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Can you tell when someone is being dishonest with you? What are the subtle cues you use to spot a liar? Is it the liar’s fidgeting hands, their darting eyes, a tremble in their voice, or their strained smile? What cues do you use to detect liars, and are those cues accurate?
People Lie
Lying is pervasive in our culture. When researchers have examined the rates at which people lie, they have found that people lie in a sizable proportion of their social interactions with others. However, there is a high degree of variability in lying, with most people telling few lies, and a smaller subset of people telling quite a large number of lies.
People Are Poor Lie Detectors
If lying is commonplace, it seems that people would develop some practice at ferreting out dishonesty. So are we proficient lie detectors? While most people believe that they are fairly capable lie detectors, it turns out that people are abysmal at discerning truth from lies.
A number of very well-constructed studies have explored the accuracy rates of people attempting to identify liars, and these studies have consistently found that most people cannot distinguish between honest and dishonest people. In fact, most people perform only slightly better than chance in these sorts of experiments. In a very comprehensive analysis on this topic, Bond and DePaulo (2006) found that in the 206 studies they reviewed, the typical accuracy levels were 54 percent, where 50 percent accuracy would be expected by chance alone. This means that most people perform only slightly better than random guessing when trying to detect liars. Taken together, these findings throw cold water on any illusions we might have about our ability to use behavioral or verbal cues to root out the liars among us.
How Do Liars Actually Behave?
A good starting point in lie detection is to examine how liars actually behave. Researchers have discovered that people tend to exhibit a decrease in some of their body movements such as fidgeting with their fingers, hands, and arms, shuffling their feet, or squirming in their chairs when they tell lies. In studies that have examined eye contact, the results suggest that when people lie, they make more eye contact than they do when telling the truth. Other researchers found that people blink their eyes less often when telling a lie. Liars also tend to smile less frequently. These studies seem to suggest a reduction in many movements when people lie.
Other studies have examined how speech changes when people lie. These studies found that when people lie, the pitch of their voices tends to increase. Additionally, liars take slightly longer to respond to questions. Other studies have found that the actual content of speech is different when people lie. For instance, liars tend to provide fewer details, are less likely to describe their own feelings, and are less likely to provide logically consistent stories.
Other researchers also found that liars’ responses tend to contain fewer words overall. When people lie, they also tend to use more fillers in their responses such as “uh” and “um.” Thus, it appears that despite liars’ strategic attempts to conceal their deception and appear more honest, there may be some subtle behavioral and verbal cues that they let slip.
Looking for Lies in All the Wrong Places
If the research suggests that people tend to behave differently when they are lying, why are the rates of accurate detection so pitiful? One possibility is that people are simply looking for the wrong cues when trying to detect liars.
A number of studies have examined what behavioral features people pay attention to when they are trying to discover if someone is lying. Most of this research has found that people seem to have little insight into the actual behavioral indicators of lying, and so they tend to look for the wrong signs of deception. In a study I conducted with my colleagues, we found that most people believe that liars tend to increase their fidgeting, moving their arms and legs unnecessarily. As mentioned previously, the reality is that liars actually fidget less. Additionally, people incorrectly believed that liars tend to avoid making eye contact or tend to avert their gaze.
Even supposed experts in detecting deception such as police officers, prosecutors, and judges hold many of these mistaken beliefs about what the behavior of a liar looks like. These results seem to suggest that even professional experience with people who regularly lie does not leave someone with a sound understanding of what behaviors to look for when attempting to spot liars.
In a large international study, researchers found that the pattern of incorrect beliefs about the behavior of liars is widespread and pervasive across cultures. In that study, the researchers examined beliefs about liars in 75 different countries. They found that the majority of people in the study held false beliefs, such as the belief that liars avoid eye contact. It seems that part of the reason that most people are inept lie detectors is that they are mistaken about how liars behave.
Training
If people are particularly poor lie detectors, and if people hold mistaken beliefs about what liars look like, perhaps some training is in order. Wouldn’t it be great to simply be trained to be a better lie detector?
If one searches the internet, they will find plenty of consultants offering to train people to become effective lie detectors (for a fee, of course). While there is variability in the effectiveness of these training programs, several researchers have conducted reviews of dozens of these training programs to assess how effective they actually are. They concluded that these programs do seem to work in shaping people into better lie detectors, mainly by dispelling incorrect myths about the behavior of liars. However, the magnitude of this improvement is relatively small. No training program exists that can turn a lousy lie detector (as most of us are) into a walking polygraph machine. It seems that being a great lie detector is not something that can be easily taught. Why?
It turns out that when most people lie, any changes in their behavior are very subtle, and perhaps undetectable to most. These small cues that people emit when they lie may be too fleeting or unreliable for us to use effectively. Furthermore. not everyone's behavior changes in exactly the same way when they lie. There is no consistent Pinocchio's nose.
We can also be sure that most of the widely held folk wisdom about the behavior of liars is wrong, so we need to educate ourselves if we are to have any hope of detecting accurate cues of deception. However, we should also acknowledge that even when we are provided with correct information about liars, it will only lead to very modest improvements in our ability to spot a liar.
