MICHEL MARTIN, HOST:

It's been a week since a North Carolina man armed with a rifle traveled to a Washington, D.C., pizza restaurant. He says he was investigating online claims that Hillary Clinton and her campaign manager John Podesta were running a child sex trafficking ring from the basement of that restaurant. Now, these online claims are false and have been repeatedly debunked, but it got us wondering what would drive a person to believe wild stories like this, especially when there are so many facts that clearly disprove them.

So we called up Viren Swami, a professor of social psychology at Anglia Ruskin University in Cambridge in the United Kingdom. The psychology of conspiracy theories is among his research interests, and I started by asking him if there's a profile of the kind of a person who tends to believe in conspiracy theories.

VIREN SWAMI: There are a number of psychological traits that we have found to be associated with belief in conspiracy theories. I would suggest that profiling the conspiracy theorist is going to be quite difficult because, A, there are a range of different conspiracy theories, and B, I think the conspiracy narrative itself is believed by so many people that to come to a profile that fits everyone just wouldn't be possible.

MARTIN: How is this different from people who are just, say, bigots - you know, who just adhere to certain fixed beliefs about certain people?

SWAMI: I think they can be separate. I think there are some times when they may be inherently linked. But I think they're very different narratives, and they're very different belief systems. I think one of the things about conspiracy theories is - particularly in the United States is that nationally representative surveys suggests that up to about 50 percent of the population believe in at least one conspiracy theory. And there aren't any clear ideological divides. So you find conspiracist ideation among the left wing, among the middle ground, among the right wing.

Now, the content of the conspiracy theories might differ. So a common right-wing conspiracy theory would be the Obama birther conspiracy theory, whereas a left-wing conspiracy theory might be this idea that the financial crisis was intentionally caused in order to extend the power of the Federal Reserve.

So the content might change, but the prevalence of it doesn't seem to differ whether you're left-wing or right-wing. I think some people who believe in conspiracy theories believe in those ideas because it restores a sense of agency. It gives them a sense of power. It gives them a sense that they can do something about the world.

Now, one of the things we find quite consistently is that people who believe in conspiracy theories tend to be alienated, tend to be divorced from mainstream politics.

MARTIN: The New York Times in reporting on this recounts a recent poll conducted by Fairleigh Dickinson University that says that 63 percent of registered American voters believe in at least one political conspiracy theory.

Now, why might that be, particularly in a country like the United States where people really pride themselves on being optimistic and can-do? Why would that be such a pervasive part of the character of our politics?

SWAMI: I think there are going to be lots of different explanations for that. I think one explanation would center on the basis that a huge swathe of the American population feel disaffected, feel alienated. They don't feel like big politics represents them.

One of the other things I think - as an outsider looking in at American politics, I think one of the big changes we've seen is the use of a conspiracy narrative as a means of mobilizing people.

So Trump and the people around him are using a conspiracy narrative in my view to - not just to kind of have an argument with people but actually to mobilize people, to use it as a way of getting people involved in a campaign. And I think that was one of the big changes for me. I don't think historically it's incredibly rare to see that actually happen.

MARTIN: I'm wondering if what your take is on the effect of the Internet on this propensity to believe conspiracy theories. I think that one might assume that access to more information would attenuate this because people can easily find out that what they think is true is not true or that there are countervailing facts. But it doesn't seem to work that way.

SWAMI: Human beings have a very natural tendency to take in information that fits their own perspective of the world. And we tend to reject information or reject evidence that we disagree with. And we do that for a very simple reason. We don't like it when we feel wrong. We don't like it when people tell us we're wrong because that damages our psychological well-being. We don't like thinking that our view of the world, our perspective of the world is incorrect.

So what tends to happen is that we look for information; we look for evidence that fits what we already know or what we already believe, and we try to avoid information or evidence that we either disagree with or that we know doesn't fit with our perspective. And if someone comes along and says, here's the evidence, your natural tendency's actually to rehearse arguments against that evidence.

MARTIN: So what does one do? I mean what does one do because people who are in the information-disseminating business as you are and as we are, frankly, tend to believe that, you know, the facts matter and that this is important and that if you continue to kind of repeat the truth, that that somehow drives out the false narrative. That doesn't seem to be the case, so is there another way we should be thinking about this?

SWAMI: I think the first thing I would say is that we need to teach people and teach everyone how to be better critical thinkers, how to use information, how to understand pieces of information and how to look at information and work out whether it's good or bad information. That for me is the first step. But I don't think that's going to be enough.

I think if you kind of go along with this idea that conspiracy theories are more likely to emerge when people feel disaffected, when people feel alienated, then the natural outcome of that - the natural answer to what we should do is that we should be promoting greater democratic access. We should allow for everyone to be part of a democratic process in which they have a say, in which they have a voice. And once you start to have that, I think you will start to see the conspiracy theories start to diminish.

MARTIN: That's Viren Swami. He's a professor of social psychology at Anglia Ruskin University. That's based in Cambridge in the United Kingdom. Thank you so much for speaking with us.

SWAMI: Thank you. Transcript provided by NPR, Copyright NPR.