Biased information search in group decision making

Research has shown that people prefer supporting to conflicting information when making decisions. Whether this biased information search also occurs in group decision making was examined in three experiments. Experiment 1 indicated that groups as well as individuals prefer supporting information and that the strength of this bias depends on the distribution of the group members' initial decision preferences. The more group members had chosen the same alternative prior to the group discussion (group homogeneity), the more strongly the group preferred information supporting that alternative. Experiment 2 replicated these results with managers. Experiment 3 showed that the differences between homogeneous and heterogeneous groups reflect group-level processes. Higher commitment and confidence in homogeneous groups mediated this effect. Functional and dysfunctional aspects of biased information seeking in group decision making are discussed.     

The dissemination of critical,unshared information in decision‐making groups: the effects of pre‐discussion dissent

Previous research in group decision making has found that in situations of a hidden profile (i.e. the best choice alternative is hidden from individual members as they consider their pre‐discussion information), unshared information is disproportionately neglected and sub‐optimal group choices are highly likely. In an experimental study, three‐person groups decided which of three candidates to select for a professorial appointment. We hypothesised that minority dissent in pre‐discussion preferences improves the consideration of unshared information in groups and increases the discovery rate of hidden profiles. As predicted, consideration of unshared information increased with minority dissent. The expectation of an improvement of group decision quality was partially supported. In diversity groups (i.e. each member prefers a different alternative) consideration of unshared information and group decision quality was significantly higher than in simple minority groups. Results are discussed in the light of theories of minority influence. The benefits of using the hidden profile paradigm with minority and diversity groups for theory development in the area of group decision making are highlighted. Copyright © 2002 John Wiley & Sons, Ltd.     

Priming interdependence affects processing of context information in causal inference—But not how you might think

Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studies of both chronic and situationally-primed mindsets show that individuals with a relatively interdependent mindset (i.e., an emphasis on relationships and connections among individuals) are more sensitive to background contextual information than individuals with a more independent mindset. Two experiments tested whether priming cultural mindset would affect sensitivity to background causes in a contingency learning and causal inference task. Participants were primed (either independent or interdependent), and then saw complete contingency information on each of 12 trials for two cover stories in Experiment 1 (hiking causing skin rashes, severed brakes causing wrecked cars) and two additional cover stories in Experiment 2 (school deadlines causing stress, fertilizers causing plant growth). We expected that relative to independent-primed participants, those interdependent-primed would give more weight to the explicitly-presented data indicative of hidden alternative background causes, but they did not do so. In Experiment 1, interdependents gave less weight to the data indicative of hidden background causes for the car accident cover story and showed a decreased sensitivity to the contingencies for that story. In Experiment 2, interdependents placed less weight on the observable data for cover stories that supported more extra-experimental causes, while independents' sensitivity did not vary with these extra-experimental causes. Thus, interdependents were more sensitive to background causes not explicitly presented in the experiment, but this sensitivity hurt rather than improved their acquisition of the explicitly-presented contingency information.     

Social validation in group decision-making: Differential effects on the decisional impact of preference-consistent and preference-inconsistent information

Shared information has a stronger impact on group decisions than unshared information. A prominent explanation for this phenomenon is that shared information can be socially validated during group discussion and, hence, is perceived as more accurate and relevant than unshared information. In the present study we argue that this explanation only holds for preference-inconsistent information (i.e., information contradicting the group members’ initial preferences) but not for preference-consistent information. In Experiments 1 and 2 participants studied the protocol of a fictitious group discussion. In this protocol, we manipulated which types of information were socially validated. As predicted, social validation increased the decisional impact of preference-inconsistent but not preference-consistent information. In both experiments the effect of social validation was mediated by the perceived quality of information. Experiment 3 replicated the results of the first two experiments in an interactive setting in which two confederates discussed a decision case face-to-face with one participant.     

Effects of active information processing on the understanding of risk information

Two experiments investigated effects of active processing of risk information on participants' understanding and judgments. It was hypothesized that more active processing would lead to better understanding and differences in affective judgments (e.g. increased satisfaction and reduced perceived risk to health). In both experiments participants were given a written scenario about their being prescribed a fictitious medication. This medication was said to cause side effects in 2% of people who took it. Before answering a series of written questions, participants in the active conditions of both experiments were asked to carry out a reflective task (portraying the size of risk on a bar chart in Experiment 1 and answering a reflective question in Experiment 2). The results showed that active participants rated the likelihood of experiencing possible side effects significantly lower than passive participants (Experiment 1), and that active participants were significantly more satisfied with the information and judged perceived risk to health from taking the medication significantly lower than passive participants (Experiment 2). In both experiments, active participants were significantly more correct in their probability and frequency estimates. The studies demonstrate that active processing of risk information leads to improved understanding of the information given. This has important implications for risk communication. In the context of health, better understanding should lead to improved decision‐making and health outcomes. Copyright © 2004 John Wiley & Sons, Ltd.     

