On Group Polarization

by F.

While I’m a big fan of the “infotopia” brought about by the blogosphere, Wikipedia, and Google, I sometimes get depressed by its dark side: lots of like minded people obsessed with getting information that merely confirms their biases. I see this in the comments to various blogs, even “good” blogs with large readerships of educated people. One of the reasons I’ve turned off comments on this one is that the vast majority of commentators are not worth listening to. Some are positively frightening (and I don’t just mean the comment spam I get about penis enlargement, viagra, and baldness nostrums). Many discussions in the blogosphere seem to me to be infected by what is called “group polarization.”

Cass Sunstien has a forthcoming paper (available on SSRN here) on deliberating groups versus prediction markets—how the former often fail and how the latter can possibly repair some of these failures. It’s worth reading, though because it’s an academic paper, it will be fairly hard for a normal person to get through—not because it’s “hard” but because it’s, well, academic in style and tone. I may post a full summary soon, but for now, here’s an appertif on group polarization.

You might think that deliberation is a good way to decide on an issue: we all get together and talk about the issue, pool our knowledge, and come to some conclusion. After all, isn’t that what democracy is all about? Well, it turns out that deliberation isn’t all it’s cracked up to be—not for some vague philosophical reason, but because of human psychology. Something strange happens when groups, especially ones comprising like-minded people, get together and discuss an issue: they all tend to take more extreme positions than they started with. Conservatives get more conservatives, liberals get more liberal, and so on. As Sunstein says:

Group polarization is the typical pattern with deliberating groups, and it has been found in hundreds of studies involving more than a dozen countries, including the United States, France, Afghanistan, and Germany.61 For example, those who disapprove of the United States and are suspicious of its intentions will increase their disapproval and suspicion if they exchange points of view. Indeed, there is specific evidence of the latter phenomenon among citizens of France.

Why? Three reasons, according to Sunstein:

  1. “People respond to the arguments made by other people—and the ‘argument pool’ in any group with some predisposition in one direction will inevitably be skewed toward that predisposition.”

  2. “People want to be perceived favorably by other group members. Sometimes people’s publicly stated views are, to a greater or lesser extent, a function of how they want to present themselves. Once they hear what others believe, some will adjust their positions at least slightly in the direction of the dominant position in order to hold onto their preserved self-presentation. They shift accordingly.”

  3. “…people with extreme views tend to have more confidence that they are right, and…as people gain confidence, they become more extreme in their beliefs. In a wide variety of experimental contexts, people’s opinions have been shown to become more extreme simply because their views have been corroborated and because they have been more confident after learning of the shared views of others.”

Sunstein goes on to suggest that prediction markets may cure group polarization problems, and I tend to agree. But regardless, another take-away seems to be that by merely seeking out similar views to your own, you aren’t doing yourself any favors—at least if you enjoy getting things right.