Currently, issues of extremism and intransigence aren't just of academic interest—they're headline news every day. If anything, that strengthens the case for understanding those two issues, which makes a study released by Psychological Science very timely. A team of Duke University researchers has looked at the degree to which people feel their beliefs are superior and the degree to which they are dogmatic about their beliefs. The study found differences across the ideological spectrum, but it discovered that those with extreme beliefs share some things in common.

You might think that the sense that your beliefs are superior and a bit of dogmatism would go hand-in-hand, but the authors of the new study would be happy to point out where you'd be wrong. "Dogmatic statements tend to reflect the centrality of rigidity—the belief that one’s views could not (and should not) change from what they are currently," they note in their introduction.

In contrast, issues like certainty of beliefs and the sense that they're the only correct choice are more subtle things. For example, someone could take a look at the evidence available on a topic like climate science and decide that the same conclusion reached by almost every scientist who works in the field is correct. They could be very certain that their conclusion is correct and that it is superior—it's the only reasonable conclusion anyone could reach. But they wouldn't necessarily be dogmatic about it; they could also believe that their views should change if some new evidence was uncovered. They could also feel that their conclusion is superior because it is well researched but not feel confident in it because the research involved a lot of technical details.

In general, inflexibility about beliefs has been associated with conservative political thought. The political root of conservatism is a mistrust of change, and a variety of research has suggested that this political stance has deep-seated personality correlates. The authors cite research indicating that conservatives tend to score higher on personality tests that probe "dogmatism, intolerance of ambiguity, and closed-mindedness," while liberals tend to score well on tests that measure openness to new ideas.

To get at whether this was associated with a sense of superiority about these beliefs, the authors designed a series of questions that carefully separated them from dogmatism. They recruited over 500 US citizens through Amazon's Mechanical Turk and asked them about their position on some hot-button political issues like health care, immigration, abortion, taxes, and voter ID laws. Then, separately, they had them rate whether their beliefs on these issues were more (or less) correct than those of other people. Finally, the participants took a standard test of dogmatism, which had them rate statements like “Anyone who is honestly and truly seeking the truth will end up believing what I believe.”

As previous work had indicated, those who tended toward conservative political views tended toward dogmatism as well.

But things were different when people were asked to rate the superiority of their beliefs. If the superiority was graphed relative to the belief's position on the political spectrum, it produced a U-shaped curve. This indicated that those with the more extreme positions, whether liberal or conservative, tended to be more certain that their beliefs were better than everyone else's.

The other thing that was clear is that not all issues tend to produce a sense of superiority, and the smugness was not symmetrical. For example, while the role of government in health care is currently leading to a lot of extreme language, very few people anywhere on the political spectrum feel that their opinions are clearly superior to everyone else's; the same goes for voter ID laws. In contrast, liberals generally felt strongly that their beliefs on laws based on religion were superior, while conservatives weren't particularly bothered. For conservatives, the equivalent issue was voter ID laws. Two topics produced strong opinions on both extremes. One was the use of torture, although liberals favored their opinion much more strongly than conservatives. The converse was true for affirmative action.

When all matters were summed up, however, a clear trend was true: as the title of the paper puts it, feeling superior is a bipartisan issue. "Respondents who insisted that they had the only possible correct view were split evenly in terms of whether they endorsed conservative or liberal viewpoints," the authors conclude. And this held true despite a relative lack of dogmatism among the liberals.

The authors say that this sort of effect is likely to extend well beyond politics. Someone may be very confident about their political views, for example, but feel very uncertain about things like religion and sports. It also may be a cultural issue here in the US. Other cultures value personal modesty a great deal, which could limit the degree to which people in some countries feel that their beliefs are superior.

The one thing not noted in this study is that the results are the outcome of averaging hundreds of individual views. The actual business of politics is often driven by a limited number of outsized personalities, and those personalities may not be accurately captured by the average.

Psychological Science, 2013. DOI: 10.1177/0956797613494848 (About DOIs).