Polarization and Groupthink

From "The Trouble With Elections: Everything We Thought We Knew About Democracy is Wrong," Chapter 11.6

Photo by Diana Mialik on Unsplash

In a deliberative situation, bringing additional perspectives, information and analytical styles to the fore has the potential to enrich the deliberation and lead to better-informed decisions. Diversity can be helpful in this active deliberation mode. On the other hand, when a group is seeking to find the correct answer to a question (in situations where a correct answer exists) many experiments have shown that avoiding active give-and-take deliberation —  keeping participants isolated from the assessments of other participants — is key to getting an optimal collective assessment. Thus, paradoxically, active deliberation can be both helpful and harmful, depending upon the specific task and circumstances.

First let me take up this less intuitive story-line, about the benefits of not engaging in give-and-take deliberation. In certain scenarios, this is the key to uncovering the “wisdom of crowds.” To explain this, it is helpful to briefly consider the discovery made by Francis Galton in 1906, as so wonderfully described by James Surowiecki in his book The Wisdom of Crowds. Galton was a Victorian scientific polymath who was a pioneer in many fields including statistics, psychology and eugenics. In the field of meteorology he devised the first weather map. Galton believed some people were born brilliant and most were not. In one famous experiment he sought to prove how badly the average person was at assessing matters they knew little about. He utilized the betting slips of a guess-the-weight-of-an-ox game at a fair, the annual West of England Fat Stock and Poultry Exhibition. Around 800 fair-goers, most of whom had no special knowledge, had guessed what the weight of an ox on display would be after slaughter and dressing. While some guesses were wildly high, and others wildly low, he was amazed to discover that the average of all of the guesses was 1,197 pounds, while the actual weight turned out to be 1,198 pounds! 

There are several possible explanations for this, such as that the poor guessers varied randomly on either side of the mark, tending to cancel each other out, allowing the few experienced, skilled butchers the chance to shine through. But the same general result shows up for guessing the number of jelly beans in a jar (a task nobody has a practiced skill for), and countless other similar tests in which there is a correct answer. The average of the group is generally better than the guess of even the most skilled among that group. A key factor in such wisdom-of-crowds scenarios is independence of the guessers. If those guessing hear the guesses of other people, that (poor quality) information tends to influence their own guess, and the average tends to fall further from the mark. People discount their own initial estimate in favor of what they come to believe is a more reasonable guess. In these sorts of situations the wisdom of the crowd is best discovered when individuals do not consult or communicate with each other.

The tendency of participants to latch onto the assessments of others is one cause of “groupthink.” There are multiple psychological reasons for this “herd” behavior. It can be uncomfortable to be at odds with the group. Psychologists have shown that most people (though not all) will adjust their assessments about such obvious factual questions as “which lines match” in a line-length matching game, and agree with the opinion stated by the rest of the group, even if the other members of the group are unambiguously wrong (having been secretly prompted by the experimenters to make outlandish decisions), just to avoid going it alone. Of course, people are also likely to cede independent judgment and go along with assessments expressed by high status individuals, leaders of one’s social/political/religious/ethnic group, or acknowledged experts. 

Even setting all of these psychological factors aside, there are also fully practical reasons for going along with the group. People often fall back on the heuristic that the opinion that most people hold is more likely to be right. If you come across a crowd of people all looking up into the sky, aren’t you likely to look up there too? 

An experiment that demonstrates such informational cascades that can lead reasonable people to wrong conclusions is described in Cass Sunstein’s important book, Why Societies Need Dissent. Imagine an urn filled with red and white balls in a specific ratio. The task is to guess whether there are more red or white balls. Each participant is allowed to withdraw one ball, examine it secretly, place it back in the urn, shake the urn to mix the balls up again, and declare their guess as to whether there are more red of white balls to the room full of other participants. It seems reasonable to assume that after enough people have done this it will become obvious which color is more numerous. 

