Ezra Klein helped inaugurate Vox, his new explanatory journalism venture, with a think piece  titled “How Politics Makes Us Stupid.” The essay, largely drawing upon the research of  Yale’s Dan Kahan and the Cultural Cognition Project, discussed how ideologically motivated reasoning affects the way individuals process information, provoked a substantial number of responses, including these from David Harsanyi and Will Wilkinson.  Among others, I was quite astounded by the claim that “the belief that many of our most bitter political battles are mere misunderstandings” is an idea that “courses through the Constitution,” but that’s a topic for another day.

Among those responding to Klein’s essay was Paul Krugman, who found it to present “a genuine intellectual puzzle.”  He wrote:

What Ezra does is cite research showing that people understand the world in ways that suit their tribal identities: in controlled experiments both conservatives and liberals systematically misread facts in a way that confirms their biases. And more information doesn’t help: people screen out or discount facts that don’t fit their worldview. Politics, as he says, makes us stupid.

But here’s the thing: the lived experience is that this effect is not, in fact, symmetric between liberals and conservatives. Yes, liberals are sometimes subject to bouts of wishful thinking. But can anyone point to a liberal equivalent of conservative denial of climate change, or the “unskewing” mania late in the 2012 campaign, or the frantic efforts to deny that Obamacare is in fact covering a lot of previously uninsured Americans? I don’t mean liberals taking positions you personally disagree with — I mean examples of overwhelming rejection of something that shouldn’t even be in dispute.

This gave Kahan quite a chuckle.  After “laughing [himself] into a state of hyperventilation,” Kahan penned a more serious response, pointing out how Krugman’s essay was itself evidence of how ” ideologically motivated reasoning is in fact perfectly symmetric with respect to right-left ideology.”  Explains Kahan:

The test for motivated cognition is not whether someone gets the “right” answer but how someone assesses evidence.

A person displays ideologically motivated cognition when, instead of weighing evidence based on criteria related to its connection to the truth, he or she credits or dismisses it based on its conformity to his or her ideological predispositions.

Thus, if we want to use public opinion on some issue — say, climate change — to assess the symmetry of ideologically motivated reasoning, we can’t just say, “hey, liberals are right, so they must be better reasoners.”

Rather we must determine whether “liberals” who “believe” in climate change differ from “conservatives” who “don’t believe” in how impartially they weigh evidence supprotive of & contrary to their respective positions. . . .

Kahan then goes on to explain how this hypothesis has been tested (in papers like this one), and how it shows that — contrary to Krugman’s “lived experience” — both right and left fall prey to motivated cognition.  Kahan continues:

That Krugman is too thick to see that one can’t infer anything about the quality of partisans’ reasoning from the truth or falsity of their beliefs is … another element of Krugman’s proof that ideological reasoning is symmetric across right and left!

For in fact, that “the other side” is closed-minded is one of the positions that partisans are unreasoningly committed to.