How To Spot A Liar

We all lie. Anyone who says otherwise is a liar.


We stretch or embellish the truth to get ahead or to protect the feelings of others--every day.

There are some lies that do not matter too much, but some people take stretching the truth to an extreme. It may be tricky to distinguish between those that embellish the truth and those who outright lie, but it is important in many situations to spot a liar.

 Why Do We Lie?

A first step in spotting a liar is to understand the motivation behind the lies. There are some common reasons to lie:

  • To protect ourselves from consequences (I did not have sex with that woman!)
  • To protect others from consequences (My child could not have done that...!)
  • To enhance a story (No kidding, the fish was THIS big!)
  • To make someone feel good (No, those pants don't make you look fat.)
  • To gain something (such as a used car salesperson hawking a "lemon.")
  • To hurt others (use of gossip to climb the corporate ladder or to feel superior).

Understanding the different reasons for lying can help you spot lies if you consider the circumstances. That knowledge will allow you to look more critically at your personal interactions.

How Does a Liar Act?

The brain is not wired to lie. It takes mental effort to lie. (Source: Kircher, 1981; Vrij, Fisher, Mann, & Leal, 2000.)

In a conversation, a liar will cover up truthful responses and attempt to maintain credibility. Most liars monitor the other person's reaction to their story. Other liars will self-monitor their own actions or words to maintain the appearance of innocence.

All of this activity takes additional mental effort and that mental effort has been shown scientifically to manifest in physiological changes. The polygraph and the latest advancement in lie detection, the ocular-motor deception test, are based on this fact. (Sources: American Psychological Association, 08/2004 and Journal of Experimental Psychology: Applied, 09/2012)

Typical physiological changes include:

  • Increase in heart rate, blood pressure, rate of respiration
  • Skin temperature changes - face may flush, hands get cold
  • Pupils dilate
  • Increase in cognitive load
  • Possible voice fluctuation or change in speech response rate

Paying attention to these physical changes may help you detect a liar in a conversation, but all of them, except pupil changes, may be difficult to detect if the other person is comfortable about lying. However, pupil dilation changes are slight, but involuntary. If a person telling more serious lies, most of these physiological changes can become more obvious. Physical reactions to lying typically increase according to the seriousness of the lie. The more serious the lie, the more serious the symptom.
 
Can You Spot a Liar?

While paying attention to another persons' body language might clue you in to a potential lie, it is by no means a guarantee that they are lying. Contrary to what you might expect, an experienced liar often comes across as helpful and truthful and puts more effort into impressing those with whom they speak.

Behaviors such as averting the eyes, touching the body or face, or covering the eyes or mouth while speaking have not been found to be reliable indicators of deception, especially with someone aware of these tells. Indeed, sometimes what is initially seen as a sign of deception may really be a symptom of nervousness, anxiety, or stress stemming from the conversation.
 
Tips to Spot a Liar
 
Because it can be difficult to spot a lie solely based on a person's physiological changes, it is important to look for other telltale signs.

Lag in response time
Liars may have a mental lag after being questioned in order to concoct the cover-up. Consequently, they can be slower to respond initially to questions or comments.
 
Nervous?
A nervous liar may tend to talk too fast, give too much information, show unusual gestures, or avoid eye contact. If the reason for lying doesn't introduce as much guilt, the liar is less likely to get nervous.
 
Compared to What...?
Ask about other things with more serious consequences and compare them to the topic of discussion. Issues with more serious consequences invoke stronger reactions. If you suspect someone may not be telling the truth, try upping the stakes in the conversation and then pay attention to their physical reaction.
 
Complicate it
Because lying takes so much mental focus, liars tend to try to stick to simple stories, and avoid complexity that might trip them up. So if you suspect a liar, ask more complex questions. Complexity increases the need for a liar to think on their feet to create the cover-up and may make it easier to spot the lie.
 
Put It In Reverse
Along similar lines, you can also ask for a story to be told in reverse order. A liar will tend to rehearse his/her story from start to finish and not from finish to start. If the story is a lie, the order of the story's events will likely become jumbled or confusing.

Prior or Later Events
If you suspect a story is made up but want further evidence, you can also ask about events they either led up to or followed the story. Because lies often have a specific beginning and end, when asked about events that either led up to or followed the story liars may have trouble coming up with an answer.

Evidence
If you indicate that you have various types of evidence that prove the story to be false, such as a photo or witness, a liar will sometimes confess based on their belief that they have been caught.
  
The Honest Person Problem

While there are many signs that a person is lying, the fact that a person is displaying some of these signs is not necessarily a guarantee that they are. Truthful individuals, under stress, often demonstrate many of the stereotypical behaviors erroneously believed to be associated with deception: speech errors, fidgeting, and gaze aversion. So even if someone seems to be displaying signs of deception, it is important to look a little deeper before assuming that they are.
 
Do These Tips Really Work?
 
While the tips given here may help you discern some lies from truth, it is in no way a failsafe method to detect deception in others. In fact, studies show that most people can spot a liar 54% of the time. You might as well flip a coin. (Source: Bond & DePaulo 2006)

It may be better, under some circumstances, to seek professional assistance.

Note: This article and the opinions expressed here are from Russ Warner, VP of Marketing at Converus, makers of EyeDetect, an innovative, new lie detection solution.

World's Biggest Liar photo by Alan Cleaver / CC BY-SA 2.0
Polygraph machine photo by Gabriel Rodríguez / CC BY-SA 2.0
Pinocchio photo courtesy of Wikipedia.