Hidden Profiles: A Brief History

In 1985, we challenged the idea that group decisions are more informed than individual decisions (Stasser & Titus, 1985). This idea had, and still has, intuitive appeal. After all, group discussion allows members to pool their disparate knowledge about decision alternatives. Thus, Jack and Jill considering which route to take up the hill can combine their knowledge of the obstacles and dangers of the various routes. Assuming that each knows some things that the other does not, their collective decision should be more informed than a decision make by either alone. Of course, this advantage to collective choice presupposes that Jill and Jack actually exchange their unique knowledge and that Jack listens to Jill and Jill listens to Jack. But why should they not listen to each other if they both want to get up the hill as safely? Seems reasonable, but our findings suggest that Jack and Jill would choose the route that was favored by their common knowledge-that is, the information they both knew before discussing the issue. Moreover, this common knowledge solution would likely persist even when their combined or collective knowledge clearly favored another route. Because Stasser and Titus (1985) falls in the category of an overlooked gem, we do not assume here that the findings are widely known. The study has attracted the attention of some, primarily those interested in team performance and group process, but probably is not common knowledge among the readership of Psychological Inquity. Thus, we describe the study and results in sufficient detail to set the stage for other points that this article addresses. Those other points address two questions. First, how did we have the insight or, perhaps more aptly, the luck to explore the impact of common and unique knowledge on group decisions? A related question that we have often pondered in retrospect is Why didn't someone else do it before we did? Unfortunately, we cannot answer this related question, but hindsight suggests that it was a study waiting to be done. The second question that we address is, What other empirical and theoretical work has been spawned or inspired by this study? Unfortunately, our answer to the second question must be brief and selective, omitting too much notable and sophisticated work by others. Hopefully, our answer, like a good book review, albeit not telling the whole story, will entice the reader to read more. For those wanting to read more, we suggest two recent chapters: Stasser (1999) and Stasser and Birchmeier (2003).