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The individual preference effect supplements the predominant group-level explanations for the failure of groups to solve hidden profiles. Even in the absence of dysfunctional group-level processes, group members tend to stick to their suboptimal initial decision preferences due to preference-consistent evaluation of information. However, previous experiments demonstrating this effect retained two group-level processes, namely (a) social validation of information supporting the group members’ initial preferences and (b) presentation of the additional information in a discussion format. Therefore, it was unclear whether the individual preference effect depends on the co-occurrence of these group-level processes. Here, we report two experiments demonstrating that the individual preference effect is indeed an individual-level phenomenon. Moreover, by a comparison to real interacting groups, we can show that even when all relevant information is exchanged and when no coordination losses occur, almost half of all groups would fail to solve hidden profiles due to the individual preference effect.

Making decisions is an integral part of everyday life. Social psychologists have demonstrated in many studies that humans' decisions are frequently and strongly influenced by the opinions of others--even in simple perceptual decisions, where, for example, participants have to judge what an image looks like. However, because the effect of other people's opinions on decision making has remained largely unaddressed by the neuroimaging and neurophysiology literature, we are only beginning to understand how social influence is integrated into the decision-making process. We put forward the thesis that by probing the neurophysiology of social influence with perceptual decision-making tasks similar to those used in the seminal work of Asch (1952, 1956), this gap could be remedied. Perceptual paradigms are already widely used to probe neuronal mechanisms of decision making in nonhuman primates. There is also increasing evidence about how nonhuman primates' behavior is influenced by observing conspecifics. The high spatial and temporal resolution of neurophysiological recordings in awake monkeys could provide insight into where and how social influence modulates decision making, and thus should enable us to develop detailed functional models of the neural mechanisms that support the integration of social influence into the decision-making process.

In two experiments, we provide evidence for a fundamental discussion asymmetry, namely, preference-consistent information sharing. Despite being in a dyadic situation requiring open information exchange and being given no incentive to do so, participants communicated more information that supported their individually preferred decision alternative than information that contradicted it. Preference-consistent information sharing was not caused by biased recall and occurred in written as well as in face-to-face communication. Moreover, we tested whether preference-consistent information sharing was influenced by statements by bogus discussion partners indicating that they held a congruent versus incongruent preference to the participants’ preference and that they understood versus did not understand the participants’ preference. We found that when partners stated that they understood the participants’ preference, subsequent preference-consistent information sharing was considerably reduced. This indicates that a motivation to be understood by others might be an important driving force underlying preference-consistent information sharing.

The presence of others in threatening situations can be a mixed blessing since it is not always perceived as supportive but can also impair well-being. Building on the social identity approach, we tested the idea that the presence of others has a buffering effect on neuroendocrine stress reactions only if a sense of shared social identity is evoked. Therefore, the salience of social versus personal identity was manipulated. To induce social-evaluative stress, the Trier Social Stress Test for groups (TSST-G) was employed, while in the control conditions the Placebo-TSST-G was used. As predicted, social identity salience attenuated the stress-induced cortisol reaction in the TSST-G condition. By contrast, there was no effect of identity salience in the Placebo-TSST-G conditions. These findings provide the first experimental evidence for the idea that being part of a group buffers neuroendocrine stress only if group members develop a sense of shared social identity.

One prominent finding in research on group judgment is that groups often outperform the average of their members’ individual judgments. Previous research attributed this finding to groups weighting their more competent members more strongly (differential weighting explanation). We postulate an alternative explanation, namely that groups outperform individuals due to group-to-individual (G–I) transfer, which denotes group members becoming more accurate individually during group interaction. In Experiment 1, we demonstrate that individual accuracy in an estimation task strongly increases due to interaction, leading to high accuracy at the group level. Experiment 2 replicates this finding and shows that G–I transfer can be enhanced by expertise feedback. In both experiments, when controlling for G–I transfer during group interaction, group judgments were not better than the average model. The findings imply that previously observed superior performance by groups compared to individuals may have been due to G–I transfer and not necessarily due to differential weighting.

