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Sunday, November 4, 2012

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Sources of Bias in Retrospective Decision Making: Experimental Evidence on Voters' Limitations in Controlling Incumbents

Gregory Huber, Seth Hill & Gabriel Lenz
American Political Science Review, forthcoming

Abstract:
Are citizens competent to assess the performance of incumbent politicians? Observational studies cast doubt on voter competence by documenting several biases in retrospective assessments of performance. However, these studies are open to alternative interpretations because of the complexity of the real world. In this article, we show that these biases in retrospective evaluations occur even in the simplified setting of experimental games. In three experiments, our participants (1) overweighted recent relative to overall incumbent performance when made aware of an election closer rather than more distant from that event, (2) allowed an unrelated lottery that affected their welfare to influence their choices, and (3) were influenced by rhetoric to give more weight to recent rather than overall incumbent performance. These biases were apparent even though we informed and incentivized respondents to weight all performance equally. Our findings point to key limitations in voters' ability to use a retrospective decision rule.

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A Dose of Ruthlessness: Interpersonal Moral Judgment Is Hardened by the Anti-Anxiety Drug Lorazepam

Adam Perkins et al.
Journal of Experimental Psychology: General, forthcoming

Abstract:
Neuroimaging data suggest that emotional brain systems are more strongly engaged by moral dilemmas in which innocent people are directly harmed than by dilemmas in which harm is remotely inflicted. In order to test the possibility that this emotional engagement involves anxiety, we investigated the effects of 1 mg and 2 mg of the anti-anxiety drug lorazepam on the response choices of 40 healthy volunteers (20 male) in moral-personal, moral-impersonal, and nonmoral dilemmas. We found that lorazepam caused a dose-dependent increase in participants' willingness to endorse responses that directly harm other humans in moral-personal dilemmas but did not significantly affect response choices in moral-impersonal dilemmas or nonmoral dilemmas. Within the set of moral-personal dilemmas that we administered, lorazepam increased the willingness to harm others in dilemmas where harm was inflicted for selfish reasons (dubbed low-conflict dilemmas) as well as responses to dilemmas where others were harmed for utilitarian reasons (i.e., for the greater good, dubbed high-conflict dilemmas). This suggests that anxiety exerts a general inhibitory effect on harmful acts toward other humans regardless of whether the motivation for those harmful acts is selfish or utilitarian. Lorazepam is also a sedative drug, but we found that lorazepam slowed decision times equally in all 3 dilemma types. This finding implies that its specific capacity to increase ruthlessness in moral-personal dilemmas was not a confound caused by sedation.

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The Herding Hormone: Oxytocin Stimulates In-Group Conformity

Mirre Stallen et al.
Psychological Science, forthcoming

Abstract:
People often conform to others with whom they associate. Surprisingly, however, little is known about the possible hormonal mechanisms that may underlie in-group conformity. Here, we examined whether conformity toward one's in-group is altered by oxytocin, a neuropeptide often implicated in social behavior. After administration of either oxytocin or a placebo, participants were asked to provide attractiveness ratings of unfamiliar visual stimuli. While viewing each stimulus, participants were shown ratings of that stimulus provided by both in-group and out-group members. Results demonstrated that on trials in which the ratings of the in-group and out-group were incongruent, the ratings of participants given oxytocin conformed to the ratings of their in-group but not of their out-group. Participants given a placebo did not show this in-group bias. These findings indicate that administration of oxytocin can influence subjective preferences, and they support the view that oxytocin's effects on social behavior are context dependent.

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Revisiting the agentic shift: Weakening personal control increases susceptibility to social influence

Bob Fennis & Henk Aarts
European Journal of Social Psychology, forthcoming

Abstract:
What happens when people experience a reduced sense of personal control? Among the various strategies to defend against a perception of randomness, people may show an increased acceptance of external sources of control. Indeed, in one of the most classic studies in social psychology, Stanley Milgram referred to an "agentic shift" - the tendency to relinquish personal control to an external agent - to explain his dramatic obedience effects. We propose that his account is a specific manifestation of a more general phenomenon: the tendency for increased susceptibility to various forms of external social influence when perceived personal control is reduced. In a series of (lab and field) studies using a variety of perceived control manipulations, we demonstrate that a reduction in the sense of personal control increases people's vulnerability to the bystander effect, promotes obedience to authority and fosters compliance with behavioral requests.

