Who doesn’t love a good conspiracy theory? Liberals, that’s who. Take Princeton economist Paul Krugman who ominously warns that:

Unlike the crazy conspiracy theories of the left—which do exist, but are supported only by a tiny fringe—the crazy conspiracy theories of the right are supported by important people: powerful politicians, television personalities with large audiences.

Krugman makes a fair point: in moderation conspiracy theories may show healthy skepticism, but in excess they can erode the trust needed for states to fulfill their basic functions and warp the respect for evidence necessary for sound decision making.

Yet Krugman is mostly wrong that nuttiness is found mainly among conservatives, and his misperception actually reveals a great deal about U.S. politics. People of all political persuasions believe their views are objectively right and others hold positions that are arbitrary and asinine. Daniel Kahan finds that partisan commitments make people look for evidence to justify their conclusions. Even when, say, liberals come up with a correct answer, it may not have been because of their high esteem for evidence. They just got lucky. The implication is that people use data like drunks use lampposts: more for support than illumination. Columnist Ezra Klein concurs with Kahan, although he points out the large numbers of Republicans who refuse to accept climate science and wonders whether there is a liberal equivalent to climate change denial.

So are all Americans created equal when it comes to fearing collusion and conspiracies? Our recent research suggests that they are. As part of a 2012 national survey, we asked respondents about the likelihood of voter fraud as an explanation if their preferred presidential candidate did not win. Fifty percent of Republicans said it would be very or somewhat likely, compared to 44 percent of Democrats. This contradicts claims by Jonathan Chait that Republicans believe in electoral conspiracy theories far more than Democrats do.

Another 2012 national poll asked about fraud in specific presidential elections. Thirty-seven percent of Democrats believed that “President Bush’s supporters committed significant voter fraud in order to win Ohio in 2004,” compared to 36 percent of Republicans who believe that “President Obama’s supporters committed significant voter fraud in the 2012 presidential election.” Again, not much difference. This dovetails with Brendan Nyhan’s findings about “birther” and “truther” conspiracy theories. He found that Republicans were just as likely to believe that President Obama was born abroad as Democrats were likely to believe that 9/11 was an inside job.

In our survey, we also measured respondents’ underlying propensity to believe in conspiracy theories — that is, the general mindset that leads people to accept or reject conspiracy theories. We asked respondents whether they agreed with four statements:

  • “Much of our lives are being controlled by plots hatched in secret places,”
  • “Even though we live in a democracy, a few people will always run things anyway,”
  • “The people who really ‘run’ the country are not known to the voters.”
  • “Big events like wars, the current recession, and the outcomes of elections are controlled by small groups of people who are working in secret against the rest of us.”

We combined these questions into one summary measure. This graph shows the percentage of Democrats, Republicans, and independents that showed a strong or medium disposition towards thinking conspiratorially.

The upshot: near symmetry between left and right.

If Republicans and Democrats are equally prone to believing in conspiracy theories, where then is the liberal equivalent of climate change denial? An obvious possibility is the belief that Big Oil conspires to marginalize unfavorable findings or block alternative energies. Our survey, for example, shows that 52 percent of Democrats believe corporations are conspiring against us.

And just as climate science is unpalatable for conservatives, there are many lines of scientific inquiry uncomfortable to liberals, such as genetic modification or nuclear power. Research into risks and benefits of these technologies has been met with more suspicion by the left.

Moreover, the idea that American conservatives are peculiarly anti-science needs to be treated with caution. One study from the General Social Survey from 1974-2010 found that conservatives and regular church-goers began the period with the highest trust in science relative to liberals and moderates, and ended it with the lowest. But, science does not mean the same thing to all people. It can be seen as an abstract method, a set of institutions, or a rival to religion. It may be that American conservatives distrust science in part because they identify it with the regulatory state. When science means nuclear weapons, innovation and winning the space race, conservatives love it. And when they associate it with the EPA, regulation, and global institutions, they hate it.

So, being better informed about the science does not mean you will be more sympathetic to it. Kahan explains this in terms of “cultural cognition,” the tendency for values to influence risk perceptions. When you frame questions to separate out science comprehension from the expression of political identity, you find that comprehension of the science is actually pretty good—even among those who are against policies that would address climate change. People do not treat climate change as a question about the state of the science, but as a question about where they stand on climate change as a political and policy issue (see here, for example.) We have to wonder what would happen to liberals’ belief in climate science if the solution to climate change were freer markets and smaller government.

On balance, partisanship may influence which conspiracy theories we see, but not how often we are likely to see them. Neither liberals nor conservatives are more credulous or crazy. If both sides understood this, it might make it a little easier for them to work together.

Alfred Moore is a Research Fellow at the Centre for Research in Arts, Humanities and Social Sciences at the University of Cambridge, working on the Conspiracy and Democracy project. Joseph M. Parent and Joseph E. Uscinski are Associate Professors of Political Science at University of Miami and authors of American Conspiracy Theories.