The Southern Journal of Philosophy (ZOOS) Vol. XLN Groupthink versus The Wisdom of Crowds: The Social Epistemology of Deliberation and Dissent Miriam Solomon Temple University Abstract Trust in the practice of rational deliberation is widespread and largely unquestioned. This paper uses recent work from business contexts to challenge the view that rational deliberation in a group improves decisions. Pressure to reach consensus can, in fact, lead to phenomena such as groupthink and to suppression of relevant data. Aggregation of individual decisions, rather than deliberation to a consensus, sur- prisingly, can produce better decisions than those of either group deliberation or individual expert judgment. I argue that dissent is epistemically valuable, not because of the discussion it can provoke (Mill’s and Longino’s view about the benefit of dissent), but because dissenting positions often are associated with particular data or insights that would be lost in consensus formation. Social epis- temologists can usefully pay attention to various methods of aggre- gation of individual opinion for their effectiveness at realizing epistemic goals. 1. Introduction Philosophers from Plato to Mill to Popper to Rawls and Longino have made critical discussion and deliberation central to their social epistemologies. The claim is that rational dialogue between two or more individuals improves reasoning over what can be accomplished by individuals working alone. Longino (1990, 2002) even goes so far as to claim that objectivity is constituted by such critical discourse, provided that the discourse satisfies constraints such as tempered equality of intellectual authority, public forums for criticism, respon- siveness to criticism, and some shared standards of evaluation. Faith in the practice of rational deliberation is widespread and largely unquestioned. Moral and political philosophers depend on it as much as epistemologists and philosophers of science, often writing of “deliberative democracy” or “discursive democracy.” Characteristically, the Kantian focus on individual reason has been replaced by various ideals of group reason. For example, in Rawls’s “original position’’ a community of individ- 28 Groupthink versus The Wisdom of Crowds uals rationally deliberates along impartial guidelines (the “veil of ignorance”) in order to select shared principles of justice. In Habermas’s “discourse ethics,” participants rationally deliberate with one another from their actual social positions, attempting to reach consensus. Faith in the practice of rational deliberation extends to applied ethics as well as ethical theory. The following statement, from the University of Michigan Pediatric Ethics Committee, is typical of contemporary approaches: “What experimentation is to medicine, rational deliberation is to ethics.”’ While rational deliberation involves a community, rather than an individual working in isolation, the criticisms and responses to criticism are thought of as transparent to each reflective individual. Deliberation corrects errors, uncovers presupposi- tions, and sometimes transmits additional evidence. Each indi- vidual in the community is thought of as capable of recognizing their own errors and presuppositions when they are pointed out by others, and of accepting evidence discovered by others. This is a very ”internalist” view of deliberation, in a sense of the word “internalist” that is widely used among epistemol- ogists. (It is also somewhat individualist, despite the depen- dence on community, but that is not my topic here.) For example, Roderick Chisholm characterizes internalism this way: “If a person S is internally justified in believing a certain thing, then this may be something he can know just by reflecting upon his own state of mind” (Chisholm 1989, 7). The core of the position is that justifications for belief are internal to each individual knower and, typically, not only internal but also available to reflection. The contrast is with “externalism,” according to which one can be justified, or have knowledge, without being able to say why one is justified or has knowl- edge. Thus externalists claim that the reasons for justification or knowledge are not (or not readily) available to individual cognizers, either because the reasons do not enter conscious awareness or because the reasons (or causes) are external to individual minds. It might be thought that social epistemology is all exter- nalist, since by definition social epistemology concerns itself with epistemic phenomena that go beyond the individual. Nevertheless I maintain that this area of work (namely, on deliberation and criticism) in social epistemology is internalist in character, because the epistemic phenomena discussed are available to reflection and because when an epistemic phenome- non involves more than one individual (e.g., when one person points out problems in another’s work) the epistemic assess- ment is based on reflection by each and all of the individuals concerned. Again, the contrast is with externalism, in which epistemic assessments are not based on reflection or intro- spection at all. 29 Miriam Solomon This kind of internalism in social epistemology should not be confused with “conservative” social epistemology (as described by Hilary Kornblith [1994] and endorsed by him as well as Philip Kitcher [ 19931). “Conservative” social epistemology has more to do with individualism and with rejection of construc- tivism than it has to do with internalism. Generally speaking, work in social epistemology by philos- ophers has not been “internalist” in the way described above. Certainly Hilary Kornblith and Alvin Goldman are clear in their common position that social practices are to be evaluated instrumentally for their conduciveness to truth, rather than intrinsically for their rational cogency. For example, Goldman (2002) claims that infants get their first beliefs through a process he calls “BABA”: the bonding approach to belief accept- ability. Goldman suggests that beliefs are contagious when there is a prior bond of affection between individuals. It turns out that BABA is reliable, and the reliability of BABA is under- stood through evolutionary psychology: those with affective bonds will have less incentive to deceive one another than those without affective bonds. The epistemics of BABA are not trans- parent to reflection. I am basically in agreement with Goldman and Kornblith’s “externalist” approach (although I would describe myself as less conservative, in that I think that terms such as “justified” and “knows” are usefully applied to communities, in addition to individuals). In this paper, I am using the externalist (or instru- mentalist) perspective to look at group deliberation, discussion, and criticism. I do not assume truth in particular as the goal (as do Goldman and Kornblith), although all that I say is con- sistent with truth as a goal. I am also taking a thoroughly naturalistic approach, drawing on previous empirical work on epistemology of groups. It will turn out that the traditional “internalist” philosoph- ical picture of rational deliberation is a myth and not an episte- mologically useful myth (i.e., it is not an ideal toward which individuals or groups can or should strive). This is surprising because the practices of group rational deliberation seem so obvious: Helen Longino even says that her explication of objectivity in terms of the four criteria of knowledge comes from “an intuitive distinction between knowledge and opinion that I take to be shared .... Those who reject the conditions have a dif- ferent concept of knowledge, or perhaps, a concept of something else” (2002, 174). Surprises can be useful in epistemology. Epistemology is most helpful when it leads to normative recommendations that are surprising in that they are counterintuitive or in contra- diction with established practice. Furthermore, against the background of a few significant surprises, commonsense recom- mendations become more interesting because they cannot be 30 Groupthink versus The Wisdom of Crowds taken for granted. So it would make the enterprise of social epistemology more valuable to have some surprises, such as a counterintuitive recommendation or an unexpected negative consequence of commonsense normative practice. 2. Some Surprising Empirical Results A good deal of work in social epistemology is done in business schools, out of the philosophical limelight. This is perhaps because of the business school emphasis on outcomes, typically financial outcomes, in organizational research. This makes the work relevant to naturalistic epistemologists, especially those who evaluate epistemic practices instrumentally. Here are some surprising results: 1. Group deliberation often produces worse decisions than can be obtained without deliberation. (Often enough for epistemic concern.) 2. A group of nonexperts often produces better decisions on a topic than does an expert about that topic. (Thus challenging the traditional deference to the expert.) 3. If group deliberation does take place, outcomes are better when members of the group are strangers, rather than colleagues or friends. 4. Groups and organizations sometimes don’t know what they know.2 Let me say a little about each of the results, to give you the flavor of the research and the significance of the results. The “groupthink phenomenon was first described by Irving Janis in 1972.3 It occurs when a group of individuals aims to reach consensus on a controversial topic. Peer pressure,