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Morality and conformity: The Asch paradigm applied to moral decisions

Payel Kundu & Denise Dellarosa Cummins
Social Influence, forthcoming

Abstract:
Morality has long been considered an inherent quality, an internal moral compass that is unswayed by the actions of those around us. The Solomon Asch paradigm was employed to gauge whether moral decision making is subject to conformity under social pressure as other types of decision making have been shown to be. Participants made decisions about moral dilemmas either alone or in a group of confederates posing as peers. On a majority of trials confederates rendered decisions that were contrary to judgments typically elicited by the dilemmas. The results showed a pronounced effect of conformity: Compared to the control condition, permissible actions were deemed less permissible when confederates found them objectionable, and impermissible actions were judged more permissible if confederates judged them so.

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The Burden of Disclosure: Increased Compliance With Distrusted Advice

Sunita Sah, George Loewenstein & Daylian Cain
Journal of Personality and Social Psychology, forthcoming

Abstract:
Professionals often face conflicts of interest that give them an incentive to provide biased advice, and disclosure (informing advisees about the conflict) is frequently proposed as a solution to the problem. We present 6 experiments that reveal a previously unrecognized perverse effect of disclosure: Although disclosure can decrease advisees' trust in the advice, it can also increase pressure to comply with that advice if advisees feel obliged to satisfy their advisors' personal interests. Hence, disclosure can burden those it is ostensibly intended to protect. Beyond demonstrating the effect, we show that this increased pressure to comply with advice is reduced if (a) the disclosure is provided by an external source rather than from the advisor, (b) the disclosure is not common knowledge between the advisor and advisee, (c) the advisee has an opportunity to change his/her mind later, or (d) the advisee is able to make the decision in private.

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Consequences are far away: Psychological distance affects modes of moral decision making

Han Gong, Rumen Iliev & Sonya Sachdeva
Cognition, forthcoming

Abstract:
Much of the work on deontological and consequentialist moral choices assumes that these modes of decision making are rooted in individual differences or cognitive capacities. We examine the idea that whether a person focuses on actions or outcomes while making moral choices depends on the psychological distance from the moral situation. When the situation is perceived as far off, whether in time or space, consequentialist considerations loom larger. In the first four studies in this paper, we establish that psychological distance from an event decreases deontological judgments and increases consequentialist choices. This effect holds across two distinct paradigms. Finally, in Experiment 5 we use Construal Level Theory to suggest that deontology and consequentialist reasoning may be linked to how information is represented at near and far distances. This work implies that decision makers have several distinct strategies when making moral choices but the selection of those strategies is far from fixed, and may depend on factors such as psychological distance.

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The Human Factor: Behavioral and Neural Correlates of Humanized Perception in Moral Decision Making

Jasminka Majdandžić et al.
PLoS ONE, October 2012

Abstract:
The extent to which people regard others as full-blown individuals with mental states ("humanization") seems crucial for their prosocial motivation towards them. Previous research has shown that decisions about moral dilemmas in which one person can be sacrificed to save multiple others do not consistently follow utilitarian principles. We hypothesized that this behavior can be explained by the potential victim's perceived humanness and an ensuing increase in vicarious emotions and emotional conflict during decision making. Using fMRI, we assessed neural activity underlying moral decisions that affected fictitious persons that had or had not been experimentally humanized. In implicit priming trials, participants either engaged in mentalizing about these persons (HUMANIZED condition) or not (NEUTRAL condition). In subsequent moral dilemmas, participants had to decide about sacrificing these persons' lives in order to save the lives of numerous others. Humanized persons were sacrificed less often, and the activation pattern during decisions about them indicated increased negative affect, emotional conflict, vicarious emotions, and behavioral control (pgACC/mOFC, anterior insula/IFG, aMCC and precuneus/PCC). Besides, we found enhanced effective connectivity between aMCC and anterior insula, which suggests increased emotion regulation during decisions affecting humanized victims. These findings highlight the importance of others' perceived humanness for prosocial behavior - with aversive affect and other-related concern when imagining harming more "human-like" persons acting against purely utilitarian decisions.