From thinking about what might have been to sharing what we know: The effects of counterfactual mind-sets on information sharing in groups

We hypothesized that the activation of a counterfactual mind-set minimizes group decision errors caused by the failure of groups to discuss unshared, uniquely held information. In two experiments, we manipulated the salience of counterfactual thoughts in a pre-task scenario and then had groups of three individuals discuss a murder mystery case. In both experiments, counterfactual mind-sets increased the discussion of unshared information and helped groups to identify the correct murder suspect. These results emerged regardless of whether the direction of the counterfactual thoughts was upward (Experiment 1) or downward (Experiment 2), suggesting that it is the process of thinking counterfactually, and not the content of the counterfactuals, that improves group decision making.     

Recalling semantic information about newly learned faces and voices

Several findings showed that semantic information is more likely to be retrieved from recognised faces than from recognised voices. Earlier experiments, which investigated the recall of biographical information following person recognition, used stimuli that were pre-experimentally familiar to the participants, such as famous people's voices and faces. We propose an alternative method to compare the participants’ ability to associate semantic information with faces and voices. The present experiments allowed a very strict control of frequency of exposure to pre-experimentally unfamiliar faces and voices and ensured the absence of identity clues in the spoken extracts. In Experiment 1 semantic information was retrieved from the presentation of a name. In Experiment 2 semantic and lexical information was retrieved from faces and/or voices. A memory advantage for faces over voices was again observed.     

Selective exposure to information: the impact of information limits

In research on selective exposure to information, people have been found to predominantly seek information supporting rather than conflicting with their opinion. In most of these studies, participants were allowed to search for as many pieces of information as they liked. However, in many situations, the amount of information that people can search for is restricted. We report four experiments addressing this issue. Experiment 1 suggests that objective limits regarding the maximum number of pieces of information the participants could search for increases the preference for selecting supporting over conflicting information. In Experiment 2, just giving participants a cue about information scarcity induces the same effect, even in the absence of any objective restrictions. Finally, Experiment 3 and 4 clarify the underlying psychological process by showing that information limits increase selective exposure to information because information search is guided by the expected information quality, which is basically biased towards supporting information, and information limits act to reinforce this tendency. Copyright © 2005 John Wiley & Sons, Ltd.     

Use of kind information for object individuation in young domestic chicks

In this paper, we studied the ability of newborn chicks to use kind information (sortal objects) provided by social and food attractors to determine the number of distinct objects present in an event (object individuation). Newly hatched chicks were reared with five imprinting objects and were fed mealworms. Chicks’ spontaneous tendency to approach the larger group of items was exploited. At test, on day 2 post-hatching, chicks observed two events in which objects, differing in kind, were each hidden behind one of two identical screens. Approaching either screen was considered a preferential choice. In Experiment 1, chicks presented with two social versus two food attractors did not exhibit any preference. In contrast, in Experiment 2, when chicks saw two different attractors (one social and one food) hidden behind a screen and one attractor hidden twice (i.e. moved back and forth two times) behind the other screen, they spontaneously approached the two different attractors rather than the single one seen twice. An explanation based on the preference for the more varied set was ruled out in Experiment 3: chicks did not preferentially choose between two different versus two identical objects when both groups were simultaneously presented. Results suggest for the first time that a non-human species uses kind information for individuating objects in a cross-basic-level contrast (i.e. food and social items) with minimal experience. As social and food stimuli differ in property as well as in kind information, the alternative explanation accounting for use of property information alone is also discussed.     

