Liberals often lament that conservatives are “deniers” of this-or-that scientific result, such as evolution or anthropocentric climate change.

And there is some truth to this charge. Many Americans who identify as conservatives do deny that most species today originated from earlier ones via natural selection of genetic mutations, or that human carbon emissions have anything much to do with the measured increase in average global temperature over the past century-and-a-half.

What liberals conveniently overlook, however, is that they can and do fall prey to denialism themselves.

Consider the following abstract of a new study published in the peer-review journal Social Psychological and Personality Science:

“We tested whether conservatives and liberals are similarly or differentially likely to deny scientific claims that conflict with their preferred conclusions. Participants were randomly assigned to read about a study with correct results that were either consistent or inconsistent with their attitude about one of several issues (e.g., carbon emissions). Participants were asked to interpret numerical results and decide what the study concluded. After being informed of the correct interpretation, participants rated how much they agreed with, found knowledgeable, and trusted the researchers’ correct interpretation. Both liberals and conservatives engaged in motivated interpretation of study results and denied the correct interpretation of those results when that interpretation conflicted with their attitudes. Our study suggests that the same motivational processes underlie differences in the political priorities of those on the left and the right.”

That’s just the abstract. Its innocuous description of the study’s result might not surprise, and certainly should not surprise. For it stands to reason that people are more likely to resist acknowledging scientific results when those results challenge other beliefs they cherish.

But the most interesting result of the present study itself is that liberals and conservatives are equally likely to be science denialists. The New York Post summarizes:

“The University of Illinois at Chicago researchers found the effects held steady regardless of issues at hand, which included hot-button topics like climate change, health care reform, nuclear energy, immigration reform, gun control and regulation on same-sex marriage.” 

If this study is sound, liberals should no longer be able to credibly present themselves as champions of “science” and “fact-based” policymaking over against obscurantist, knuckle-dragging conservatives who can’t handle the truth. Liberals could try to maintain that posture by challenging the study’s methodology or pointing out that it has not been replicated. And the study would certainly be worth broadening and replicating so that its results are themselves confirmed. However, given what we know generally know about the pervasiveness of confirmation bias, the study likely would be confirmed, but the confirmation itself would be unlikely to get a better reception than the original study.

Meanwhile, the broader lesson ought to be obvious. Being in the grip of ideology, regardless of its content, makes it harder to acknowledge truths that don’t fit within one’s ideology. The more extreme the grip or the ideology, the harder it is for the ideologue to admit even the possibility that some facts don’t thus fit. That’s a very good argument against being an ideologue.