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Psychological Distance Can Improve Decision Making Under Information Overload Via Gist Memory

Jun Fukukura, Melissa Ferguson & Kentaro Fujita
Journal of Experimental Psychology: General, forthcoming

Abstract:
Making a decision can be especially difficult when it is based upon a large amount of information. A number of demonstrations in the literature suggest that decision making under information overload leads to suboptimal outcomes. In this article, we draw on construal level theory (Trope & Liberman, 2003) and fuzzy-trace theory (Brainerd & Reyna, 1993) to suggest that psychologically distancing oneself from the information can be beneficial to decision making under information overload. Specifically, we propose that distancing prompts organization of information in terms of its gist. Across 4 studies, we demonstrated that increasing spatial distance, temporal distance, and abstraction lead to better decision outcomes when decision makers were overloaded with many pieces of information per decision. Furthermore, we showed that the relationship between psychological distance and decision outcome is mediated by gist memory.

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Shopping for a home vs. a loan: The role of cognitive resource depletion

Vanessa Gail Perry & Joonwhan David Lee
International Journal of Consumer Studies, September 2012, Pages 580-587

Abstract:
The authors suggest that the process of shopping for a home and choosing between alternative property features depletes individuals' cognitive resources, which in turn results in sub-optimal home financing decisions. Thus, in the span of time that follows the shopping experience, consumers will devote less attention to choosing a mortgage, resulting in a higher propensity to select higher-risk, adjustable-rate mortgage products. The results of two controlled experiments demonstrate that participants in an online house shopping simulation were more likely to select one of the high-risk mortgage offers, and spent less time selecting a mortgage than participants in the control condition. In addition, contrary to expectations, warning participants about cognitive resource depletion exacerbated these effects. These findings imply that consumer decisions could be improved by imposing a temporal separation between shopping for a home and shopping for financing.

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Evidence for the influence of the mere-exposure effect on voting in the Eurovision Song Contest

Diarmuid Verrier
Judgment and Decision Making, September 2012, Pages 639-643

Abstract:
The mere exposure, or familiarity, effect is the tendency for people to feel more positive about stimuli to which they have previously been exposed. The Eurovision Song Contest is a two-stage event, in which some contestants in the final will be more familiar to viewers than others. Thus, viewers' voting is likely to be influenced by this effect. Previous work attempting to demonstrate this effect in this context has been unable to control for contestant quality. The current study, which used a novel procedure to analyse the way in which contestant countries distributed their points (a function of how viewers voted in those countries) between 2008 and 2011, showed that contestants did better if they previously appeared in a semifinal that was seen by voters. This is evidence that the mere exposure effect, alongside previously studied factors such as cultural and geographical closeness, influences the way viewers vote in the Eurovision.

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When should I trust my gut? Linking domain expertise to intuitive decision-making effectiveness

Erik Dane, Kevin Rockmann & Michael Pratt
Organizational Behavior and Human Decision Processes, November 2012, Pages 187-194

Abstract:
Despite a growing body of scholarship on the concept of intuition, there is a scarcity of empirical research spotlighting the circumstances in which intuitive decision making is effective relative to analytical decision making. Seeking to address this deficiency, we conducted two laboratory studies assessing the link between domain expertise (low versus high) and intuitive decision-making effectiveness. These studies involved non-decomposable tasks across divergent expertise domains: basketball in Study 1 and designer handbag authentication in Study 2. Across both studies, and consistent with our overarching hypothesis, we found that the effectiveness of intuition relative to analysis is amplified at a high level of domain expertise. Taken together, our results demonstrate the importance of domain expertise in intuitive decision making and carry a number of theoretical and practical implications.

