partisan accelerator

Henry from Crooked Timber blogs about how partisan divergence in opinion on global warming is accelerating:

One bit of the Snyder, Shapiro and Bloch-Elkon paper that I linked to last week was overshadowed by the discussion of the Iraq war. They report survey evidence saying that:

Since September 11, there is not only a wider gap between Republicans and Democrats across a broad range of foreign policy issues, but their views have moved in opposite directions in response to new information. In 1998, 31 percent of Republicans believed that the planet was warming, but by 2006 only 26% did, whereas Democrats increased from 39 to 46% and Independents from 31 to 45%.

To my mind this suggests some interesting connections between new information, the dynamics of opinion change and partisanship. This same period saw an unmistakable convergence of scientific opinion, as many scientists who had previously been agnostic or skeptical came to accept mounting evidence that climate change was occurring. It also saw a clear convergence between Democratic voters and independents. But Republicans, if anything, would appear to have become less likely to believe strongly that climate change was happening during the same period. Either they weren’t getting the same information as scientists, Democrats and independents, or they were interpreting this information in different ways. My best guess (and I am not a public opinion specialist by any stretch of the imagination) is that two things are going on here. First, some Republicans are being exposed to different information than other voters, through talk radio, targeted mailings, frothing-at-the-mouth blogs and other media. Second, even those Republicans who aren’t (or who are only minimally exposed to this information) are increasingly coming to treat global warming as a partisan issue, where conceding that it is happening is in some sense giving ground to ‘the other side.’ [footnotes omitted]

I don’t think these can be treated as separate issues. Someone with a particular perspective shaped by unique surroundings, upbringing, life experiences, and choices will process a given bit of information differently than someone else with an entirely different perspective. People prioritize sources of information based on their existing perspectives. Sources of news and commentary don’t provide facts so much as narratives. So Republicans are both being exposed to different information than other voters and treating global warming as a partisan issue. So are Democrats; so am I, so are you. The process is circular and self-perpetuating. The filtered information and biased processor are two sides of the same coin. This is far from revolutionary.

But Republican intransigence on global warming is as the mewing of a small kitten compared to this:

[The Sunni insurgents] begin from a deep belief that they are the ones who defeated the United States (and they do believe that they are winning), and that they are a majority in Iraq (a few weeks ago I think I wrote about a statement by the head of the Islamic Army of Iraq which claimed that Sunnis made up 60% of Iraq's population). They also believe that the current Iraqi state and government are thoroughly controlled by Iran, and that the Shia are determined to ethnically cleanse them from (at least) Baghdad.

[Mark Lynch via Eric Martin]

One interesting question is: How do certain groups of people get so out of whack with broader society? Another is: What normally keeps groups from collectively going off the deep end like this? How are holdout narratives such as these (e.g., apartheid, anti-Semitism, divine right of kings) finally deconstructed and invalidated?