Based on over 25 years of research on hidden profiles and information sharing in groups, and particularly our own work in this area, we outline a general model of how groups can achieve better decisions in a hidden profile situation than their individual members would have been capable of (i.e., synergy). At its core the model defines intensity and bias as the two key parameters that have to be optimised with regard to both the discussion of information and the processing of information in order to ensure synergy in group decision making. We review the empirical literature on information sharing and group decision making in the hidden profile paradigm (with a particular focus on our own studies) to illustrate how group decision quality can be enhanced by increasing intensity and decreasing bias in the discussion and processing of information. Finally we also outline why we think that the lessons learned from research using the hidden profile paradigm can be generalised to group decision-making research in...

Groups often fail to solve hidden profiles even when all information is exchanged. This is partly due to biased evaluation of information. We examined the effects of consensus information and task demonstrability on preference-consistent information evaluation and decision quality. The results showed that the evaluation of unshared but not shared information was moderated by consensus information and task demonstrability. For unshared information, majority members exhibited a higher evaluation bias favoring preference-consistent information than minority members. Task demonstrability reduced the evaluation bias only when group members received no information about the other members' preferences. Finally, majority members were less likely to solve the hidden profile than minority members, and this was partially mediated by the evaluation bias favoring preference-consistent unshared information.

The buffer hypothesis of the Job Demand-Control Model predicts that high levels of job control compensate for the negative effects of high job demands on well-being and health. Several studies have tested this hypothesis, but the results are far from consistent. The objective of this study was to test the buffer hypothesis with respect to psychological (subjective well-being) and physiological (salivary cortisol) indicators of job strain, using an experimental study design. Seventy-seven men and women worked at a simulated computer workplace for more than two hours. Job demands and job control were manipulated in a 2 (job demands: high vs. low)×2 (job control: high vs. low)×7 (time of measurement) study design. Demands were operationalized in terms of workload, and pacing control (self-paced vs. machine-paced) was used as a job control manipulation. As dependent variables, subjective well-being and salivary cortisol were measured at seven time points during the experiment (T1-T7). In line with the buffer hypothesis, high control eliminated the impact of high demands on salivary cortisol responses. The hypothesis was supported by a predicted significant three-way interaction of demands, control and time of measurement (p.001), qualified by the absence of significant effects of the independent variables at T1 and T2 due to lagged cortisol reactions, and significant two-way interactions of demands and control, as predicted by the model, at the five remaining times of measurement (T3-T7): high demands led to increased cortisol reactions only in the low control condition. In contrast, no main or interaction effects of the independent variables were found for subjective well-being. This discrepancy between physiological and psychological stress reactions might be due to the lack of specificity inherent in measures of subjective well-being, due to lagged psychological reactions, or due to self-report biases in the subjective measures. In sum, this study provides the first clear-cut experimental evidence for the idea that the negative impact of high job demands on endocrinological responses can be buffered by high levels of job control.

In 1999, van der Doef and Maes published a systematic review focusing on the Job-Demand–Control (JDC) model (Karasek, 1979) and the Job Demand–Control (-Support) (JDCS) model (Johnson & Hall, 1988) in relation to psychological well-being. Their review covered the period from 1979 to 1997. The present paper updates and extends this review. Covering research from 83 studies published between 1998 and 2007, our review revealed three major results: First, support for additive effects of demands, control, and social support on general psychological well-being is almost always found if the sample size is sufficient. Second, although there was consistent evidence for additive effects in relation to job-related well-being in cross-sectional studies, support rates were lower in longitudinal data. Thus, reciprocal or reversed causation might account for part of the association between JDC/JDCS dimensions and job-related well-being. Finally, evidence for interactive effects as predicted by the buffer hypoth...

