Deception
Two Cues That Will Give a Liar Away
New research shows how lying eyes and smooth talk can reveal who’s lying.
Posted October 19, 2024 Reviewed by Kaja Perina
Key points
- The issue of detecting deception continues to be a challenge for research on communication.
- New research distinguishes between the liar who wants to lie and the liar who wants to hide the truth.
- By taking someone’s motives into account, you can find a clearer path to honest communication.
The ability to detect deception is basic to virtually all human communication. You want to believe that people are being honest, from the stranger you stop on the street to ask for directions to your romantic partner whose opinion you ask for on your latest haircut. What, in their responses, could cue you in on the fact that you’re not being told the truth?
The psychology of lie detection has a long, complicated, and not necessarily successful past. Researchers who start with the assumption that “everyone lies” often run into dead ends when they seek the validity of such nonverbal hints as eye gaze, facial expression, and body posture. The words liars use also provide a source of potential information, including the length of a response and the number of details. However, without going into a lexical analysis, are there some easier and more obvious cues?
Two Channels of Communication as Sources of Lie Detection
According to University of Ghent’s Bram De Keersmaecker and colleagues (2024), theories about detection deception fall into two camps: non-cue and cue. As the term implies, non-cue theories say there are no cues that will guide you to the deceiver. Cue theories propose, in contrast, that the “underlying psychological processes of lying are fundamentally different from those involved in truth-telling” (p. 1). In other words, it’s hard for a liar to lie. It takes more cognitive effort to generate false facts that will hang together than to tell the truth.
Emotions also take away energy, from fear getting caught to feeling guilty later on. How did you feel the last time you told a little fib? Did you worry afterwards that you misled the person who thought you were being honest? This emotional pressure can leak out into the verbal and nonverbal communication channels, making the lie easier to detect.
The Belgian authors, falling into the “cue” camp, propose further, that “despite their previous underwhelming results," the two most reliable cues are speech disfluency and eye contact. Speakers are constantly monitoring what they say and how they say it, so when they lie, they really have to focus on how they get their message across. The Cognitive Demand Hypothesis (CDH) proposes that because lying is so taxing, liars will pepper their speech with more hesitation (as they think) and trip up over their own words. In contrast, the Attempted Control Hypothesis (ACH) suggests that liars are more polished when they lie because they get so much practice. Also, they know that hesitation is a dead giveaway, so they work extra hard to speak smoothly (i.e. the “smooth talker”).
When it comes to the eyes, again, previous research has provided mixed results, but the authors believe that what’s called “gaze aversion” might be worth re-examining. CDH proposes that liars avert their eyes because they feel ashamed of themselves plus they have to work so hard as they invent their falsehoods. ACH says the opposite, that liars try to look more honest by maintaining steady eye contact. Either way, the authors decided to pursue this lead.
Pitting CDH against ACH
Part of the formula for scientifically studying communication cues in lying, De Keersmaecker et al. maintain, involves distinguishing between telling the truth that you want to have appear as a lie (bluffing) vs. telling a lie that you want to appear as the truth (deception). The speaker’s intention, therefore, becomes important to consider. What do speakers intentionally use as cues when they bluff vs. deceive?
The experimental paradigm the researchers used on their 24 pairs of participants is known as the “treasure hunt.” In this task, a speaker communicates to a listener the location of a hidden object shown on a screen; a correct guess earns the listener a reward. In two of the conditions, speakers were instructed to provide information in a way that would make them believable, either by being honest or by lying. In the third condition, speakers were told that they should communicate in a way that would be deceptive by bluffing (wanting not to believed). The question was whether speakers would alter their eye contact and speech disfluencies based on condition. Additionally, the research team could compare ratings of truthfulness by the listeners of their partner’s communication.
The findings showed that intentions were enough to influence the behavior of the speakers. As the authors concluded, “The fact that the mere intention to appear truthful or deceptive was sufficient to influence speakers’ behaviour is strong evidence in favour of the ACH.". People know, in other words, that their lying eyes and smooth talking need to be controlled if they’re going to be believable.
From the standpoint of the listener, believability depended on eye contact and the repetition form of disfluency (stuttering). Both of these produced deception detection scores higher than chance (62 and 63%). These are not staggeringly high rates of detection, but they do exceed those reported in prior research. In general though, listeners were quicker to spot the truth than they were to spot a lie, suggesting that “listeners perceive speakers as being truthful by default."
How to Put These Findings to Use
Because the intention of people who lie is even more important than the truthfulness of what they’re about to say, it seems that getting to the heart of the speaker’s desires could be your first step toward spotting deception. Because the default option is to believe the person speaking to you, it will take extra effort for you to pierce through their mask of intention. If anything, the cognitive load is higher on you than it is on the speaker.
It may also be putting too fine a point on it to decide who’s bluffing and who’s lying. Either way, you’re being misled. Someone who’s bluffing will put on just as false a front as someone who’s lying. The “treasure” may or may not be where they say it is, but their desire to mislead you makes it clear that they do not have your best interest at heart.
To sum up, taking someone’s motives into account is an important part of the deception decision. Using their polished eye gaze and speech can help guide you to a clearer path to the truth.
Facebook image: Krakenimages.com/Shutterstock
References
De Keersmaecker, B., Hartsuiker, R. J., & Pistono, A. (2024). (Don’t) believe me, I’m telling the truth! Speech disfluency and eye contact as cues to veracity, intention, and truth judgement. Language, Cognition and Neuroscience, 1–15. doi: 10.1080/23273798.2024.2382728