Commitment to a developing preference and predecisional distortion of information

People tend to distort their evaluation of decision-relevant information in favor of the currently preferred alternative. We test whether this predecisional distortion of information is amplified by increased commitment to that current preference. We manipulated commitment, without changing the preferred option’s content, by requiring participants to indicate their preference either by circling or by darkening a sizable box (cf. feature-positive effect). Experiment 1 revealed that the effort to darken substantially increased predecisional distortion. Experiment 2 ruled out elaboration as an explanation for the effect of darkening. Experiment 3 showed that, among participants who attributed the darkening effort to an external source, predecisional distortion decreased when the source was believed to summon effort. These findings suggest that the developing commitment to a tentatively preferred alternative is one driver of predecisional distortion.     

The effects of mental contamination on the hindsight bias: Source confusion determines success in disregarding knowledge

We present data from eight experiments in which we explored the effects of source confusion on the hindsight bias; participants' success in disregarding information when they were instructed to do so was affected by participants' level of source confusion. In Experiment 1 we demonstrated participants' failure to disregard Revolutionary War information they recently learned while reading an essay; this failure to discount was not affected by participants' essay reading times (Experiment 1a). In Experiment 2 participants successfully discounted obscure War of 1812 information; this discounted information remained available in memory (Experiment 2a). In a direct test of source confusion (Experiment 3) we showed that participants discriminated between presented and not‐presented War of 1812 information better than they discriminated presented and not‐presented Revolutionary War information. In Experiments 4 and 4a we tested and rejected a motivational explanation for our findings, namely that subjects voluntarily withheld information when asked to disregard it. We tested a debiasing technique in Experiment 5 and found it was successful in helping participants discount familiar information. Results throughout are discussed as being attributable to source confusion. Copyright © 2008 John Wiley & Sons, Ltd.     

The debiasing effect of counterfactual mind-sets: Increasing the search for disconfirmatory information in group decisions

We hypothesized that the activation of a counterfactual mind-set minimizes decision errors resulting from the failure of groups to seek disconfirming information to test an initial hypothesis. To test this hypothesis, we conducted two experiments examining the decision making processes of groups. The task for both experiments was modeled after the Space Shuttle Challenger disaster, and groups had to actively seek disconfirmatory information to make a correct decision. Prior to beginning the group decision making task, groups were exposed to one of two pre-task scenarios in which the salience of counterfactual thoughts was manipulated. In Experiment 1, groups in the counterfactual prime condition were significantly more likely to make the correct decision than groups in the non-counterfactual prime condition. In Experiment 2, we replicated the effect of counterfactual primes on decision accuracy and demonstrated that groups in the counterfactual prime condition were more likely to seek disconfirmatory information than groups in the non-counterfactual prime condition. We also conducted mediation analyses that clarify the decision making process. Implications for group decision making are discussed.     

Recalling semantic information about newly learned faces and voices

Several findings showed that semantic information is more likely to be retrieved from recognised faces than from recognised voices. Earlier experiments, which investigated the recall of biographical information following person recognition, used stimuli that were pre-experimentally familiar to the participants, such as famous people's voices and faces. We propose an alternative method to compare the participants' ability to associate semantic information with faces and voices. The present experiments allowed a very strict control of frequency of exposure to pre-experimentally unfamiliar faces and voices and ensured the absence of identity clues in the spoken extracts. In Experiment 1 semantic information was retrieved from the presentation of a name. In Experiment 2 semantic and lexical information was retrieved from faces and/or voices. A memory advantage for faces over voices was again observed.     

Post‐event information presented in a question form eliminates the misinformation effect

This study investigated the influences of sentence surface forms on the misinformation effect. After viewing a film clip, participants received a post‐event narrative describing the events in the film. Critical sentences in the post‐event narrative, presented in either a statement or a question form, contained misinformation instead of questions with embedded false presuppositions; thus participants did not have to answer questions about the original event. During the final cued‐recall test, participants were informed that any relevant information presented in the post‐event narrative was not in the original event and that they should not report it. Consistent with previous findings, Experiment 1 demonstrated that post‐event information presented as an affirmative statement produced the misinformation effect. More importantly, post‐event information presented in a question form, regardless of whether it contained a misleading or studied item, increased the recall of correct information and reduced false recall. Experiment 2 replicated the main finding and ruled out an alternative explanation based on the salience of misleading items. Post‐event information presented in a question form created a condition similar to that which produces the testing effect.     