Group members tend to be biased in their evaluation of the information discussed. The present study aimed to disentangle the effects of preference consistency, social validation, and ownership on information evaluation in a single experimental design. Participants first received information about a personnel selection task. After having made a decision, they read a transcript of a fictitious discussion. In the transcript, preference consistency, social validation, and ownership of information were orthogonally manipulated as within-subjects factors. As hypothesized, preference consistency, social validation, and ownership all increased the perceived quality of information. Furthermore, participants intended to discuss a larger proportion of their preference-consistent information than of their preference-inconsistent information. This discussion bias was significantly associated with the evaluation bias favoring preference-consistent information. These results provide the first empirical demonstration that the evaluation of information in groups is characterized by three distinct biases and that biased evaluation of information may contribute to biased discussion of information. Copyright © 2009 John Wiley & Sons, Ltd.

Previous investigations have shown that the perception of socially relevant facial expressions, indicating someone else's intention to communicate (e.g., smiling), correlate with increased activity in zygomaticus major muscle regardless of whether the facial expressions seen are directed towards the human observer or toward someone else (Mojzisch et al., 2006). These spontaneous, involuntary reactions have been described as facial mimicry and seem to be of considerable importance for successful interpersonal communication. We investigated whether specific neural substrates underlie these responses by performing a finite impulse response (FIR) analysis of an experiment using functional magnetic resonance imaging (fMRI) to investigate the perception of socially relevant facial expressions (Schilbach et al., 2006). This analysis demonstrates that differential neural activity can be detected relative to the FIR time window in which facial mimicry occurs. The neural network found includes but extends beyond classical motor regions (face motor area) recruiting brain regions known to be involved in social cognition. This network is proposed to subserve the integration of emotional and action-related processes as part of a pre-reflective, embodied reaction to the perception of socially relevant facial expressions as well as a reflective representation of self and other.

Zusammenfassung. Die Forschung zu eskalierendem Commitment beschäftigt sich mit der Frage, warum Personen an Handlungen bei fraglichem Handlungserfolg festhalten. Eine wesentliche Moderatorvariable eskalierenden Commitments formulierte Bowen (1987) mit der decision dilemma theory, derzufolge eskalierendes Commitment insbesondere dann stattfindet, wenn Informationen bezüglich des fraglichen Handlungserfolgs uneindeutig sind. Die bisherigen Studien zur decision dilemma theory stehen zum Teil für Alternativerklärungen offen und/oder weisen methodische Mängel auf. Die vorliegende Untersuchung stellt einen direkten Test der Theorie dar. Die Probanden sollten in einer Wirtschaftsfallsimulation eine Entscheidung über Folgeinvestitionen in eine Verluste schreibende Abteilung eines Unternehmens treffen. Zuvor waren die Probanden für eine Förderung dieser Abteilung entweder verantwortlich oder nicht verantwortlich gewesen. Zudem wurde manipuliert, ob sich Expertengutachten, die das Investitionsproblem behandelten, in der Mehrzahl für, gegen oder zu gleichen Anteilen für und gegen eine weitere Investition aussprachen. Wie von der decision dilemma theory vorhergesagt, zeigten die verantwortlichen Probanden insbesondere bei einer ausgeglichenen und somit uneindeutigen Gutachtenlage eskalierendes Commitment.

Being fed up with something is a prevalent and fundamental human experience. Although the relevance of mental satiation, that is, the process of becoming fed up with an action, is highly acknowledged in organizational psychology, almost no empirical research has examined this concept. In this article, we take a social cognitive neuroscience approach to mental satiation. By building on and extending the classic work of Lewin and Karsten, we propose a new model of mental satiation that focuses on the cognitive, motivational, and neural processes underlying mental satiation. Our model starts with the assumption that repeated performance of an action undermines one's need for competence and hence leads to a loss of intrinsic motivation. We then distinguish between two phases of the satiation process: The first phase is characterized by a loss of intrinsic motivation to perform the action. The second phase starts when the intrinsic motivation has vanished and volitional control is required to continue the action. We predict that the loss of intrinsic motivation in the first phase of the satiation process is correlated with a decrease in activity in brain regions associated with positive hedonic experience, such as the nucleus accumbens, the ventral pallidum, and the medial orbitofrontal cortex. In contrast, the growing aversion toward the action during the second phase of the satiation process is predicted to be correlated with an increase in activity in brain regions associated with unpleasant affect and volitional control, such as the amygdala, the anterior insula, and the anterior cingulate cortex.