But suppose that by chance the first two participants happen to draw red balls, even though there are more white balls in the urn. In this imagined scenario, the chances of this happening are less than 50/50 but still pretty good. Both participants have declared they think the urn contains more red than white. The third person secretly draws a white ball. Here is the crucial moment of an informational cascade. Remember, the participant doesn’t simply declare what color ball he or she drew, but makes an educated guess about which color is more numerous overall. This person may well still make the guess that there were more red than white balls, since all the evidence so far indicates a two-to one ratio. The fourth person may also happen to draw a white ball, but has heard the three previous participants declare that they think the urn is mostly red balls. So just like the third participant, it is reasonable for this person to guess the urn has mostly red balls. As the number of people guessing red mounts, any participant drawing a white ball will tend to discount this one small piece of personal knowledge in favor of the obvious overwhelming number of red balls he or she assumes everybody else is drawing. As Sunstein writes,

“people cease relying, at a certain point, on their private information or opinions. They decide instead on the basis of signals conveyed by others.” 

Market bubbles, and all kinds of other human foibles can be traced to this dynamic. In certain circumstances each participant would do better by making an independent assessment,  — making a guess based solely on personal knowledge (the color of the ball drawn) — without the influence of other people’s guesses. Surowiecki gives numerous examples in which independence of participant assessments are essential for optimum group decision-making through the wisdom of crowds. In these situations if participants discuss a topic among themselves, they may get pulled in one direction or another (perhaps by one participant’s status, eloquence, or other factor) and are likely to end up with a worse guess overall.

However, there are other sorts of issues where discussion and active deliberation (including the sharing of perspectives, analytical styles, or private information known by only a few participants) are important for making good decisions. This is sometimes referred to as collective intelligence as distinct from the wisdom of crowds discussed above. When crafting a proposal, or comparing a large number of options, these give-and-take procedures are essential. But Cass Sunstein and others have argued (and demonstrated) that active deliberation, with the give-and-take of information and arguments, in addition to the risk of groupthink, can instead lead to polarization. In some experiments, active deliberation has caused individuals who were originally closer to the entire group mid-point on some issue to move further towards the extremes of one side or the other. In other words, rather than discussion causing participants to come to a center of common ground, groups can polarize into more extreme opposing factions. But this is not inevitable. James Fishkin of Stanford University, found in his deliberative polls that this polarization dynamic does not occur. Perhaps this is because of the specific facilitation and “balanced information” his technique employs. The concerns that group discussion by participants would either result in deference to high status participants, or polarization into conflicting camps taking more extreme positions, may have remedies. Fishkin found that neither fear was realized in any of his deliberative polls, and in the first Chinese citizens’ assembly implementation there was a group movement away from the initial preferences of the higher status members. Fishkin credits this success to good design, with balanced presentations, moderated small group discussions, and secret “voting” in the exit poll.    

The danger of polarization that Sunstein warned against may be the result of societal tribalism or promoted by dynamics inherent in the process used. Policy discussion, or what passes for “debate” in a group may entail people raising hands to give their reasons and arguments in favor or in opposition to some policy. The side with more adherents often ends up with more active speakers (and crowd affirmations), causing undecided people to swing in that direction due to a variety of psychological tendencies. Those who are already for or against some policy will tend to selectively believe speakers who echo their own views due to confirmation bias. In such scenarios sub-group solidarity can indeed prompt polarization. A good deliberative process could assure that conflicting sides get an equal number of alternating speakers. 

However, due to conflicting values, or other deep beliefs, some issues may inevitably lead to polarized positions. So, voting is often required.¹ In some cases it may be appropriate for a mini-public crafting a proposal to report out competing policies for a final jury to judge. Likewise, even with the best possible process in place, active deliberation may result in a groupthink outcome that another mini-public (or the population as a whole) would soundly reject. This danger of groupthink is one reason why a mini-public that drafts a proposal, tapping into collective intelligence, should not be authorized to pass final judgment on their own proposal. An independent mini-public, which does not engage in give-and-take deliberation, but can benefit from the wisdom of crowds, with listening and weighing instead, needs to vote on final adoption.

1. But, what method of voting is optimal is a much more complicated question than most people recognize. There is no such thing as a perfect voting system that always feels fair, because the list of desirable features include mutually exclusive standards. Whenever there are more than two choices, every possible voting method can either be gamed through insincere manipulation voting, or result in pathological outcomes. It is beyond the scope of this book to examine voting methods used by mini-publics, but it is important to note that this is not a trivial question.