring paradigm, supporting theories of social judgment that rely on mechanisms of insufficient adjustment.

Next to a Star: Paling, Shining, or Both? Turning Interexemplar Contrast into Interexemplar Assimilation

Four studies, set in the political and marketing domain, investigated how an extreme exemplar influences the evaluation of more moderate exemplars. In Studies 1 to 3, an extremely positive exemplar (star) elicited contrast in the evaluation of more moderate exemplars. However, the contrast effect was eliminated when the shared category membership of the star and the respective exemplar was made salient. Rather than relying on categorization, Study 4 manipulated interexemplar assimilation by using comparison processes to draw attention to the features shared with an extreme exemplar. Whether the extreme exemplar caused contrast or assimilation depended on the direction of comparison with which target and context stimulus were compared. All studies, in particular Studies 3 and 4, suggest that interexemplar contrast and interexemplar assimilation work in parallel rather than alternatively.

Anchoring in Destination-Therapy Left Ventricular Assist Device Decision Making: A Mechanical Turk Survey

BACKGROUND

People with end-stage heart failure may have to decide about destination-therapy left ventricular assist device (DT-LVAD). Individuals facing difficult decisions often rely on heuristics, such as anchoring, which predictably bias decision outcomes. We aimed to investigate whether showing a larger historical Heartmate XVE creates an anchoring effect, making the smaller Heartmate II (HMII) appear more favorable.

METHODS

With the use of Amazon Mechanical Turk, participants watched videos asking them to imagine themselves dying of end-stage heart failure, then were presented the option of LVAD as potentially life-prolonging therapy. Participants were randomized to a control group who were only shown the HMII device, and the intervention group who saw the XVE device before the HMII. Participants then completed surveys.

RESULTS

A total of 487 participants completed the survey (control = 252; intervention = 235); 79% were <40 years of age, 84% were white, and 55% were male. The intervention group was not more likely to accept the LVAD therapy (68% vs 61%; P = .37). However, participants in the intervention group were more likely (51% vs 17%; P < .01) to agree or strongly agree with the statement that the HMII was "smaller than expected." Participants in the intervention group were also more likely to rate the size of the device as "important" or "very important" in their decision (61% vs 46%; P < .01).

CONCLUSIONS

Although the XVE anchor did not affect likelihood of accepting the LVAD, it did affect device perception. This article highlights an important point with clinical implications: factors such as anchoring have the potential to inappropriately influence perceptions and decisions and should be carefully considered in research and practice.

Anchoring in Numeric Judgments of Visual Stimuli

This article investigates effects of anchoring in age estimation and estimation of quantities, two tasks which to different extents are based on visual stimuli. The results are compared to anchoring in answers to classic general knowledge questions that rely on semantic knowledge. Cognitive load was manipulated to explore possible differences between domains. Effects of source credibility, manipulated by differing instructions regarding the selection of anchor values (no information regarding anchor selection, information that the anchors are randomly generated or information that the anchors are answers from an expert) on anchoring were also investigated. Effects of anchoring were large for all types of judgments but were not affected by cognitive load or by source credibility in either one of the researched domains. A main effect of cognitive load on quantity estimations and main effects of source credibility in the two visually based domains indicate that the manipulations were efficient. Implications for theoretical explanations of anchoring are discussed. In particular, because anchoring did not interact with cognitive load, the results imply that the process behind anchoring in visual tasks is predominantly automatic and unconscious.

Common sense and sociological explanations

Sociologists have long advocated a sociological approach to explanation by contrasting it with common sense. The argument of this article, however, is that sociologists rely on common sense more than they realize. Moreover, this unacknowledged reliance causes serious problems for their explanations of social action, that is, for why people do what they do. Many such explanations, it is argued, conflate understandability with causality in ways that are not valid by the standards of scientific explanation. It follows that if sociologists want their explanations to be scientifically valid, they must evaluate them specifically on those grounds--in particular, by forcing them to make predictions. In becoming more scientific, however, it is predicted that sociologists' explanations will also become less satisfying from an intuitive, sense-making perspective. Even as novel sources of data and improved methods open exciting new directions for sociological research, therefore, sociologists will increasingly have to choose between unsatisfying scientific explanations and satisfying but unscientific stories.

The Tendency to Fall for Distracting Information While Making Judgments

Despite much research on thinking biases such as the representativeness, availability, and anchoring heuristics, a psychometrically sound measurement instrument for assessing the degree of heuristic thinking is still missing. Therefore, it was the goal of this study to develop and validate a new test to assess the degree of heuristic thinking associated with three particular thinking heuristics (i.e., the representativeness, availability, and anchoring heuristics). The resulting Objective Heuristic Thinking Test (OHTT) was evaluated with regard to its internal consistency, factor structure, construct validity, and stability in an internet sample (N = 300) and an independent laboratory sample (N = 55). Exploratory factor analyses resulted in three latent factors that represented the three OHTT subscales (i.e., representativeness, availability, and anchoring factors). Results revealed a low to sufficient internal consistency for each of the three scales. Further analyses indicated convergent correlations of the OHTT scales with related constructs such as field-independency. Furthermore, good stability of the test scores was shown. Conclusions are drawn regarding possible future applications of the OHTT as a promising tool for studying the origins of heuristic thinking processes.