Probability estimation in poker: A qualified success for unaided judgment

Poker players make strategic decisions on the basis of imperfect information, which are informed by their assessment of the probability they will hold the best set of cards among all players at the conclusion of the hand. Exact mental calculations of this probability are impossible—therefore, players must use judgment to estimate their chances. In three studies, 69 moderately experienced poker players estimated the probability of obtaining the best cards among all players, based on the limited information that is known in the early stages of a hand. Although several of the conditions typically associated with well‐calibrated judgment did not apply, players' judgments were generally accurate. The correlation between judged and true probabilities was r > .8 for over five‐sixths of the participants, and when judgments were averaged across players and within hands this correlation was .96. Players slightly overestimated their chance of obtaining the best cards, mainly where this probability was low to moderate (<.7). Probability estimates were slightly too strongly related to the strength of the two cards that a player holds (known only to themselves), and insufficiently influenced by the number of opponents. Seemingly, players show somewhat insufficient regard for the cards that other players could be holding and the potential for opponents to acquire a strong hand. The results show that even when judgment heuristics are used to good effect in a complex probability estimation task, predictable errors can still be observed at the margins of performance. Copyright © 2009 John Wiley & Sons, Ltd.     

The long and short of it: physical anchoring effects

Attempts to reconstruct the magnitude of recently encountered physical stimuli were influenced by the provision of physical anchors. Whether estimating length, weight, or loudness, those increasing the magnitude of a relatively small (short, light, or quiet) physical anchor produced estimates that were reliably lower than did those decreasing the magnitude of a relatively large (long, heavy, or loud) anchor. Estimates produced without an anchor were also low, suggesting that when people physically adjust upwards from a self‐selected starting point, “no anchor” may, in fact, act as a very low anchor. Physical anchors appear to influence estimates of recently encountered physical stimuli, much as numerical anchors influence estimates of more abstract numerical quantities. Implications for processes underlying anchoring, adjustment, and related tasks are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

Evaluating the effect of delay spacing on delay discounting: carry‐over effects on steepness and the form of the discounting function

Most delay discounting studies use tasks that arrange delay progressions in which the spacing between consecutive delays becomes progressively larger. To date, little research has examined delay discounting using other progressions. The present study assessed whether the form or steepness of discounting varied across different delay progressions. Human participants completed three discounting tasks with delay progressions that varied in the time between consecutive delays: a standard (increasing duration between delays), linear (equal duration between delays), and an inverse progression (decreasing duration between delays). Steepness of discounting was generally reduced, and remained so, following experience with the inverse progression. Effects of the delay progression on the best fitting equation were order‐dependent. Overall the hyperbola model provided better fits, but the exponential model performed better with data from the inverse progression. Regardless, differences in which model fit best were often small. The finding that the best fitting model was dependent, in some cases, on the delay progression suggests that a single quantitative model of discounting may not be applicable to describe discounting across all procedural contexts. Ultimately, changes in steepness of discounting following experience with the inverse progression appeared similar to anchoring effects, whose mechanism will require further study to delineate.     

Motivated to confront: How experiencing anger affects anchoring bias

Prior research has asserted that emotions affect anchoring bias in decision making through the emotion's certainty appraisal or through the emotion's action tendencies, but these prior studies investigate the role of each component—appraisal or action tendency—without accounting for potential effects of the other one. The current research investigates whether anger exerts a significant effect on anchoring bias by activating a desire to confront a potential anchor. Importantly, the studies compare the effect of anger versus disgust, emotions that differ in their action tendency but are similar in their certainty appraisal. In Study 1, participants completed an emotion induction task and then a negotiation task where the first offer from the negotiation partner served as a potential anchor. Anger led to more deviation from the anchor compared with disgust or neutral feelings. Subsequent studies provide evidence that the angry participants are less anchored when the anchor value comes from a more confrontable source (someone else vs. themselves in Study 2 and an out‐group member vs. an in‐group member in Study 3).     

判断与决策中的锚定效应

versky和Kahneman提出锚定与调整启发式以来,锚定效应在不同领域判断与决策研究中得到广泛验证,提出了不同类型的锚定效应、多种研究范式、心理机制的不同理论观点,以及锚定效应作为有关心理现象的内在作用机制。文章阐述了锚定效应的最新研究进展,提出应深化对锚的种类和形态研究,以丰富的技术手段发展锚定效应神经心理机制研究,系统地进行锚定效应影响因素研究,深入探讨锚定现象对人的心理与行为的正负面影响以及锚定效应与其他有关心理现象间的关系     

Confidently Biased: Comparisons with Anchors Bias Estimates and Increase Confidence

Across a wide variety of situations, exposure to anchors has been shown to bias people's estimates. What is not known, however, is whether externally provided anchors influence the confidence that people have in their estimates. Our studies had two goals. First, we tested whether exposure to anchors influenced people's subjective confidence levels (Studies 1 and 2). These studies revealed that people who made estimates after making comparisons with externally provided anchors tended to be more confident in their estimates than people who did not see anchors. The second goal was to test two explanations as to why anchors increase people's confidence. In Study 3, we tested the explanation that anchors increase confidence because participants thought the anchors provided useful information. In Study 4, we tested the explanation that exposure to anchors causes people to consider a narrower range of plausible values as compared to when not exposed to anchors. Support was found only for the explanation that comparisons with anchors increase confidence because people who are exposed to anchors consider a narrower range of plausible values. Taken together, these studies reveal the powerful influence anchors can have—they not only bias estimates, but also increase people's confidence in their biased estimates. Copyright © 2016 John Wiley & Sons, Ltd.     

锚定效应的种类、影响因素及干预措施

锚定效应是指个体在不确定情境下的决策会受到初始无关锚影响致使其随后的数值估计偏向该锚的一种判断偏差现象。不同种类的锚定效应其影响因素和干预措施不同, 如影响传统锚定效应的有锚定信息特征、能力变量、情绪因素及个体差异性等, 基本锚定效应的主要影响因素有知识技能与时间压力, 自发锚定效应则受动机变量、认知因素及内部信念等影响。未来研究可深入挖掘认知加工机制、类比推理过程和开发DDS系统等来帮助减少各种锚定偏差。     

Grounding and anchoring: on the structure of Epstein’s social ontology

Brian Epstein’s The Ant Trap is a praiseworthy addition to literature on social ontology and the philosophy of social sciences. Its central aim is to challenge received views about the social world – views with which social scientists and philosophers have aimed to answer questions about the nature of social science and about those things that social sciences aim to model and explain, like social facts, objects and phenomena. The received views that Epstein critiques deal with these issues in an overly people-centered manner. After all, even though social facts and phenomena clearly involve individual people arranged in certain ways, we must still spell out how people are involved in social facts and phenomena. There are many metaphysical questions about social properties, relations, dependence, constitution, causation, and facts that cannot be answered (for instance) just be looking at individual people alone. In order to answer questions about (e.g.) how one social entity depends for its existence on another, we need different metaphysical tools. Epstein thus holds that social ontological explanations would greatly benefit from making use of the theoretical toolkit that contemporary analytical metaphysics has to offer. He focuses specifically on two metaphysical instruments: grounding and anchoring. This paper examines Epstein’s understanding and use of these tools. I contend that Epstein is exactly right to say that contemporary metaphysics contains many theoretical instruments that can be fruitfully applied to social ontological analyses. However, I am unconvinced that Epstein’s tools achieve what they set out to do. In particular, I will address two issues: (1) How is grounding for Epstein meant to work? (2) Is anchoring distinct from grounding, and a relation that we need in social ontology?