G Group Processes & P Intergroup Relations I Article R Group Processes & Intergroup Relations 13(5) 653–671 © The Author(s) 2010 Beyond group-level explanations Reprints and permission: http://www. sagepub.co.uk/journalsPermission.nav for the failure of groups to solve DOI: 10.1177/1368430210369143 hidden profiles: The individual gpir.sagepub.com preference effect revisited Nadira Faulmüller,1 Rudolf Kerschreiter,2 Andreas Mojzisch,1 and Stefan Schulz-Hardt1 Abstract 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. Keywords group decision-making, hidden profiles, individual preference effect, preference-consistent evaluation of information, social validation Paper received 25 April 2009; revised version accepted 3 March 2010. Hidden profiles are group-decision tasks in which In the case of hidden profiles, shared and unshared the correct solution cannot be detected by an indi- information have different decisional implications, vidual group member prior to the group discussion, because each member possesses a subset of infor- 1 Georg-August-University Göttingen mation supporting an inferior decision alternative 2 Ludwig-Maximilians-University Munich (Stasser & Titus, 1985). This is due to the distribu- tion of shared and unshared information across indi- Corresponding author: Nadira Faulmüller, Georg-August-University Göttingen, viduals: shared information is available to all group Institute of Psychology, Economic and Social Psychology members prior to discussion, whereas unshared Unit, D-37073 Göttingen, Germany. information is uniquely held by one member only. [email: [email protected]] 654 Group Processes & Intergroup Relations 13(5) and the alternative implied by the unshared information (Gigone & Hastie, 1993). In the case of information is the correct one. Hidden profiles a hidden profile, this negotiation focus is likely to therefore represent the prototype of situations in lead to a premature consensus on a suboptimal which groups have the potential to outperform alternative, because the hidden profile distribu- individual decision-makers. Unfortunately, groups tion of information implies suboptimal individual typically fail to solve hidden profiles. In most cases, preferences at the beginning of the discussion they choose the alternative implied by their mem- and, therefore, the correct solution has hardly any bers’ shared information (for reviews, see Brodbeck, proponents in the negotiation process. Kerschreiter, Mojzisch, & Schulz-Hardt, 2007; Kerr & Tindale, 2004; Mojzisch & Schulz-Hardt, 2006; Stasser & Birchmeier, 2003). The individual preference effect Greitemeyer and Schulz-Hardt (2003) proposed Group-level explanations for the failure an alternative explanation for the failure of groups to solve hidden profiles, the individual pref- of groups to solve hidden profiles erence effect. They argued that even in the absence Two group-level processes have been proposed of any dysfunctional group-level processes, the to account for the failure of groups to solve hidden development of a suboptimal prediscussion pref- profiles: according to one explanation, groups do erence leads to biased evaluation of the informa- not discuss sufficient unshared information for tion exchanged during discussion: information the superiority of the correct solution to become supporting the group members’ prediscussion evident (Stasser, 1992). This dominance of shared preferences (preference-consistent information) is information has been attributed to the simple fact perceived to be of higher quality than informa- that shared information can be mentioned by tion contradicting those preferences (preference- each group member whereas unshared informa- inconsistent information). Because of this evaluation tion, by definition, is known by only one member bias, group members tend to stick to their initial and therefore cannot be discussed if this member suboptimal preferences even if all unshared fails to mention it (i.e., there is a probabilistic information is discussed and no premature group sampling advantage for shared information; consensus is reached. It should be noted that the Stasser, 1992). Other authors have traced the reason for this evaluation bias need not be some dominance of shared information back to the sort of defensive avoidance, that is, an intentional fact that shared, but not unshared, information distortion of information. Rather, a biased evalu- can be socially validated by other group members ation in favor of members’ prediscussion pre- during discussion (Parks & Cowlin, 1996). Social ferences could simply be a consequence of different validation refers to learning that others in the amounts of cognitive resources being alloca- group possess the same information and there- ted to preference-consistent versus preference- fore can attest to its accuracy. As proposed by inconsistent information: as outlined by Edwards Wittenbaum, Hubbell, and Zuckerman (1999), and Smith (1996), people might use the inconsis- social validation fuels a group’s tendency to repeat tency between their prior beliefs and the newly previously mentioned shared information. In learned preference-inconsistent information as a addition, there is evidence that social validation cue that either this information or their prior be- increases the perceived accuracy and relevance of lief could be false, and therefore instigate a more information which, in turn, increases the decisional detailed analysis of this piece of information. impact of information (Mojzisch, Schulz-Hardt, Conversely, the match of preference-consistent Kerschreiter, Brodbeck, & Frey, 2008). information with prior beliefs indicates that this According to the second explanation, group piece of information can be accepted without members primarily use the discussion to negotiate much further testing. As a consequence of the their preferences rather than to consider the relevant more intensive testing of preference-inconsistent Faulmüller et al. 655 information, group members are more likely of the two Greitemeyer and Schulz-Hardt (2003) to detect weaknesses in it, making preference- experiments, participants in the hidden profile con- inconsistent information appear to be of lower dition were less likely to detect the best candidate quality on average than preference-consistent than participants in the manifest profile condition. information (cf. Greitemeyer & Schulz-Hardt, However, these two conditions differed not only 2003). Empirical support for this idea can be found with regard to the participants’ initial preferences, in research on motivated reasoning (e.g., Ditto & but also with regard to which items were socially Lopez, 1992; Ditto, Scepansky, Munro, Apanovitch, validated in the discussion protocol: each time a & Lockhart, 1998) and the prior-belief effect (e.g., shared item was mentioned by a group member, Edwards & Smith, 1996). the protocol contained a passage about the other In the experiments by Greitemeyer and Schulz- members confirming that they held the same infor- Hardt (2003), participants first received incom- mation. Since most of the shared items supported plete information about a decision task which was the correct candidate in the manifest profile condi- either representative of the entire information set tion but an incorrect candidate in the hidden (manifest profile;1 Lavery, Franz, Winquist, & profile condition, preference consistency and social Larson, 1999) or was not (hidden profile). Next, validation of information were partially confounded. instead of discussing the decision case with each As research has demonstrated that social validation other, participants individually read a fictitious increases the perceived quality of information discussion protocol containing full information (Greitemeyer, Schulz-Hardt, & Frey, 2003; Mojzisch, exchange but with no group decision being reached. Grouneva, & Schulz-Hardt, in press; Mojzisch et al., They were asked to rate the importance, accuracy, 2008; Postmes, Spears, & Cihangir, 2001; Wittenbaum and valence of each piece of information and to et al., 19992), the failure of individuals to solve the reach a final individual decision. The results hidden profile could be a consequence of social vali- showed that few participants solved the hidden dation rather than a consequence of the participants’ profile. Preference-consistent information was initial preferences. In their second experiment, judged to be of higher quality than preference- Greitemeyer