From WNYC in New York, this is NPR's On the Media.

I'm Bob Garfield.

And I'm Brooke Ladstone.

This week, we're talking about stuff we think we know about, but in fact, we don't know.

From our archives, we've pulled stories of debunkings of stories great and small

that have served as cultural signposts

sending us in the wrong direction. Some of these stories seem impervious to change because we

like them as they are. They make sense to us. They fit in with what we think we know. Brendan

Nyhan is a blogger and political scientist at the University of Michigan. Last year, he was part of a team that studied how people so easily ignore corrections to the record. One study tested a new way to blow past our inborn barriers, but it seems to have fizzled too. Brendan, welcome to the show.

Thanks very much.

Now, this study is building off previous research that you've done on correcting misperceptions.

Research, in fact, that we've covered on the show, but can you give us just a quick rundown of what those earlier experiments showed?

Sure.

My co-author, and I, looked at can the media effectively correct misperceptions, which seems like a simple question, but no one had really tested that scientifically.

And you found actually that when people had their misperceptions challenged, certain people at least were more likely to become more firmly entrenched in that belief.

That's right. People were so successful at bringing to mind reasons that the correction was

wrong, they actually ended up being more convinced in the misperception than the people who didn't

receive the correction. So the correction, in other words, was making things worse. So tell me about your latest study.

What we wanted to understand was whether it was possible to correct the misperception out there that Barack Obama is a Muslim, which has been shown to be held by 10 to 12 percent of the public.

And another 25 to 35 percent isn't sure if he is a Muslim or not.

So what we wanted to do was to see, is it possible to correct that misperception?

And something that we already knew is that you can't say Barack Obama is not a Muslim,

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