We present a theoretical model that synthesizes and expands current explanations of the failure of decision-making groups to effectively use information that is distributed among their members. We propose that groups can outperform individual decision makers and voting schemes if certain asymmetries in information distribution are present and certain asymmetries in information processing are absent. How to achieve this we deduce from a review of the relevant literature. Finally, we discuss directions for future research and practical implications.

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations supportive behavior of other people as well as positive social relationships can act as powerful resources to cope with stress. In order to study the interplay between these variables, this protocol describes two effective experimental manipulations of social relationships and supportive behavior in the laboratory. In the present article, these two manipulations are implemented in the Trier Social Stress Test (TSST)—a standard stress induction paradigm in which participants are subjected to a simulated job interview. More precisely, we propose (a) a manipulation of the relationship between different protagonists in the TSST by making a shared social identity salient and (b) a manipulation of the behavior of the TSST-selection committee, which acts either supportively or unsupportively. These two experimental manipulations are designed in a modular fashion and can be applied independently of each other but can also be combined. Moreover, these two manipulations can also be integrated into other stress protocols and into other standardized social interactions such as trust games, negotiation tasks, or other group tasks.

The effect of diversity in individual prediscussion preferences on group decision quality was examined in an experiment in which 135 three-person groups worked on a personnel selection case with 4 alternatives. The information distribution among group members constituted a hidden profile (i.e., the correct solution was not identifiable on the basis of the members' individual information and could be detected only by pooling and integrating the members' unique information). Whereas groups with homogeneous suboptimal prediscussion preferences (no dissent) hardly ever solved the hidden profile, solution rates were significantly higher in groups with prediscussion dissent, even if none of these individual prediscussion preferences were correct. If dissent came from a proponent of the correct solution, solution rates were even higher than in dissent groups without such a proponent. The magnitude of dissent (i.e., minority dissent or full diversity of individual preferences) did not affect decision quality. The beneficial effect of dissent on group decision quality was mediated primarily by greater discussion intensity and to some extent also by less discussion bias in dissent groups.

In our lives, we face countless situations in which we are observed and evaluated by our social interaction partners. Social-evaluative threat is frequently associated with strong neurophysiological stress reactions, in particular, an increase in cortisol levels. Yet, social variables do not only cause stress, but they can also buffer the neurophysiological stress response. Furthermore, social variables can themselves be affected by the threat or the threat-induced neurophysiological stress response. In order to study this complex interplay of social-evaluative threat, social processes and neurophysiological stress responses, a paradigm is needed that (a) reliably induces high levels of social-evaluative threat and (b) is extremely adaptable to the needs of the researcher. The Trier Social Stress Test (TSST) is a well-established paradigm in biopsychology that induces social-evaluative threat in the laboratory by subjecting participants to a mock job-interview. In this review, we aim at demonstrating the potential of the TSST for studying the complex interplay of social-evaluative threat, social processes and neurophysiological stress responses.

In diesem Kapitel werden wir zunachst darstellen, unter welchen Bedingungen Dissens hilfreich ist. Anschliesend werden wir zeigen, was dialektische Fuhrungskrafte daraus fur sich ableiten konnen, also durch welches Verhalten sie Dissens fordern und nutzbar machen konnen.

Interpersonal cognitive consistency is a driving force in group behavior. In this paper, we propose a new model of interpersonal cognitive consistency in collective decision-making. Building on ideas from the mutual enhancement model (Wittenbaum, Hubbell, and Zuckerman, 1999), we argue that group members evaluate one another more positively when they mention information confirming each other's preferences instead of information disconfirming these preferences. Furthermore, we argue that this effect is mediated by perceived information quality: Group members evaluate one another more positively when they mention information confirming each other's preferences because they perceive this information to be more important and accurate than information disconfirming each other's preferences. Finally, we hypothesize that group members who communicate information confirming each other's preferences receive positive feedback for doing so, which, in turn, leads group members to mention even more of this information. The results of three studies with pseudo and face-toface interacting dyads provide converging support for our model.

