BROOKE GLADSTONE:  This is On the Media. I'm Brooke Gladstone.

BOB GARFIELD:  And I'm Bob Garfield. We in the media often attribute a portion of Donald Trump’s election to “fake news,” and here I’m using the original meaning of that term, you know: Macedonian teens making bank on preposterous headlines, the Islamization of Texas, Pizza-shop child-sex conspiracies, that kind of baloney. Such fabrication, we worried, reverberated around the political echo chambers so resoundingly that our very democracy was imperiled or, you know, not.

Brendan Nyhan is a professor of government at Dartmouth College. Earlier this month, Nyhan, along with scholars Andrew Guess and Jason Reifler, published new research on the consumption of fake news during the 2016 campaign, and their conclusions undercut our most dire characterizations of the threat.

BRENDAN NYHAN:  Fake news wasn't as widely consumed as people think. At least when it comes to visiting fake news websites, as we define them in the study, only about one in four Americans actually did that, and that consumption was overwhelmingly concentrated among the 10% of people who have the most conservative online information diets.

BOB GARFIELD:  All right, you’re a college professor so, of course, let us define our terms. [LAUGHS] Fake news, how do you define it?

BRENDAN NYHAN:  The sites we classified as fake news websites had been identified by fact checkers as repeatedly publishing false or dubious information that was overwhelmingly in favor of one of the two presidential candidates. We excluded from that list sites that previously existed and had been identified as already covering hard news topics, so that includes sites like Breitbart and InfoWars, which existed prior to 2015 and 2016. So what we’re measuring here is not every dubious site on the internet. It’s, instead, people who are visiting these new sites that are publishing dubious content.

BOB GARFIELD:  Mm, do you have any reason to think that your conclusions would change had these pre-existing sites been factored in?

BRENDAN NYHAN:  No and, in fact, we show in an appendix to our paper, if you really want some exciting reading, that if you adjust for a couple of the, the borderline cases like Breitbart, the results are very similar.

BOB GARFIELD:  I was particularly interested in your methodology, which I read every word of and absolutely did not [LAUGHS] understand. Can you tell me what combination of outside data sets and your own surveys that you used to track the impact of fake news?

BRENDAN NYHAN:  This study is unique because we actually measure people's behavior in the real world. We surveyed a representative sample of Americans about a month prior to the 2016 presidential election and we also observed their anonymized online browsing behavior on laptop and desktop computers. These are people who have provided consent to have that information shared with the survey company, YouGov, and so we can actually observe the websites people go to.

BOB GARFIELD:  Now, there’s one gigantic hole in your study that you actually acknowledge, and that is you didn't measure the mobile Facebook traffic. Do you have any reason to think that if you had access to those data that the study would have come out the same way?

BRENDAN NYHAN:  I have no reason to expect otherwise, but it's important to note that we don't observe the pages that people go to on mobile, mobile browsers, and we don't observe what they do on the social media platforms, right, in particular within the Facebook app. It seems like we’d observe the same patterns that we see in our data but we, unfortunately, just can’t see it. And that’s a really important limitation to note. So you should think of our estimates as a kind of lower bound of, of fake news exposure.

BOB GARFIELD:  I want to get back to something you alluded to about the consumption of fake news, that the farther to the political right you were leading up to the election, the more likely you were to consume and even seek out fake news.

BRENDAN NYHAN:  We saw Trump supporters disproportionally consuming pro-Trump fake news and then, in particular, the 10% of people whose online browsing behavior was most skewed towards websites that disproportionately cater to conservatives also consumed the most fake news. It still represented a relatively small part of their political news diet though. These are people who consume a lot of political news, in general.

BOB GARFIELD:  But this consumption is so heavily weighted to the right-wing fringe, the notion of undecided voters being influenced by lies and democracy being subverted seems to me to be now very much in doubt.

BRENDAN NYHAN:  That's right. The prevalence of echo chambers is often overstated. Most Americans have a relatively neutral or balanced political information diet, so we might worry that exposure to fake news introduced misconceptions into our public debate, misinformed people but it's less plausible that exposure to fake news was changing the candidate people supported.

BOB GARFIELD:  Another finding that does track with a lot of postelection handwringing was Facebook's culpability, or at least let’s just say central role in the dissemination of the fake content.

BRENDAN NYHAN:  Facebook is the largest social media platform, and so the data indicate that Facebook was disproportionally the mechanism by which people were exposed to fake news. And we see that in two ways. The people who use Facebook the most were the most likely to be exposed to fake news but, we think even more convincingly, immediately prior to visiting a fake news website we see people having just visited Facebook in a way we don't see with Google, Twitter or webmail platforms like Gmail. So it seems like Facebook played a key role in allowing for fake news to spread. The reach and scope of that platform helped create a lucrative market that attracted fake news entrepreneurs from all around the world. The company has recognized that, to their credit, albeit belatedly, and is now trying to address it.

BOB GARFIELD:  All right, that sounds great although your study suggests that the people who consumed the fake news were duped and never looked for anyplace to get unduped.

BRENDAN NYHAN:  We can’t see in our data if people believed the fact checking articles they were exposed to, but what we do observe is that they almost never see a fact check of a specific claim on a fake news website that they’ve been exposed to. And, in fact, we rarely see people even googling after being exposed to fake news. So that presents a real challenge. You know, it's a lot to ask people to go check every claim they encounter online on their own. I don't think almost anybody does that. People are busy and they have other things going on in their lives.

BOB GARFIELD:  That is so dispiriting. If you get an email from a Nigerian prince that says that all you have to do is surrender your banking information and then they will send you [LAUGHS] $5 million, most people understand that if it's too good to be true it isn't true. When an ideological windfall comes your way through a Facebook share or something, why do you suppose people aren't equally skeptical?

BRENDAN NYHAN:  Partisanship does terrible things to our brains, Bob. I don’t, I don't know what else to say there. You know, look, some people were probably pretty skeptical. It's not that everyone took these claims literally, but enough people were being exposed to them and sharing them that they actually ended up reaching tens of millions of Americans in a way that wasn't previously possible.

BOB GARFIELD:  Brendan, as always, thank you very much.

BRENDAN NYHAN:  Thank you.

BOB GARFIELD:  Brendan Nyhan is a professor of government at Dartmouth College.