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When Less Is More: Evolutionary Origins of the Affect Heuristic

Jerald Kralik et al.
PLoS ONE, October 2012

Abstract:
The human mind is built for approximations. When considering the value of a large aggregate of different items, for example, we typically do not summate the many individual values. Instead, we appear to form an immediate impression of the likeability of the option based on the average quality of the full collection, which is easier to evaluate and remember. While useful in many situations, this affect heuristic can lead to apparently irrational decision-making. For example, studies have shown that people are willing to pay more for a small set of high-quality goods than for the same set of high-quality goods with lower-quality items added [e.g. 1]. We explored whether this kind of choice behavior could be seen in other primates. In two experiments, one in the laboratory and one in the field, using two different sets of food items, we found that rhesus monkeys preferred a highly-valued food item alone to the identical item paired with a food of positive but lower value. This finding provides experimental evidence that, under certain conditions, macaque monkeys follow an affect heuristic that can cause them to prefer less food. Conservation of this affect heuristic could account for similar ‘irrational' biases in humans, and may reflect a more general complexity reduction strategy in which averages, prototypes, or stereotypes represent a set or group.

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Choice Behavior of Pigeons (Columba livia), College Students, and Preschool Children (Homo sapiens) in the Monty Hall Dilemma

James Mazur & Patricia Kahlbaugh
Journal of Comparative Psychology, forthcoming

Abstract:
In the Monty Hall dilemma, an individual chooses between three options, only one of which will deliver a prize. After the initial choice, one of the nonchosen options is revealed as a losing option, and the individual can choose to stay with the original choice or switch to the other remaining option. Previous studies have found that most adults stay with their initial choice, although the chances of winning are 2/3 for switching and 1/3 for staying. Pigeons, college students, and preschool children were given many trials on this task to examine how their choices might change with experience. The college students began to switch on a majority of trials much sooner than the pigeons, contrary to the findings by Herbranson and Schroeder (2010) that pigeons perform better than people on this task. In all three groups, some individuals approximated the optimal strategy of switching on every trial, but most did not. Many of the preschoolers immediately showed a pattern of always switching or always staying and continued this pattern throughout the experiment. In a condition where the probability of winning was 90% after a switch, all college students and all but one pigeon learned to switch on nearly every trial. The results suggest that one main impediment to learning the optimal strategy in the Monty Hall task, even after repeated trials, is the difficulty in discriminating the different reinforcement probabilities for switching versus staying.

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Effects of perspective and belief on analytic reasoning in a scientific reasoning task

Erin Beatty & Valerie Thompson
Thinking & Reasoning, Fall 2012, Pages 441-460

Abstract:
The purpose of these studies was to test the hypothesis that changing perspectives from one's own to another's promotes the engagement of analytic processing and, in turn, reduces the impact of beliefs. In two experiments participants evaluated research vignettes containing belief-consistent and belief-inconsistent conclusions, and indicated whether the data supported a correlation between two variables. Consistent with our hypothesis, the tendency to endorse correlations consistent with prior belief was reduced when participants evaluated the data from the researcher's perspective relative to their own. We also administered the Actively Open Minded Thinking (AOT) scale (Stanovich & West, 2007, 2008), which did not predict belief effects on our task. We did however observe that the AOT was reliably associated with different response strategies: high AOT scorers were more inclined to choose ambiguous response options, such as "no conclusion is warranted", whereas low scorers evinced a preference for more determinate options (e.g., there is no relationship between the two variables). We interpret our findings in the context of dual process theories of reasoning and from a Bayesian perspective.

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On Avoiding Framing Effects in Experienced Decision Makers

Rocio Garcia-Retamero & Mandeep Dhami
Quarterly Journal of Experimental Psychology, forthcoming

Abstract:
The present study aimed to (1) demonstrate the effect of positive-negative framing on experienced criminal justice decision makers, (2) examine the debiasing effect of visually structured risk messages, and (3) investigate whether risk perceptions mediate the debiasing effect of visual aids on decision making. In two phases, 60 senior police officers estimated the accuracy of a counter-terrorism technique in identifying whether a known terror suspect poses an imminent danger, and decided whether they would recommend the technique to policy makers. Officers also rated their confidence in this recommendation. When information about the effectiveness of the counter-terrorism technique was presented in a numerical format, officers' perceptions of accuracy and recommendation decisions were susceptible to the framing effect: The technique was perceived to be more accurate and was more likely to be recommended when its effectiveness was presented in a positive than negative frame. However, when the information was represented visually using icon arrays, there were no such framing effects. Finally, perceptions of accuracy mediated the debiasing effect of visual aids on recommendation decisions. We offer potential explanations for the debiasing effect of visual aids, and implications for communicating risk to experienced, professional decision makers.