In diesem Kapitel werden wir aktuelle Forschung zusammenfassen, die gunstige Effekte von Dissens demonstriert. Darauf folgend werden wir zeigen, welche Probleme durch Dissens entstehen konnen, um abschliesend zu verdeutlichen, dass sich Fuhrung folglich in einem Spannungsfeld der Forderung von Dissens und Konsens bewegen muss.

Klassische Forschung in Organisationen befasste sich nicht mit den gunstigen Folgen von Dissens, sondern ihrem Gegenteil, den ungunstigen Folgen von schnellem Konsens. Irving Janis untersuchte dieses Streben nach Konsens in Gruppen ausfuhrlich und nannte es Groupthink, in gewollter Ahnlichkeit zu George Orwells Kunstsprache Neusprech. Er entwickelte sein Modell anhand von Fallstudien dramatischer Fehlentscheidungen politischer Gremien, z. B. des Beraterstabs von US-Prasident Nixon in der Watergate-Affare. Laut Janis zeigt sich Groupthink anhand verschiedener Symptome. Beispielsweise haben die Mitglieder einer Gruppe zwar durchaus Zweifel an den Planen der Gruppe, sie ausern sie jedoch nicht, da jeder vermutet, der einzige Zweifler zu sein. Durch diese Selbstzensur verstarkt sich eine Illusion der Einstimmigkeit, also die Uberschatzung des tatsachlichen Konsenses. Ausert dennoch jemand eine abweichende Meinung, so wird Druck auf ihn ausgeubt. In den von Janis untersuchten 17 Fallen geht dieses Streben nach Konsens mit teils dramatischen Fehlentscheidungen einher, die Janis damit erklart, dass die Gruppen unter Groupthink in ihrer Informationsverarbeitung beschrankt sind. So legen sie sich schnell auf eine Entscheidungsalternative fest und vernachlassigen bei deren Bewertung abweichende Informationen. Auch aktuellere Fehlentscheidungen in Politik und Wirtschaft lassen sich moglicherweise zumindest zum Teil durch Groupthink erklaren, beispielsweise die Entscheidung der Bush-Administration fur den Krieg gegen den Irak.

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.

Although the effects of caffeine on basic cognitive functions are well-known, its effects on more complex decision making, particularly on option generation, is yet to be explored. We examined the effects of caffeine on option generation in decision making using everyday life decisional situations. In a double-blind placebo-controlled experiment, participants (N = 47) either received 300 mg of caffeine or a placebo. Participants had to generate choice options (things they could do) for a series of high and low familiar real-world scenarios and, subsequently, to decide among these options. Analyses revealed that participants in the caffeine condition generated significantly fewer options than participants in the placebo condition. Moreover, caffeine significantly reduced the option generation onset time, that is, participants in the caffeine condition generated their first option significantly faster than participants in the placebo condition. Regarding subsequent choice, we found evidence supporting the “take-the-first” heuristic, that is, the tendency to select the first generated option. This tendency was neither affected by caffeine nor by the familiarity of the scenarios. Caffeine results in fewer options generated in unconstrained real-life decision-making situations and decreases generation onset times.

The active learning hypothesis of the job-demand-control model [Karasek, R. A. 1979. "Job Demands, Job Decision Latitude, and Mental Strain: Implications for Job Redesign." Administration Science Quarterly 24: 285-307] proposes positive effects of high job demands and high job control on performance. We conducted a 2 (demands: high vs. low) × 2 (control: high vs. low) experimental office workplace simulation to examine this hypothesis. Since performance during a work simulation is confounded by the boundaries of the demands and control manipulations (e.g. time limits), we used a post-test, in which participants continued working at their task, but without any manipulation of demands and control. This post-test allowed for examining active learning (transfer) effects in an unconfounded fashion. Our results revealed that high demands had a positive effect on quantitative performance, without affecting task accuracy. In contrast, high control resulted in a speed-accuracy tradeoff, that is participants in the high control conditions worked slower but with greater accuracy than participants in the low control conditions.

