STEVE INSKEEP, HOST:
In this presidential debate season, we have research that may help you judge which politicians might be telling you the truth or not. NPR's social science correspondent Shankar Vedantam is here. And Shankar, what's the research?
SHANKAR VEDANTAM, BYLINE: Well, Steve, this is research by social scientists who are doing what social scientists do, which is they look for patterns in human behavior. Michael Braun, Lyn Van Swol, and Lisa Vang at Millikin University and the University of Wisconsin at Madison, they recently analyzed several hundred claims made by politicians that had been fact checked PolitiFact. This is a group that tries to assess...
INSKEEP: Sure.
VEDANTAM: ...Whether political claims are accurate or inaccurate. They find that politicians with inaccurate or untruthful statements as judged by PolitiFact are more likely to use lengthier sentences both in prepared speeches and in less scripted settings. So there's an old joke that says, Steve, do you know how a politician is lying? His lips are moving.
INSKEEP: (Laughter).
VEDANTAM: And this analysis seems to suggest there's some truth in that. The more the lips of the politicians in the study move, the greater the likelihood they were saying something that was inaccurate or untruthful.
INSKEEP: Oh, because they're just talking and talking and working their way around the inconvenient fact, perhaps.
VEDANTAM: So that's one theory. The researchers believe that verbosity in some ways might be a marker for deception because the person doing the lying is doing a lot to paint a picture that actually isn't true. It's worth pointing out here that different studies have produced different results on this, Steve, so context certainly matters. In analyses of online dating profiles, for example, people who lie about themselves have often been found to use shorter descriptions rather than longer descriptions. It could be because dating actually offers better fact checking. If you claim to be a rock climber but refuse to go rock climbing, you'll be very quickly found out.
INSKEEP: Yeah.
VEDANTAM: On the other hand, in a presidential primary debate, politicians might throw out several hundred claims, most of which are not going to get fact checked. So politicians who might actually have greater latitude to stretch the truth.
INSKEEP: Now I am thinking, Shankar, there might be occasions where someone gives you a very long answer because the truth is just plain complicated. How reliable is this system of checking for truthfulness?
VEDANTAM: I think that's an excellent question, Steve, because I think as with most things in human behavior, there's no one-size-fits-all rule that says if someone uses a long sentence they're lying. In many ways, I think it's better to think about this as being a flag. You know, it's like what cops do. If a police officer sees a car drifting across different lanes, it doesn't automatically mean the driver is drunk, but it's a flag that the driver might be drunk and might be worth pulling the driver over and giving him a breathalyzer test.
INSKEEP: Shankar, thanks very much.
VEDANTAM: Thank you, Steve.
INSKEEP: And we'll note this was a short interview.
VEDANTAM: (Laughter).
INSKEEP: Shankar Vedantam, who regularly joins us to talk about social science research and also explores the science of deception and self-deception on the podcast Hidden Brain. Transcript provided by NPR, Copyright NPR.
