Lilliana Mason is a Visiting Scholar at Rutgers University.

In media coverage of politics, most partisan conflicts tend to be described as a fight about something substantive. The October government shutdown was about Obamacare. The 2010 election was about government spending, perhaps. But even salient partisan battles aren’t entirely about specific policy questions. Party polarization is also a social process, where partisans are driven by a growing team spirit that is disconnected from policy considerations.

In their post Monday, Thomas Carsey and Geoffrey Layman discussed the power of our partisan identities to drive our policy attitudes. But as some of my recent research has found, our political identities can do a lot more than simply affecting our political beliefs.

I examined American National Election Studies data and found that partisan and ideological identities (and particularly the alignment between the two) are capable of powerfully driving what I call social polarization. This type of polarization is made up of three major effects, each of which occurs independently of our policy beliefs. No matter what we believe about policy, we are growing prejudiced against our opponents, more activist, and more emotionally volatile.

First, as our partisan and ideological identities grow stronger and more aligned (i.e. a liberal Democrat versus a conservative Democrat), we become more prejudiced against our partisan opponents. These effects have already been observed by social psychologists for many other kinds of identities. When we have strong and overlapping identities, we are biased against people who aren’t in our groups. We stereotype them, we dislike them, and we evaluate them unfairly. The stronger our identities, the stronger our response to inter-group rivalry. But I find that these processes operate for partisan identities as well.

Second, I find that strong and aligned political identities compel people into political activism, including attending political rallies, influencing other people’s votes, volunteering or donating to parties or candidates, and wearing a candidate’s button or sticker. Again, this effect is independent of people’s actual policy positions. We’re getting involved in politics mostly because we want our team to win, and only slightly to get the policy outcomes we like. Here as well, this result has been found by social psychologists studying other identities. For example, one study by Marga DeWeerd and Bert Klandermans found that when farmers felt strongly connected to their farmer identity they were more likely to participate in a political protest. The farmers who didn’t think of themselves as farmers had just as much to gain from protesting. But they didn’t have a strong identity to push them along.

Third, people with strong and overlapping political identities are much more likely to be angry at the opposing party’s presidential candidate during every presidential election. Even when strongly partisan and ideologically-sorted people don’t care much about political issues, they’re still a very angry group of people.

All three of these results come directly out of our psychological attachments to our social groups.  In short, what others have shown for other social groups hold for partisan groups as well.

Research in social psychology has found that when one of our social groups (say, Republicans) is in conflict with another group (Democrats), that group identity becomes more central to our idea of who we are. The more intense the competition between the parties, the more we respond to politics as members of partisan teams, not as citizens.

A threat to our group’s status also causes us to think, feel, and act defensively. We are hard-wired to feel like losers if our group loses, and to feel like winners if our group wins. We are also hard-wired to avoid feeling like losers if at all possible. When the prestige of one of our groups is under threat (something which happens constantly in partisan politics), we–often unconsciously–-lash out at our opponents. This is social polarization. We are a nation of partisans who are prejudiced against each other, active just for the sake of winning, and increasingly angry. We might believe that we’re responding to specific policy disputes, but to a very real extent we’re also being driven by an automatic, basic need to defend our social group.

To make things worse, when one social identity is aligned with another (i.e. Democrat and liberal), those identities grow stronger still. People with highly aligned identities have proved to be more intolerant, biased, and angry than those with cross-cutting identities, such as being a conservative and a Democrat. Unfortunately, in recent decades we have seen what political scientists call partisan sorting. Democrats have grown more liberal and Republicans have grown more conservative. The parties have also moved further apart on race and religion. In other words, America has gone from being a nation of cross-cutting political identities to a nation of highly aligned political identities. This further reinforces social polarization. Just by moving a few potent social identities into line behind our parties, we have made the competition between the parties more fierce, as partisans have more identities to defend in every political contest. Cue even more prejudice, activism, and anger.

Finally, my research has shown that political identities drive social polarization faster than they polarize our policy opinions. This leaves us with a nation of partisans who are acting like they disagree much more than they really do. And they’re doing it with all the rationality, reserve, and emotional composure of a rabid sports fan at a championship game. It doesn’t matter whether we agree or disagree, and it doesn’t really matter what the substance of the dispute is. We just want our side to win.

The more sorted and powerful our political identities become, the less capable we are of treating our political opponents with fairness and equanimity. Team victory eventually trumps the policy outcomes at the heart of governing. This means that no matter what the political debate of the day is officially about, it’s rooted in the partisan bias, eager action, and exaggerated anger that come directly out of our political identities.

Further Reading

This is the latest post in our ongoing series on political polarization. The previous posts are listed below.  -Dan Hopkins