Considering advice from others is a pervasive element of human social life. We used the judge-advisor paradigm to investigate the neural correlates of advice evaluation and advice integration by means of functional magnetic resonance imaging. Our results demonstrate that evaluating advice recruits the "mentalizing network," brain regions activated when people think about others' mental states. Important activation differences exist, however, depending upon the perceived competence of the advisor. Consistently, additional analyses demonstrate that integrating others' advice, i.e., how much participants actually adjust their initial estimate, correlates with neural activity in the centromedial amygdala in the case of a competent and with activity in visual cortex in the case of an incompetent advisor. Taken together, our findings, therefore, demonstrate that advice evaluation and integration rely on dissociable neural mechanisms and that significant differences exist depending upon the advisor's reputation, which suggests different modes of processing advice depending upon the perceived competence of the advisor.

Response to Minson and Mueller (2012) peerReviewed

Die meisten Fuhrungsansatze betrachten die Anpassung der Gefuhrten an die Fuhrungskraft als wesentliches Erfolgskriterium. Der hier beschriebene Ansatz der dialektischen Fuhrung beleuchtet hingegen die Probleme einer schnellen Anpassung der Gefuhrten fur die Qualitat von Entscheidungen. Die zentrale Aufgabe dialektischer Fuhrungskrafte besteht darin, Dissens (d. h. Meinungsverschiedenheit) bei Entscheidungsprozessen in Teams zu fordern. Der Ansatz basiert auf Forschungsbefunden, nach denen Dissens zu tieferer und ausgewogenerer Informationsverarbeitung fuhrt und dadurch kreativere Ideen und hochwertigere Entscheidungen hervorbringt. Vor dem Hintergrund zunehmend komplexer Probleme ist damit zu rechnen, dass dialektische Fuhrung in Zukunft relevanter wird. „Dialektische Fuhrungskrafte“ konnen das Auftreten von Dissens fordern, indem sie Teams aus extravertierten Mitgliedern unterschiedlicher Meinungen und Expertisen zusammensetzen, externe Experten zu Rate ziehen, Wechsel der Teammitglieder initiieren oder dialektische Entscheidungsmethoden (z. B. den Advocatus Diaboli) einsetzen. Damit abweichende Meinungen und Informationen in die eigene Sichtweise integriert werden und nicht zu Beziehungskonflikten fuhren, sollte die Fuhrungskraft dafur sorgen, dass eine vertrauensvolle Atmosphare im Team herrscht, sich alle Mitglieder gleichmasig an der Diskussion beteiligen und die vorhandenen Alternativen zwar kontrovers, aber anhand ubereinstimmender Zielkriterien diskutiert werden. Wahrend Dissens die Qualitat von Entscheidungen verbessern kann, ist bei der Umsetzung der Entscheidung Konsens wichtig, den die Fuhrungskraft durch Beteiligung aller Mitglieder aber auch durch charismatisches Verhalten fordern kann.

Results from 4 experiments demonstrate that learning the other group members' preferences at the beginning of a discussion impedes the solution of hidden profiles. In Experiments 1-3, participants who were not informed about their fellow group members' preferences were more likely to solve a hidden profile than those who received bogus information about the others' preferences. The negative effect of learning the others' preferences on decision quality was mediated by participants paying less attention to the information exchanged when they had been made aware of the others' preferences. Experiments 1 and 2 further ruled out that the effect of learning the others' preferences is due to participants bolstering their position or due to an increase in informational load. Experiment 3 showed that learning the other group members' preferences impedes the solution of hidden profiles even if one of the other members favors the correct alternative. Finally, Experiment 4 replicated these results in face-to-face interacting 3-person groups.