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Normative arguments from experts and peers reduce delay discounting

Nicole Senecal et al.
Judgment and Decision Making, September 2012, Pages 566-589

Abstract:
When making decisions that involve tradeoffs between the quality and timing of desirable outcomes, people consistently discount the value of future outcomes. A puzzling finding regarding such decisions is the extremely high rate at which people discount future monetary outcomes. Most economists would argue that decision-makers should turn down only rates of return that are lower than those available to them elsewhere. Yet the vast majority of studies find discount rates that are significantly higher than market interest rates (Frederick et al., 2002). Here we ask whether a lack of knowledge about the normative strategy can explain high discount rates. In an initial experiment, nearly half of subjects did not spontaneously cite elements of the normative strategy when asked how people should make intertemporal monetary decisions. In two follow-up experiments, after subjects read a "financial guide" detailing the normative strategy, discount rates declined by up to 85%, but were still higher than market interest rates. This decline persisted, though attenuated, for at least one month. In a final experiment, peer-generated advice influenced discount rates in a similar manner to "expert" advice, and arguments focusing on normative considerations were at least as effective as others. These studies show that part of the explanation for high discount rates is a lack of knowledge regarding the normative strategy, and they quantify how much discount rates are reduced in response to normative arguments. Given the high level of discounting that remains, however, there are other contributing factors to high discount rates that remain to be quantified.

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Professional Physical Scientists Display Tenacious Teleological Tendencies: Purpose-Based Reasoning as a Cognitive Default

Deborah Kelemen, Joshua Rottman & Rebecca Seston
Journal of Experimental Psychology: General, forthcoming

Abstract:
Teleological explanations account for objects and events by reference to a functional consequence or purpose. Although they are popular in religion, they are unpopular in science: Physical scientists in particular explicitly reject them when explaining natural phenomena. However, prior research provides reasons to suspect that this explanatory form may represent a default explanatory preference. As a strong test of this hypothesis, we explored whether physical scientists endorse teleological explanations of natural phenomena when their information-processing resources are limited. In Study 1, physical scientists from top-ranked American universities judged explanations as true or false, either at speed or without time restriction. Like undergraduates and age-matched community participants, scientists demonstrated increased acceptance of unwarranted teleological explanations under speed despite maintaining high accuracy on control items. Scientists' overall endorsement of inaccurate teleological explanation was lower than comparison groups, however. In Study 2, we explored this further and found that the teleological tendencies of professional scientists did not differ from those of humanities scholars. Thus, although extended education appears to produce an overall reduction in inaccurate teleological explanation, specialization as a scientist does not, in itself, additionally ameliorate scientifically inaccurate purpose-based theories about the natural world. A religion-consistent default cognitive bias toward teleological explanation tenaciously persists and may have subtle but profound consequences for scientific progress.

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Thinking like a scientist: Innateness as a case study

Joshua Knobe & Richard Samuels
Cognition, January 2013, Pages 72-86

Abstract:
The concept of innateness appears in systematic research within cognitive science, but it also appears in less systematic modes of thought that long predate the scientific study of the mind. The present studies therefore explore the relationship between the properly scientific uses of this concept and its role in ordinary folk understanding. Studies 1-4 examined the judgments of people with no specific training in cognitive science. Results showed (a) that judgments about whether a trait was innate were not affected by whether or not the trait was learned, but (b) such judgments were impacted by moral considerations. Study 5 looked at the judgments of both non-scientists and scientists, in conditions that encouraged either thinking about individual cases or thinking about certain general principles. In the case-based condition, both non-scientists and scientists showed an impact of moral considerations but little impact of learning. In the principled condition, both non-scientists and scientists showed an impact of learning but little impact of moral considerations. These results suggest that both non-scientists and scientists are drawn to a conception of innateness that differs from the one at work in contemporary scientific research but that they are also both capable of ‘filtering out' their initial intuitions and using a more scientific approach.

