We have shown that nonverbal behavior is crucial to detecting deception, but it seems that our previous discussions have been a little insufficient.

Certainly this has been a major discussion in this blog, but we have focused only on individual behaviors, like eye contact or gestures, in order to explain how important nonverbal behavior is. However, as new research by Dr. David Matsumoto and Dr. Hyisung Hwang demonstrates, clusters of multiple behaviors may be even more important.

In their forthcoming study, Drs. Matsumoto and Hwang build on previous research suggesting that focusing on a given individual nonverbal behavior is enough. They point out that lying depends on the maintenance of emotional states which help us continue our deception. This generally requires that we internalize additional emotions, corresponding to the increased cognitive work that lying requires.

While any individual nonverbal behavior may fade far too quickly to notice, a series of nonverbal behaviors born out of these additional emotions can last much longer, making lie detection easier. The goal of this study was to attempt to isolate deceptive behaviors and to see if certain patterns of nonverbal behavior tended to correspond with deception.

They hypothesized that patterns of nonverbal behaviors would reliably indicate deception and also that more open-ended interrogations would produce a greater amount of indicative nonverbal behaviors.

In order to answer these questions, they recruited a sample of students from various ethnic backgrounds and, after some initial assessments, divided them randomly into two groups. The first group was told they would be gifted a $100 check, while the second was told they could look at but not take the same $100.

The participants were eventually given the opportunity to steal the check, after which they were told that they had been “randomly” selected for an interview. Interestingly, each of them had been previously instructed to make a point of proving their honesty, regardless of their guilt. This is where the article’s data collection truly began.

The researchers employed interrogation tactics modeled after actual law enforcement techniques and utilized of a variety of open and closed ended questions, in order to test the second hypothesis. During this process, they tracked facial expressions and other nonverbal behavior like head movements and gestures.

Overall, the experiment demonstrated broad support for both hypotheses. They found that when participants lied, they produced a lower pitch in the voice and engaged in fewer head nods, which Drs. Matsumoto and Hwang suggest may be due to greater levels of emotion on the part of the deceiver.

These findings may set a new direction for research into deception detection and nonverbal behavior. Rather than just focusing on a specific feature, it is important to understand how larger underling emotional states can create persistent changes in behavior.

Naturally, this might be a bit much for any of us to keep in our head, so it may help you out to get some professional advice on properly detecting deception!

How crucial are nonverbal clues to detecting deception?

A recent 2017 study argues that reading nonverbal behavior is a crucial component to discovering mistruth and understanding if another person is lying. In this research, Dr. Eric Novotny and a team of scholars respond to previous research that underplays the role of nonverbal clues in everyday deception detection.

Their work built on a 2002 survey which asked participants how they tend to discover a lie. This survey found that most participants discovered lies through verbal cues or hard evidence, rather than noting tone, eye contact, or other nonverbal cues.

Based on that survey, Dr. Novotny hypothesized that there was a difference between discovering and suspecting a lie and that nonverbal behavior was critical to understanding deception detection. This distinction, he argued, was well-grounded in psychological research, because initial suspicion is a key part of changing one’s perception to the point that they would check a lie in the first place.

This initial framework led to a pair of studies. The first was a close replication of the 2002 survey. However, instead of only asking participants about what clues led them to discovering lies, they asked what clues led to the original suspicion of a lie. This adjusted survey was contrasted with a control group which simply asked the same 2002 questions.

Unsurprisingly, those asked the original questions reported non-behavioral factors, such as confessions or hard evidence as leading to their discovery, just as the previous research found. However, participants confirmed that behavioral evidence was used most frequently in terms of developing a suspicion, just as was hypothesized.

Dr. Novotny notes how extraordinarily different the results were with just a simple change in the questions asked. This raised the possibility that linguistic changes were more responsible for the differing results than anything else, so he conducted a second study to account for this.

This next survey worked with identical hypotheses but featured a variety of survey questions. The procedure was almost the same but divided the questions into four slight variants. Still, the same results were replicated despite minor differences in survey wording.

Because they also affirmed the 2002 study’s findings, Dr. Novotny and his fellow researchers concluded that discovering a lie is quite different from beginning to suspect one. This has critical implications on the field of deception detection. Instead of simply focusing on hard evidence, it is important to pick up on subtle nonverbal cues in order to begin to learn when we are lied to.

While we all have some ability to do this, it is also something that you can improve on, like all efforts to read people. That is exactly why Humintell offers both “Evaluating Truthfulness” and “Tactical Interviewing” training packages.

How effective are verbal cues in exposing our emotions and character?

Throughout this blog, we have dwelled extensively on deception detection but have also focused almost exclusively on nonverbal cues. However, a new study in the journal of Evolutionary Psychology, subtle verbal cues can reveal a wealth of detail about a stranger, even including past infidelity!

In an effort to see how revealing our voices were, Dr. Susan Hughes of Albright College procured a series of audio clips of different people simply counting from one to ten. Half of the speakers had elsewhere admitted to having cheated on a romantic partner in the past, while half had not.

Then, Dr. Hughes asked a series of participants to listen to various audio clips, asking them to extrapolate what they could from just the sound of the voices. These participants were given no outside details or context besides the mundane numerical recitation.

Amazingly, when asked to rank the speakers’ likelihood to cheat, the participants’ rankings matched closely with whether the speaker had a history of infidelity!

These results do have some precedent. Past research has found that verbal cues can reveal a great deal of accurate information, including the speaker’s sex, age, race, height, weight, and even social status. Perhaps most relevantly, previous studies found links between one’s voice and the emotional states beyond deception and past sexual activity.

However, despite the groundbreaking nature of Dr. Hughes’ research, there are still many unanswered questions. For example, she declined to offer a comprehensive explanation for how this is possible!

Dr. Hughes attempted to test whether the pitch of the voice had any effect on participant evaluations. She adjusted the pitch in many of the audio clips, so that the same voice was presented with a higher or lower pitch. This had very little effect, except that men tended to associate infidelity with low pitches in female voices.

This was surprising, as previous research found that pitch does impact listener judgments. Still, while pitch has some role, it “does not represent the entire picture,” as the authors wrote. Instead, “other vocal cues such as clarity of articulation may have also contributed to perceptions of infidelity.”

Perhaps this study asks more questions than it answers, but it brings the verbal aspect of deception detection into a new light.

While we wait for more information, it might be helpful to work on strengthening your ability to detect lies face to face. Similarly, you can read some previous blogs about using microexpressions to tell when you are being lied to here and here!