The present study aimed to investigate the impact of facial expression, gaze interaction, and gender on attention allocation, physiological arousal, facial muscle responses, and emotional experience in simulated social interactions. Participants viewed animated virtual characters varying in terms of gender, gaze interaction, and facial expression. We recorded facial EMG, fixation duration, pupil size, and subjective experience. Subject's rapid facial reactions (RFRs) differentiated more clearly between the character's happy and angry expression in the condition of mutual eye-to-eye contact. This finding provides evidence for the idea that RFRs are not simply motor responses, but part of an emotional reaction. Eye movement data showed that fixations were longer in response to both angry and neutral faces than to happy faces, thereby suggesting that attention is preferentially allocated to cues indicating potential threat during social interaction.

Entrapment occurs if people persist with losing courses of action. In two experiments, we show how elaborating social feedback (i.e., premature praise or forewarning regarding the chosen course of action) can have paradoxical effects on entrapment. The participants acted as head of a translation department and had to choose one out of four possible translation strategies for their employees. After choosing, they read four arguments (presumably written by former participants) which were either all in favor of the strategy chosen, all against it, or mixed. Half of the participants only read these arguments, whereas the other half elaborated on them by providing written comments (Experiment 1). The results showed that elaborating on other persons' arguments led to stronger entrapment, independently of whether the arguments were positive or negative. This pattern was due to biased argument processing: Whereas confirming thoughts were generated for positive arguments, negative arguments were refuted. Experiment 2 confirmed that this biased argument processing caused subsequent entrapment. These results indicate that elaborating any type of argument can lead to heightened entrapment and, hence, forewarning can backfire. Copyright © 2009 John Wiley & Sons, Ltd.

Social neuroscience has shed light on the underpinnings of understanding other minds. The current study investigated the effect of self-involvement during social interaction on attention, arousal, and facial expression. Specifically, we sought to disentangle the effect of being personally addressed from the effect of decoding the meaning of another person's facial expression. To this end, eye movements, pupil size, and facial electromyographic (EMG) activity were recorded while participants observed virtual characters gazing at them or looking at someone else. In dynamic animations, the virtual characters then displayed either socially relevant facial expressions (similar to those used in everyday life situations to establish interpersonal contact) or arbitrary facial movements. The results show that attention allocation, as assessed by eye-tracking measurements, was specifically related to self-involvement regardless of the social meaning being conveyed. Arousal, as measured by pupil size, was primarily related to perceiving the virtual character's gender. In contrast, facial EMG activity was determined by the perception of socially relevant facial expressions irrespective of whom these were directed towards.

When searching for information, groups that are homogeneous regarding their members' prediscussion decision preferences show a strong bias for information that supports rather than conflicts with the prevailing opinion (confirmation bias). The present research examined whether homogeneous groups blindly search for information confirming their beliefs irrespective of the anticipated task or whether they are sensitive to the usefulness of new information for this forthcoming task. Results of three experiments show that task sensitivity depends on the groups' confidence in the correctness of their decision: Moderately confident groups displayed a strong confirmation bias when they anticipated having to give reasons for their decision but showed a balanced information search or even a dis confirmation bias (i.e., predominately seeking conflicting information) when they anticipated having to refute counterarguments. In contrast, highly confident groups demonstrated a strong confirmation bias independent of the anticipated task requirements.

There is conclusive evidence that information search processes are typically biased in favor of the information seeker's own opinion (confirmation bias). Less is known about how knowledge about others' opinions affects this confirmatory information search. In the present study, the authors manipulated feedback about others' opinions and anticipation of group interaction. As predicted, the effect of knowledge about others' opinions on confirmatory information search depended on whether participants anticipated interacting with these others. Specifically, minority members anticipating a group discussion exhibited a particularly strong confirmation bias, whereas minority members who did not anticipate a discussion predominantly sought information opposing their opinion. For participants not anticipating group interaction, confidence about the correctness of one's decision mediated the impact of knowledge about others' opinions on confirmatory information search. Results are discussed with regard to the debiasing effect of preference heterogeneity on confirmatory information search in groups.

"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." [author's abstract]