Radio Lab: Into the Brain of a Liar We all lie — once a day or so, according to most studies. But a few of us make a habit of it. Researchers have found evidence of structural differences in the brains of people with a history of persistent lying.

Radio Lab: Into the Brain of a Liar

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It's MORNING EDITION from NPR News. Good morning. I'm Steve Inskeep.


And I'm Renee Montagne.

INSKEEP: Renee, truth or dare.


INSKEEP: When was the last time that you've told a lie?

MONTAGNE: You mean, like, a little white lie?

INSKEEP: No, I mean, a lie, like, really deceiving somebody?

MONTAGNE: Well, Steve, I don't know what you're insinuating but I can't say that I make a habit of it.

INSKEEP: Well, our next story is an investigation into the minds of people who do make a habit of lying, and it comes from NPR's science correspondent Robert Krulwich, who's been working in a space he calls Radio Lab.

Robert Krulwich, what is Radio Lab?

ROBERT KRULWICH: Well, Radio Lab is a place where we explore big ideas that make us rethink ourselves and the world around us.

MONTAGNE: And you're not alone in your radio lab, Robert.

JAB ABUMRAD: Nope, he's with me.

KRULWICH: This is Jab Abumrad. He's the creator of the show, co-host. And together we have been looking at liars.

Mr. ABUMRAD: Not ordinary liars. Like, not the you and me kinda liars but…

KRULWICH: Right, right. There are people who lie and lie and lie. Yeah.

Mr. ABUMRAD: Exactly.

Ms. YALING YANG (Researcher, University of Southern California): They just can't help it. They feel this impulse that they cannot control.

Mr. ABUMRAD: Yeah, the lie just tumbles out before they can stop.

KRULWICH: And this is who?

Mr. ABUMRAD: Oh, that's Yaling Yang. She's a researcher at the University of Southern California.

Ms. YANG: In the Department of Psychology Neuroscience

Mr. ABUMRAD: Now, Robert, here's what Yaling did. She gathered together a group of subjects, put them through a series of interviews, series of tests, and was able to identify a subset that seemed to lie more often, more persistently than average. And so she wondered, is it just their personalities, their upbringing or might there be something in their heads, in their brains, that could explain this line?

Ms. YANG: Basically we put people in the EMI scanner and then we scanned their brains.

Mr. ABUMRAD: She scanned all her subjects - the liars and the non-liars - no one knew which group they were in. And she was looking at a particular part of their brain called…

Ms. YANG: The prefrontal cortex. This is the part of the brain that processes information.

Mr. ABUMRAD: This is where the real thinking happens.

Ms. YANG: Making decisions and moral judgment, for example.

Mr. ABUMRAD: Now, if you zoom in to that place, just behind your forehead, what you'll see are two kinds of brain tissue. You've got gray matter and then you've got white matter.

KRULWICH: I've heard of gray matter.

Mr. ABUMRAD: Yes. Well, we think of the brain as being gray. But actually it's two things: it's gray and white. The gray stuff, you can kind of think of it as, like, the computer processor part.


Mr. ABUMRAD: It's these little clumps of neurons that process information. Like computer chips. That's the gray. Whereas the white…

Ms. YANG: The white matter is, like, the connections between all these computers.

Mr. ABUMRAD: The white matter, in other words, is what moves the thoughts around.

KRULWICH: Gray is where the thinking happens and then white is when you move the thought from here to there.

Mr. ABUMRAD: Exactly.

Ms. YANG: Yes. They transfer information from one end to the other.

Mr. ABUMRAD: Okay. So you've got your gray, you've got your white. What Yaling thought she would see when she looked into the brains of people who lie a lot…

Ms. YANG: I thought we would see a reduction.

Mr. ABUMRAD: Just some piece of it not there.

Ms. YANG: Yeah, they're missing something.

Mr. ABUMRAD: Physically she thought she would find less gray stuff, less of the thinking stuff.

KRULWICH: Why would… Why?

Mr. ABUMRAD: 'Cause that's what she's seen in other mental disorders that are kind of like this. And if you think about it in a really simplistic level, the gray is where you think your thoughts and it's also, among other things, where you crunch your moral calculation. And liars, she figured, have trouble in this department so maybe they have less gray. That was her notion.


Mr. ABUMRAD: But when she got the pictures back, what she saw was…

Ms. YANG: Such a great increase. It's…

Mr. ABUMRAD: More, and not the gray.

Ms. YANG: More white matter.

Mr. ABUMRAD: More white stuff, a lot more.

