Political Polarization May Be A Consequence Of Similar Personalities Sorting Themselves Out Geographically

IN a recent post on the constitutionality of the filibuster, I floated the opinion “that polarization is due mainly to increasingly efficient sorting of American voters into parties according to personality type”, without offering any evidence or explanation, as several commenters were right to observe. I’m happy to admit that this is an idiosyncratic hypothesis, and that I therefore owe readers at least a sketch of the reasoning behind it.

First, conservatives and liberals do tend to differ in terms of personality. This is a well-known, well-confirmed proposition in political psychology. Among the “big five” personality traits, two are significantly associated with ideological sympathies. “Conscientiousness” is pretty much what it sounds like. Wikipedia helpfully notes that, “Recently, conscientiousness has been broken down, further, into two ‘aspects’: orderliness and industriousness, the former which is associated with the desire to keep things organised and tidy and the latter which is associated more closely with productivity and work ethic.”

Conscientiousness is positively associated with conservatism. The other politically-relevant personality trait, “openness to experience” is a bit harder to characterise, but “involves active imagination, aesthetic sensitivity, attentiveness to inner feelings, preference for variety, and intellectual curiosity.” Openness is positively associated with liberalism. It’s worth adding that one recent study found that another of the big five personality traits, “agreeableness“, also relates to our ideological tendencies, but this was detected only when agreeableness was broken down into two different components: “compassion”, which leans left, and “politeness”, which leans right. 

So, to summarise, if you’re low in “conscientiousness” and high in “openness”, you probably identify as liberal; if you’re high in conscientiousness and low in openness, you probably identify as conservative. One can also analyse ideological tendency using Jonathan Haidt’s “moral foundations theory“, but let’s just note for now that our political tendencies tend to flow from relatively fixed aspects of our personalities, which, by the way, have a significant genetic component

Second, as Bruce Bartlett argued recently, “The demise of the conservative Southern Democrat is the primary reason for the rise of political polarization.” I agree. In a recent post applying Mr Haidt’s theory to the question of re-unionization, I argued that in the middle of the 20th century.. 

the most temperamentally conservative people in America, pro-Jim Crow Southern whites, were a huge and indispensable part of the Democratic coalition. This required that the Democratic Party remain effectively conservative on social issues. As a consequence, not only could conservative Southerners feel comfortable in the party, but so could conservatives in the Northern, urban, industrial hotbeds of unionization.

As an increasingly liberal Democratic Party began to coalesce around the civil-rights agenda in the 1960s, conservative Southern Democrats trickled out of the party, and so did many conservative working-class whites in the North. But this is hardly the whole sorting story. Nelson Polsby, a Berkeley political scientist who died in 2007, emphasised the importance of air-conditioning. Here’s Mr Polsby in a 2002 interview:  

All right, now, what happened? Well, the Dixiecrats disappeared. Why did they disappear? … They disappeared because of the rise of the Republican Party in the South. Sooner or later, conservatives, instead of being Dixiecrats, became Republicans. Now why did they become Republicans? Well, because a sufficient number of people who were Republicans moved to the South from the North. And the question is, why did they move South? 

… And the answer is, they migrated down there. Why did they migrate down there? Well, basically, a fair number of them had spent winters down there, but with the introduction in the early 1950s of residential air-conditioning, people began to stay down there.

… Now, how did I verify this? Well, there is some demographic material, which seems to show this, and, also, of course, I went around and talked to some Southern Republican congressman. They told me some wonderful stories about how they had become Republican, or their parents had become Republican. And it was all about Northerners moving down and making it possible.

It would seem that this migration of Republicans to the South would have had the effect of increasing the concentration of dispositional conservatives in the South and, at the same time, increasing the concentration of dispositional liberals in the industrial North and the Mid-Atlantic. 

In his book “Who’s Your City”, Richard Florida and his colleagues found evidence that different regions and cities do have somewhat different personalities, which is what we’d expect if Mr Polsby was right. See this suggestive graphic

Where do the folks high in “conscientiousness” live? Where do folks high in “openness to experience” live? Given what we know about personality and politics, this pattern shouldn’t be at all surprising. (And I’d bet we’re seeing “compassionately agreeable” folks clustered in the upper Midwest, and “politely agreeable” folks clustered in the Southeast.) This is just a single snapshot, and doesn’t count as evidence of personality-based patterns of migration. But it does illustrate that personality type is not at all randomly distributed geographically, and I’d be quite surprised if the spread of air-conditioning and falling costs of relocation did not lead to a fair amount of sorting by personality type.   

Here’s the last piece of my sketch. Cass Sunstein’s work on group deliberation tell us that

… deliberation tends to move groups, and the individuals who compose them, toward a more extreme point in the direction indicated by their own predeliberation judgments. For example, people who are opposed to the minimum wage are likely, after talking to each other, to be still more opposed; people who tend to support gun control are likely, after discussion, to support gun control with considerable enthusiasm. … This general phenomenon — group polarization — has many implications for economic, political, and legal institutions…

I’ll say! We should expect increasingly politically homogeneous populations to settle on increasingly extreme consensus positions. My hunch is that, over time, Mr Sunstein’s group-polarisation dynamic has a self-reinforcing feedback effect. More uniformly conservative communities will drift toward more extreme conservative views. Remaining dispositionally liberal residents will feel increasingly isolated and alien, which will provide some with the impetus to “self-deport” to more ideologically congenial climes. And vice versa.  

I don’t know if all this adds up to a persuasive argument for the view that increasing political polarisation is due “mainly”, as I said, to the sorting of American voters into parties by personality. But I think it’s quite plausible that this is a significant part of the story.

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