In the Atlantic, Robert Wright describes research that my team at Tufts University conducted in partnership with him. He summarizes the research question:

Suppose you’re a conservative or a liberal, and you’re watching a debate, and the debater you consider your ideological opponent throws in a “to be sure” sentence—a sentence that qualifies his or her basic policy position, underscoring some point of agreement with your ideological ally. Will that make you more favorably disposed to the person—more likely to take their views seriously, less likely to demonize them?

This was the method:

The study involved some 1,600 people, about half of whom identified themselves as liberal and half as conservative. Everyone watched an excerpt from one of two debates: one between Tim Noah and Glenn Loury on whether the minimum wage should increase, and one between Sarah Posner and Michael Dougherty on whether the government should be able to mandate that employer-provided health insurance cover contraceptives.

The excerpt shown to each viewer was short, but it clearly conveyed which person supported which position—in other words, who was the conservative and who was the liberal (on the issue in question, at least). For half of the viewers, the clip also included, at the end, a segment in which the speaker on the other side of the ideological fence from them added a to-be-sure.

Our conclusions:

The researchers at Tufts found that “viewing a concession created a more positive reaction to the ideological opponent.” Viewers who saw their ideological opponent make a concession were less likely than viewers who saw no concession to call their ideological ally the more credible of the two or the more knowledgeable of the two. And they were less likely to say they liked the ally more than the opponent.

Finally, Wright draws out two implications:

First, a message to people on the left and right who opine in public: Don’t forget to throw in a to-be-sure sentence; it may sound like a “concession,” but it could wind up helping your cause, especially if your cause includes not seeing America consumed by bitter acrimony. And it’s especially advisable to do this when you’re in “enemy territory”—when liberals are on Fox News, when conservatives are on MSNBC.

Second, it would be nice if the formats that mediate our discourse made it practical to add a to-be-sure sentence. For example, a pet crusade of mine is to change the structure of Twitter in a way that, while maintaining the 140-character limit on tweets, would nonetheless make it easier to add a short elaboration.