Ms. YANG: Twenty-five percent. Like, a quarter.

Mr. ABUMRAD: So they have 25 percent more connections in their heads than non-liars?

Ms. YANG: Yes.

Mr. ABUMRAD: Before we get to what that means, what were you thinking when you saw this?

Ms. YANG: I thought this was something.

Mr. ABUMRAD: Something.

Ms. YANG: Something.

Mr. ABUMRAD: Something. Here's her idea so far. Ready?


Mr. ABUMRAD: She thinks that these extra connections play a crucial role in a kind of in the moment storytelling. That's essentially what lying is, coming up with a story on the fly. Let me give you an example, okay?


Mr. ABUMRAD: You're leaving work, you're walking down the hall and you go into the elevator and an annoying, but nice, coworker corners you…


Mr. ABUMRAD: Corners you in the elevator.


Mr. ABUMRAD: Asks you out.

UNIDENTIFIED MAN: Um, you know, I've been meaning to ask: you maybe wanna go out with me on Friday?

Mr. ABUMRAD: So there you are. Questions dangling in the air. For most of us right at that moment inside our head and our brains, we're thinking, oh shoot. Say you're busy, say you're busy, say you're busy.


Mr. ABUMRAD: What are you busy with? Think of something. Think, think. Reaching out into the void trying to form a connection with some idea that can help you come up with some excuse.


Mr. ABUMRAD: You know, I could say…

UNIDENTIFIED WOMAN: Excuse me, I have a, shoot…I can't think of anything.

Mr. ABUMRAD: And really what you need to do at this moment is just take a bunch of disparate thoughts on different sides of your brain, like, me, tonight, teeth, dentist, and connect them all together.

UNIDENTIFIED WOMAN: I'm having some late-night dental work.

Mr. ABUMRAD: Like that.


Mr. ABUMRAD: We can all do it, given enough time. But for these people who lie a lot, she thinks that because they have so many more of these connections to begin with, they get there faster.

UNIDENTIFIED WOMAN: My mom is visiting that night; I'm meeting a friend for sushi; I am performing in a circus; Friday night book club; I have hockey practice; yoga; I have to polish the silver; I've got chemo…

Ms. YANG: The more connections…

UNIDENTIFIED WOMAN: …sorry, bee keeping…

Ms. YANG: The faster the speed of the processing. You can jump from one idea to another and you can come up with more random stories.

Mr. ABUMRAD: She thinks that in the brains of most of us we have trouble making those connections. We have…

KRULWICH: Would you have trouble if I said to you, like, come on, let's hang out on Friday night. Would you not be able to come up with a wowzer?

Mr. ABUMRAD: I would say, well, yeah, that…

KRULWICH: I have to count straws. See, Thursday night is straw counting, we always… We have about 316 straws so far and I'm only doing ones with the little red circles on them. So that's Thursday night, sorry.

(Soundbite of laughter)

KRULWICH: I don't know where it came from. It just happened.

Mr. ABUMRAD: There you go, see? You've got extra white matter, perhaps.

KRULWICH: So she's saying this is a cause of lying or an effect of lying. Like…

Mr. ABUMRAD: Well, she's not sure, and this is a big debate. What she can say is that children, as they grow…

Ms. YANG: Yeah, from age two to age ten, there is a big jump in their white matter. And that's actually the same age that they develop the skill to lie.

Mr. ABUMRAD: Yaling has a good reason to be thinking about how brains develop, because she's a new mom. Is this your first kid?

Ms. YANG: Yes, it's my first one.

Mr. ABUMRAD: Boy or girl?

Ms. YANG: A girl.

Mr. ABUMRAD: Doesn't make you wonder a little bit about what's going on inside her head?

Ms. YANG: Oh yes. I wonder about that all the time. It's still too early to scan her brain. But eventually I will do it.

Mr. ABUMRAD: Are you serious?

Ms. YANG: Yes.

KRULWICH: This is a moral to this. Never, if you're a little baby, have a social psychiatrist as a mother who would (unintelligible) very dangerous thing. Anyway, if she does this then maybe we'll know a little bit more about the nature and nurture of liars.

MONTAGNE: That's Robert Krulwich.

KRULWICH: She's not lying.

MONTAGNE: And Jab Abumrad.

Mr. ABUMRAD: And that's the truth.

INSKEEP: And they are part of Radio Lab, a production of WNYC.

MONTAGNE: For nothing but the truth on lying and the world of Radio Lab, go to

This is MORNING EDITION from NPR News. I'm Renee Montagne.

INSKEEP: And I'm Steve Inskeep.

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