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Exploiting the Wisdom of Others to Make Better Decisions: Suspending Judgment Reduces Egocentrism and Increases Accuracy

Ilan Yaniv & Shoham Choshen-Hillel
Journal of Behavioral Decision Making, December 2012, Pages 427-434

Abstract:
Although decision makers often consult other people's opinions to improve their decisions, they fail to do so optimally. One main obstacle to incorporating others' opinions efficiently is one's own opinion. We theorize that decision makers could improve their performance by suspending their own judgment. In three studies, participants used others' opinions to estimate uncertain quantities (the caloric value of foods). In the full-view condition, participants could form independent estimates prior to receiving others' opinions, whereas participants in the blindfold condition could not form prior opinions. We obtained an intriguing blindfold effect. In all studies, the blindfolded participants provided more accurate estimates than did the full-view participants. Several policy-capturing measures indicated that the advantage of the blindfolded participants was due to their unbiased weighting of others' opinions. The full-view participants, in contrast, adhered to their prior opinion and thus failed to exploit the information contained in others' opinions. Moreover, in all three studies, the blindfolded participants were not cognizant of their advantage and expressed less confidence in their estimates than did the full-view participants. The results are discussed in relation to theories of opinion revision and group decision making.

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Gamblers can discriminate ‘tight' from ‘loose' electronic gambling machines

Mike Dixon et al.
International Gambling Studies, forthcoming

Abstract:
All slot machines make money over time, but the payouts to the players can differ. ‘Loose' machines pay out more than ‘tight' machines. Gamblers (n = 1402) at Ontario slots venues were assessed using the Problem Gambling Severity Index. Their beliefs about slots were polled using the Informational Biases Scale. Problem gamblers were more likely than non-problem and at-risk gamblers to endorse the belief that ‘some slot machines keep me from winning because they are programmed to produce fewer wins than normal'. We then showed that after extensive play (60 hours), 9 out of 10 gamblers were able to correctly discriminate a ‘loose' machine (98% payback) from a ‘tight' machine (85% payback). Problem gamblers' assertions that there are ‘loose' and ‘tight' machines demonstrate a belief rooted in reality. The ability to distinguish ‘loose' from ‘tight' machines may be interpreted as a skill by players. Such skill, when overestimated, may lead to erroneous cognitions.

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Misinterpreting ‘winning' in multiline slot machine games

Candice Jensen et al.
International Gambling Studies, forthcoming

Abstract:
On multiline slot machines, ‘wins' often amount to less than the spin wager, resulting in a monetary loss to the gambler. Nevertheless, these losses disguised as wins (LDWs) are accompanied by potentially reinforcing audiovisual feedback. A concern for gambling behaviour is whether or not players categorize LDWs as wins or losses, as miscategorization could effectively increase the reinforcement rate of these games. The purpose of this study was to evaluate whether novice gamblers psychologically miscategorize LDWs. Forty-seven novices (undergraduate students) played 200 spins on an actual slot machine with credits, then estimated how often they won. It was found that the more LDWs players were exposed to, the higher their win estimates. In a subsequent ‘think out loud' playing session, the majority of novices also verbally miscategorized LDWs as wins. We conclude that LDWs could increase the reinforcement rate of these games, despite not increasing the payout to the gambler.

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The Effects of Sleep Debt on Risk Perception, Risk Attraction and Betting Behavior During a Blackjack Style Gambling Task

Daniel Frings
Journal of Gambling Studies, September 2012, Pages 393-403

Abstract:
Gamblers often gamble while experiencing fatigue due to sleep deprivation or cumulative sleep debt. Such fatigue has been shown to make decision makers behave more riskily. The present study aimed to test the role of two cognitive processes, risk perception and risk attraction, in this effect. Two hundred and two participants played twelve hands of a black-jack style card game while either fatigued or reasonably alert. Findings showed that both fatigued and alert participants rated higher risk bets as more risky than lower risk bets, suggesting risk perception was unaffected by fatigue. However, fatigued participants did not rate higher risk bets as less attractive than lower risk bets, and reduced the size of their wager to a lesser extent when objective risk increased. These findings are discussed in relation to the effects of fatigue on motivated tasks and the need for gamblers to be aware of the effects of fatigue.

