Lying is, in a pure physiological sense, an unnatural act." -Lewis Thomas
So why do we lie? Sometimes, it's done to embellish the story about the fish that got away. Sometimes it's intended to shelter someone who would be hurt by the truth (i.e., "Yes, Virginia, there is a Santa Claus.")
Other times, we lie to protect loved ones from danger or, for more selfish reasons, to prevent our own embarrassment. (i.e., "No officer, I wasn't speeding. Why did you pull me over?")
But, lying is also used to get ahead or to maliciously hurt others. For this reason, much time and attention has been dedicated for decades to improve lie detection. Most of the solutions or techniques focus on our physiology.
A majority of human communication is nonverbal and is conveyed by body language, facial expressions, voice and eye behavior. When under the duress of lying, some postulate that physical indicators change.
From this list of physical communication methods, the eyes are likely the most powerful source of non-verbal communication. In the 1983 film Scarface, Al Pacino's character infamously declares, "The eyes, Chico. They never lie."
We maintain eye contact when interested, or to show respect, or when feeling confident. We may break eye contact when uncomfortable or frightened. Sometimes averting the eyes is due to embarrassment or shame. And others simply have a high level of social anxiety or a low level of esteem. It seems, therefore, that you cannot really use eye contact to predict deceit.
Those who are uncomfortable or embarrassed might also touch their face or body or cover their eyes. However, those behaviors can be mimicked.
Adults tend to intentionally establish eye contact during conversations. A seasoned liar knows this and will consciously maintain eye contact to avoid detection. If fact, a pathological liar might appear calm, collected and even outgoing and comfortable.
Many associate gaze aversion with negative emotions or actions, including deceit. And as a result, some believe that it's possible to predict with some accuracy when a person is lying.
Contrary to these opinions, however, intuition is not the best source of deception detection in most cases. In fact, some studies show that people can instinctively detect deceit with approximately 54 percent accuracy. (Source: Bond & DePaulo, 2006.) That outcome is just about as reliable as a coin toss.
Oh, by the way, there is one exception to the intuition rule: mom knows when you're lying.
Cognitive overload theory suggests that if a person becomes overwhelmed with thinking or feeling, their blink rate may increase. (Source: "Quarterly Journal of Experimental Psychology, 1995.) Some believe blink rate is a good indicator of deception.
This theory also suggests that lying increases cognitive load due to the energy and thought required to fabricate an elaborate story. When creating a lie, most will think deliberately to remember events and details disclosed to each person involved.
This last theory has been applied to looking to the eyes as an indicator of increased cognitive load when creating and developing a lie. A study published in 2012 indicates that there are subtle changes in pupil dilation, gaze fixation, and other eye behaviors when lying is on your mind. And, it can be measured. (Source: Cooke, Hacker, Webb, 2012
So it's really true... "The eyes are the window of the soul." -English Proverb
Note: This article and the opinions expressed here are from Russ Warner, VP of Marketing at Converus, makers of EyeDetect.