People are so conditioned to avoid contrary viewpoints that they will actually forego an opportunity to win more money if it requires them to read something with which they disagree.

That's according to a fascinating—and deeply depressing—study in the Journal of Experimental Social Psychology.

The study gave participants two options: they could read an article about same-sex marriage that matched their own perspective, or they could read an article about same-sex marriage that contradicted their views on the subject. They were told that if they selected the article with which they disagreed, they would be entered in a drawing to win $10. But if they selected the more comforting, self-affirming article, they would only stand to win $7.

"You'd think everyone would want to win more money, right?" wrote Vox's Brian Resnick in his write-up of the study. Resnick is right—I did think that.

As it turns out, a solid majority of participants—a whopping 63 percent—would rather read the article they already agreed with, even if it meant winning less money.

One of the study's authors, Matt Motyl, described this phenomenon as "motivated ignorance" in an interview with Vox. Participants were misinformed about the other side's arguments, and determined to remain that way. The emotional comfort they would lose by being exposed to contrary information was worth more to them than $4.

This has consequences for a democratic society, since it suggests that people do not tend to remain open to the best arguments for and against a certain policy. They willfully close their minds, because receiving contrary information is psychologically painful.

Of course, libertarian thinkers like Bryan Caplan and Ilya Somin have long argued that voters are rationally irrational: they make uninformed political decisions because the cost of becoming educated is too high relative to the ability to produce change—a well-informed voter still only gets one vote. The fact that people are perfectly willing to forego money in order to avoid the mental anguish that comes with processing new information fits well within a framework of rational irrationality.

If there's a policy consequence here, perhaps it's this: the bipartisan, decades' old effort to make the American government bigger and more powerful is placing a great deal of unwarranted trust in the collective wisdom of voters who, like children, prefer to place their hands over their ears and yell not listening!