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Prediction of economic choice by primate amygdala neurons

Fabian Grabenhorst, István Hernádi & Wolfram Schultz
Proceedings of the National Academy of Sciences, forthcoming

Abstract:
The amygdala is a key structure of the brain's reward system. Existing theories view its role in decision-making as restricted to an early valuation stage that provides input to decision mechanisms in downstream brain structures. However, the extent to which the amygdala itself codes information about economic choices is unclear. Here, we report that individual neurons in the primate amygdala predict behavioral choices in an economic decision task. We recorded the activity of amygdala neurons while monkeys chose between saving liquid reward with interest and spending the accumulated reward. In addition to known value-related responses, we found that activity in a group of amygdala neurons predicted the monkeys' upcoming save-spend choices with an average accuracy of 78%. This choice-predictive activity occurred early in trials, even before information about specific actions associated with save-spend choices was available. For a substantial number of neurons, choice-differential activity was specific for free, internally generated economic choices and not observed in a control task involving forced imperative choices. A subgroup of choice-predictive neurons did not show relationships to value, movement direction, or visual stimulus features. Choice-predictive activity in some amygdala neurons was preceded by transient periods of value coding, suggesting value-to-choice transitions and resembling decision processes in other brain systems. These findings suggest that the amygdala might play an active role in economic decisions. Current views of amygdala function should be extended to incorporate a role in decision-making beyond valuation.

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Abstract Mind-Sets and Social Comparison: When Global Comparisons Matter

Kathryn Bruchmann & Abigail Evans
Social Psychological and Personality Science, forthcoming

Abstract:
When evaluating personal performance, there is a propensity for people to rely more heavily on social comparison information from individuals than from aggregates, which is often more diagnostic - referred to as the Local Dominance Effect. The present research explored the possibility that under certain conditions, a global dominance effect may emerge; that is, in some circumstances people might rely more on average comparison information. Two studies investigated the influence of abstract mind-sets on the use of social comparison information. In Study 1, self-evaluations of participants who were given comparison information from both individual and aggregate sources while in an abstract mind-set were affected more by aggregate than individual comparison information - demonstrating a global dominance effect. Study 2 investigated how construal level influences the use of social comparison information and results indicated that when thinking abstractly, people shifted their attention to average comparison information.

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The influence of initial beliefs on judgments of probability

Erica Yu & David Lagnado
Frontiers in Cognitive Science, October 2012

Abstract:
This study aims to investigate whether experimentally induced prior beliefs affect processing of evidence including the updating of beliefs under uncertainty about the unknown probabilities of outcomes and the structural, outcome-generating nature of the environment. Participants played a gambling task in the form of computer-simulated slot machines and were given information about the slot machines' possible outcomes without their associated probabilities. One group was induced with a prior belief about the outcome space that matched the space of actual outcomes to be sampled; the other group was induced with a skewed prior belief that included the actual outcomes and also fictional higher outcomes. In reality, however, all participants sampled evidence from the same underlying outcome distribution, regardless of priors given. Before and during sampling, participants expressed their beliefs about the outcome distribution (values and probabilities). Evaluation of those subjective probability distributions suggests that all participants' judgments converged toward the observed outcome distribution. However, despite observing no supporting evidence for fictional outcomes, a significant proportion of participants in the skewed priors condition expected them in the future. A probe of the participants' understanding of the underlying outcome-generating processes indicated that participants' judgments were based on the information given in the induced priors and consequently, a significant proportion of participants in the skewed condition believed the slot machines were not games of chance while participants in the control condition believed the machines generated outcomes at random. Beyond Bayesian or heuristic belief updating, priors not only contribute to belief revision but also affect one's deeper understanding of the environment.

By KEVIN LEWIS | 09:00:00 AM