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One benefit of working in groups is that group members can learn from each other how to perform the task, a phenomenon called group-to-individual transfer (G-I transfer). In the context of quantitative judgments, G-I transfer means that group members improve their individual accuracy as a consequence of exchanging task-relevant information. This improved individual accuracy allows groups to outperform the average of a comparable number of individuals, that is, G-I transfer leads to synergy. While there is mounting evidence that group members benefit from G-I transfer in quantitative judgment tasks, we still know rather little about what exactly group members learn from each other during this transfer. Here, we build on the distinction between metric knowledge (knowing what constitutes a plausible range of values) and mapping knowledge (knowing the relative magnitude of the targets) to gain further insights into the nature of G-I transfer. Whereas previous research found evidence that G-I transfer improves group members' metric knowledge, there is, so far, no evidence that group discussion also improves mapping knowledge. Using a multicue judgment task, we tested whether group members would benefit from G-I-transfer and, if so, whether this G-I transfer would manifest in the form of improved mapping knowledge. The results of two experiments suggest that this is the case. Participants who worked in real interacting groups outperformed participants who worked individually, and this increase in accuracy was accompanied not only by improved metric but also by increased mapping knowledge.

Recent research has shown that from early in development, children selectively form new beliefs in response to information supplied by others. However, little is known about the development of selective revision of existing beliefs in response to socially conveyed information. Such selective social belief revision has been extensively studied by social psychologists in the context of advice-taking. Here, we adapted the methods of this research tradition for studying selective advice-taking in young children and adults. Participants solved a perceptual judgment task, received advice, and subsequently made final decisions. The informational access (perceptual quality) of participants and advisor were experimentally manipulated. Adults revised their judgments systematically as a function of both their own and the advisor's informational access whereas children based their adjustments only on their own informational access. Two follow-up experiments suggest, however, that this pattern of results in children reflected performance rather than competence limitations: In suitably modified tasks, children did proficiently consider both their own informational situation and that of the advisor in their selective social belief revision.

When advice comes from interdependent sources (e.g., from advisors who use the same database), less information should be gained as compared to independent advice. On the other hand, since individuals strive for consistency, they should be more confident in consistent compared to conflicting advice, and interdependent advice should be more consistent than independent advice. In a study investigating the differential effects of interdependent versus independent advice on a judge's accuracy and confidence (Yaniv, Choshen-Hillel, & Milyavsky, 2009), advice interdependence was confounded with another variable, namely closeness of the advice to the judge's estimate. Interdependent advice was not only more consistent than independent advice but also closer to the judge's first estimate. The present study aimed at disentangling the effects of consensus and closeness of the advice by adding a third experimental condition in which interdependent (and, hence, consistent) advice was far from the judge's own estimate. We found that, as suggested by Yaniv et al., accuracy gains were indeed a consequence of advisor interdependence. However, in contrast to Yaniv et al.'s conclusions, confidence in the correctness of one's estimates was mostly a function of the advice's proximity to the participants' initial estimations, thereby indicating a social validation effect.

Six experiments investigated how the distance between one’s initial opinion and advice relates to advice utilization. Going beyond previous research, we relate advice distance to both relative adjustments and absolute adjustments towards the advice, and we also investigate a second mode of advice utilization, namely confidence shifts due to social validation. Whereas previous research suggests that advice is weighted less the more it differs from one’s initial opinion, we consistently find evidence of a curvilinear pattern. Advice is weighted less when advice distance is low and when it is high. This is in particular because individuals are much more likely to retain their initial opinions in the light of near advice. Also, absolute opinion adjustments towards the advice increases in a monotone fashion as advice distance increases. This finding is in contrast to the predictions of the theoretical framework previous studies on advice distance are based on, social judgment theory. Instead, they data are more in line with a simple stimulus-response model suggesting that absolute adjustments towards the advice increase with advice distance but—potentially—with diminished sensitivity. Finally, our data show that advice can be utilized even when it receives zero weight during belief revision. The closer advice was to the initial opinions, the more it served as a means for social validation, increasing decision-makers’ confidence in the accuracy of their final opinions. Thus, our findings suggest that advice utilization is a more complex function of advice distance than previously assumed.

Group discussions tend to focus on information that was previously known by all members (shared information) rather than information known by only 1 member (unshared information). If the shared information implies a suboptimal alternative, this sampling bias is associated with inaccurate group decisions. The present study examines the impact of 2 factors on information exchange and decision quality: (a) an advocacy group decision procedure versus unstructured discussion and (b) task experience. Results show that advocacy groups discussed both more shared and unshared information than free-discussion groups. Further, with increasing experience, more unshared information was mentioned in advocacy groups. In contrast, there was no such increase in unstructured discussions. Yet advocacy groups did not significantly improve their decision quality with experience.

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. Keywords: group decision making, decision quality, hidden profile, preference exchange, information pooling DOI: 10.1037/a0017627

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 disconfirmation 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. Keywords: information seeking; selective exposure; confirmation bias; group decision making; group confidence

Empirical evidence on selective exposure to information after decisions is contradictory: Whereas many studies have found a preference for information that is consistent with one's prior decision, some have found a preference for inconsistent information. The authors propose that different available information quantities moderate these contradictory findings. Four studies confirmed this expectation. When confronted with 10 pieces of information, decision makers systematically preferred decision-consistent information, whereas when confronted with only 2 pieces of information, they strongly preferred decision-inconsistent information (Study 1). This effect was not due to differences in processing complexity (Study 2) or dissonance processes (Study 3) but could be traced back to different salient selection criteria: When confronted with 2 pieces of information, the salient selection criterion was information direction (consistent vs. inconsistent), which caused a preference for inconsistent information. In contrast, when confronted with more than 2 pieces of information, the salient selection criterion was expected information quality, which caused a preference for consistent information (Study 4). Keywords: information seeking, selective exposure, information quantity, selection criterion, information direction