Thanks to Brian for offering to guest-blog this week. As I like to think about group epistemology, I will focus on the phenomenon of group polarization.
Group polarization, also known as the risky shift and the choice shift phenomenon, is a tendency of group deliberation to move individual group members toward the most fanatical--sometimes riskiest and sometimes most cautious--versions of the viewpoint they initially held. For example, after deliberation, people in groups opposed to the affordable care act are likely to be still more opposed; people who believe there are no salary inequities in an institution or company are likely, after discussion, to prevent investigations into its existence; people who think that smoking at universities is a serious problem are likely, after discussion, to insist on severe measures to prevent it. Group polarization shapes the conduct of individuals in universities, courts, juries and various other governmental institutions.
Cass Sunstein (1999) distinguishes between two different types of polarization pertaining to groups: group polarization toward within-group extremes and individual polarization toward within-group extremes. The latter but not the former is consistent with the group’s final collective opinion being no more extreme than the average for the group. Suppose all but one juror is ready to recommend life without parole for a suspect, whereas the remaining juror is leaning towards life with parole. The other jurors bring her around. In the envisaged scenario, the juror’s viewpoint has become polarized, whereas the viewpoint of jury stays more or less the same. It’s group polarization toward within-group extremes that we are primarily interested in here.
The initial research on group polarization was at first met with surprise and skepticism in the scientific community as it was at odds with the principles of group reasoning that were prevalent at the time. It was thought, for example, that group decisions would reflect an average of opinions and norms, which is quite intuitive for a group of like-minded individuals. You would expect like-minded individuals to find a compromise that reflects the mean position of the group. The result that overall group opinions move to extremes after deliberation is surprising and runs counter to common sense.
Despite the initial opposition, research in the area picked up in the 1960s, and group polarization was confirmed as a possible effect of groups on individual decision-making, even in trained decision-makers. Since the 1960s hundreds of studies have confirmed the phenomenon. Main and Walker (1973), for example, looked at decisions made by Federal district court judges sitting either alone or in groups of three and found that group discussions strongly influenced the judges’ decisions. Only about thirty percent of the cases where the judges were alone resulted in an extreme decision. When the judges were part of groups deliberation led to extreme results in sixty-five percent of cases.
In addition to the effect of groups on individual decision-making, it has been confirmed that groups as a whole move toward an extreme version of the initial opinions of the group. For example, appeal to group polarization is a common way of explaining jury decisions and political deliberation. Jury members tend to decide on punishment that is either significantly harsher or less harsh than those of any individual juror.
Fishkin and Luskin (1999) later discovered that group polarization is less likely to influence decision-making within highly diverse groups. The greatest effect on decision-making has been observed in groups of similar-minded individuals, particularly when the group is new or takes on new tasks.
Group polarization is not intrinsically bad. It might well be the psychological force required for individuals to take the right kinds of action. The problem with group polarization is that it is an unreliable method for forming true beliefs. Even if group polarization in a slut-walk protest might lead to new legislation preventing rapists from being acquitted on the grounds that the victim wore a miniskirt, which surely is a good thing, group polarization might just as often lead to an endorsement, or a lack of condemnation, of slavery, female circumcision, salary inequities or gun possession.
In my next post I will look at some reasons that polarization may occur.
Fishkin, J. S., & Luskin, R. C. (1999). “Bringing deliberation to the democratic dialogue”. In M. McCombs, A. Reynolds, & Eds. (Eds.), The poll with a human face: The National Issues Convention experiment in political communication (pp. 3-38). Mahwah, NJ: Lawrence Erlbaum.
Main, EC., Walker, TG. (1973). “Choice Shifts and Extreme Behavior - Judicial Review in the Federal Courts”, Journal of Social Psychology 91, 215-221.
Sunstein CR (1999) “ The Law of Group Polarization”, Harvard Law School December 1999 University of Chicago Law School, John M. Olin Law & Economics Working Paper No. 91
Sunstein CR (2002) “The Law of Group Polarization” Journal of Political Philosophy, Volume 10, Issue 2, pages 175–195.
Sunstein, CR. (2009). Going To Extremes: How Like Minds Unite and Divide, Oxford University PRess.
Sunstein, CR. (2009). On Rumors: How Falsehoods Spread, Why We Believe Them, What Can Be Done, Farrar, Straus and Giroux.