The symbols of the Democratic and Republican parties on display in the District in 2008. (Karen Bleier/Agence France-Presse)

I never said all Democrats are saloon-keepers. What I said is that all saloon-keepers are Democrats. — Horace Greeley, 1860

For a long time I’ve felt that perceptions of polarization are a key contributor to political polarization. This was an underlying theme of the “Red State, Blue State” paper that I published with Boris Shor, Joseph Bafumi and David Park: People can become more polarized because they misunderstand who is voting for the Democratic and Republican candidates.

Douglas Ahler and Gaurav Sood write:

We document a consequential and heretofore undiscovered perceptual phenomenon in American politics and public opinion: Americans considerably overestimate the share of party-stereotypical groups in the mass-level parties. For instance, on average, people think that 32% of Democratic supporters are LGBT (6% in reality) and 38% of Republican supporters earn over $250,000 per year (2%). We experimentally demonstrate that these perceptions are genuine and party-specific, and not artifacts of expressive responding, innumeracy, or erroneous perceptions of group base rates. These misperceptions are relatively universal across partisan groups and positively associated with political interest. We experimentally document two political consequences of this perceptual bias: when provided information about the actual share of various party-stereotypical groups in the out-party, partisans come to see supporters of the out-party as less extreme and feel less socially distant from them. Thus, people’s skewed mental images of the parties appear to fuel contemporary pathologies of partisanship.

Elsewhere, Ahler writes:

A representative sample from California provides evidence that voters from both sides of the state’s political divide perceive both their liberal and conservative peers’ positions as more extreme than they actually are, implying inaccurate beliefs about polarization. A second study again demonstrates this finding with an online sample and presents evidence that misperception of mass-level extremity can affect individuals’ own policy opinions. Experimental participants randomly assigned to learn the actual average policy-related predispositions of liberal and conservative Americans later report opinions that are 8-13% more moderate, on average. Thus, citizens appear to consider peers’ positions within public debate when forming their own opinions and adopt slightly more extreme positions as a consequence.

The topic is important, because political polarization isn’t just about Democrats and Republicans in Congress, or even about the different policy positions of Democrats and Republicans involving taxes, health care, abortion, military spending and all the rest. Polarization is also contained in the views that Americans have regarding partisans of the other side — and for that, it’s helpful to have data, not just to know that many Democrats despise Republicans and vice versa, but that Americans have such factual confusion and are inclined to see each party as a collection of stereotypes.

Several years ago I tried to gather some data on perceptions of polarization. Some colleagues and I devised an online activity where people could guess what percentage of people from different groups voted one way or another. We gathered some data from a couple of hundred responses, but the results were so noisy we couldn’t really do anything with them.

So, in addition to appreciating this new work by Ahler and Sood, I also recognize the challenge of doing research in this important area.