The sampling of critical,unshared information in decision-making groups: the role of an informed minority

A collective information sampling model and observations of discussion content suggest that decision-making groups often fail to disseminate unshared information. This paper examines the role that a fully-informed minority may play in facilitating the sampling and consideration of unshared information. University students read a mystery and then met in four-person groups to discuss the case. When critical clues were unshared among three members before discussion, a fully informed fourth member (informed minority) promoted the discussion of these critical clues when participants thought the mystery had a demonstrably correct answer (solve set) but not when they thought the clue may have been insufficient to solve definitively the case (judge set). None the less, under both solve and judge sets, the informed minority increased the likelihood that the group would identify the correct suspect. Social combination, information sampling, and minority influence interpretations of the results are discussed. © 1998 John Wiley & Sons, Ltd.     

Can People Identify “Deceptive” or “Misleading” Items that Tend to Produce Mostly Wrong Answers?

In many domains, two‐alternative forced‐choice questions produce more correct responses than wrong responses across participants. However, some items, dubbed “deceptive” or “misleading”, produce mostly wrong answers. These items yield poor calibration and poor resolution because the dominant, erroneous response tends to be endorsed with great confidence, even greater than that of the correct response. In addition, for deceptive items, group discussion amplifies rather than mitigates error while enhancing confidence in the erroneous response. Can participants identify deceptive items when they are warned about their existence? It is argued that people's ability to discriminate between deceptive and non‐deceptive items is poor when the erroneous responses are based on the same process assumed to underlie correct responses. Indeed, participants failed to discriminate between deceptive and non‐deceptive perceptual items when they were warned that some of the items (Experiment 1) or exactly half of the items (Experiment 2) were deceptive. A similar failure was observed for general‐knowledge questions (Experiment 3) except when participants were informed about the correct answer (Experiment 4). Possibly, for these tasks, people cannot escape the dangers lurking in deceptive items. In contrast, the results suggest that participants can identify deceptive problems for which the wrong answer stems from reliance on a fast, intuitive process that differs from the analytic mode that is likely to yield correct answers (Experiment 5). The practical and theoretical implications of the results were discussed. Copyright © 2017 John Wiley & Sons, Ltd.     

Thinking straight while seeing red: the influence of anger on information processing

Because angry people apparently rely on heuristic cues when making judgments, anger has been claimed to trigger superficial, nonanalytic information processing. In three studies, the authors found that induced anger promoted analytic processing. Experiment 1 showed that angry participants were more likely to discriminate between weak and strong arguments than participants in neutral moods. Experiment 2 demonstrated that anger overrode dispositional preferences not to process, causing even those low in need for cognition to process analytically. Experiment 3 reconciled these findings with previous work by showing that angry people used accessible, valid, and relevant heuristics but otherwise processed analytically, as indicated by attitude change and elaboration data. Together, these experiments showed that angry people can have both the capacity and motivation to process and that their selective use of heuristics reflects the cue's perceived validity and not the failure to process analytically.     

Explicit awareness supports conditional visual search in the retrieval guidance paradigm

In four experiments we explored whether participants would be able to use probabilistic prompts to simplify perceptually demanding visual search in a task we call the retrieval guidance paradigm. On each trial a memory prompt appeared prior to (and during) the search task and the diagnosticity of the prompt(s) was manipulated to provide complete, partial, or non-diagnostic information regarding the target's color on each trial (Experiments 1–3). In Experiment 1 we found that the more diagnostic prompts was associated with faster visual search performance. However, similar visual search behavior was observed in Experiment 2 when the diagnosticity of the prompts was eliminated, suggesting that participants in Experiment 1 were merely relying on base rate information to guide search and were not utilizing the prompts. In Experiment 3 participants were informed of the relationship between the prompts and the color of the target and this was associated with faster search performance relative to Experiment 1, suggesting that the participants were using the prompts to guide search. Additionally, in Experiment 3 a knowledge test was implemented and performance in this task was associated with qualitative differences in search behavior such that participants that were able to name the color(s) most associated with the prompts were faster to find the target than participants who were unable to do so. However, in Experiments 1–3 diagnosticity of the memory prompt was manipulated via base rate information, making it possible that participants were merely relying on base rate information to inform search in Experiment 3. In Experiment 4 we manipulated diagnosticity of the prompts without manipulating base rate information and found a similar pattern of results as Experiment 3. Together, the results emphasize the importance of base rate and diagnosticity information in visual search behavior. In the General discussion section we explore how a recent computational model of hypothesis generation (HyGene; Thomas, Dougherty, Sprenger, & Harbison, 2008), linking attention with long-term and working memory, accounts for the present results and provides a useful framework of cued recall visual search.