The young mother leaned back and cleared her throat. Her eyes teared and her voice quivered as she explained how her baby disappeared. Her clasped hands trembled slightly and her feet pointed toward the door. Her demeanor appeared too subdued. Reluctant to call the mother a liar, the investigator asked her if she had a reason to lie. She answered, "I never lie. My mother taught me always to tell the truth." The investigator had seen and heard enough--he asked the woman to take a polygraph examination. During the postpolygraph interview, the woman confessed that she had suffocated her baby. Both her verbal and nonverbal behaviors had revealed the gruesome truth.
From heated knife blades across the tongue to electric prods, people have sought ways throughout history to test the truthfulness of others. Fortunately, researchers in criminology and psychology have identified verbal and nonverbal behaviors that detect deception in a more humane manner. Nonetheless, detecting deception remains a difficult task. In fact, multiple studies have found that lie detection, like a coin toss, represents a 50/50 proposition, even for experienced investigators.  Although detecting deception remains difficult, investigators increase the odds for success by learning a few basic nonverbal and verbal cues indicative of lying.
Lying requires the deceiver to keep facts straight, make the story believable, and withstand scrutiny. When individuals tell the truth, they often make every effort to ensure that other people understand. In contrast, liars attempt to manage others' perceptions.  Consequently, people unwittingly signal deception via nonverbal and verbal cues.  Unfortunately, no particular nonverbal or verbal cue evinces deception. 
Investigators' abilities to detect deceptive behavior depends largely on their ability to observe, catalogue, and differentiate human behavior. They must identify clusters of behavior, which cumulatively reinforce deceptive behaviors unique to the person the person interviewed.  Investigators also should learn to formulate questions to facilitate behavioral observations. The more observations investigators make, the greater the probability of detecting deception. For the most part, family members and close friends display patterns of genuine openness. For inexperienced investigators, these behavioral patterns may serve as a comparative reference for contrast with deceptive behaviors.
The Interview Setting
The ideal setting for an interview places the interviewee in a position where no obstacles, such as tables or desks, block the interviewer's full view of the subject's body. A large portion of nonverbal behaviors emanates from the lower body, not just from the hands and face. Feet that fidget or point to the door communicate discomfort.  If subjects sit behind a desk or table, officers should encourage them to relocate. Deceivers often use soda cans, computer screens, and other objects, both large and small, to form a barrier between themselves and investigators.  Objects used in this manner create distance, separation, and partial concealment--behaviors consistent with dishonesty.
Many investigators rely too heavily on eye contact. Research indicates that people, especially frequent liars, actually increase eye contact because they learned that investigators often gauge veracity by strong eye contact.  Nevertheless, eye aversion during difficult questions, as opposed to benign questions, can depict distress.
Eyes do not just see, they communicate when the brain conducts internal dialog, recalls past events, crafts answers, or processes information. Eyes also serve as a blocking mechanism, much the same way as folded hands across the chest or turning away in disagreement. When people hear or see something they disagree with or do not fully support, their eyelids tend to close longer than a normal blink. This automatic response occurs so quickly that most extended eye closures go unnoticed. By cataloging a person's baseline eye responses during nonstressful conversation, investigators can compare the eye responses with those during critical questions.
Hand or finger movement to the eyes usually follows a prolonged eye closure, further blocking out auditory or visual stimuli. Additionally, individuals who struggle with an idea or concept often blink their eyes rapidly. Rapid blinking or "eyelid flutter" signals a sensitive topic.  Officers carefully should observe the speaker's eyes, which can alert to the possibility of deception.
Head and Body Movements
Head movements should comport with verbal denials or affirmations. For example, an inconsistent head movement occurs when individuals say, did not do it" while their head subtly nods affirmatively. Investigators often miss inconsistencies between the spoken word and nonverbal behavior. 
When people feel comfortable, they tend to mirror the head movements of the person with whom they converse. An unwillingness to mirror the investigator's head movements or other gestures could indicate discomfort, reluctance to cooperate, or, possibly, deceit. 
Truthful people tend to lean forward as they converse; liars tend to move away.  Therefore, if speakers lean backward when telling their version of events, the statement likely involves some deception or reluctance to provide information.
Mouth and Breathing
People who attempt to conceal information often breathe faster taking a series of short breaths followed by one long deep breath.  This irregular breathing pattern can tip investigators to speakers' increased anxiety levels. Additionally, stress often causes a dry mouth, resulting in repeated clearing of the throat, cracking of the voice, or jumping of the Adam's apple (laryngeal cartilages).  Likewise, a tense mouth with pursed lips may represent extreme distress and signify that speakers literally restrain themselves emotionally, verbally, and physically.
Hands and Arms
Confident people usually spread out in an area. Less secure people tend to occupy less space, fold their arms, and interlock their legs.  Similarly, a person whose lips, hands, or fingers tremble or who hides their hands may exhibit low confidence, although these characteristics do not guarantee deception.
A liar rarely points a finger or emphasizes with hand gestures.  Finger pointing or hand movements exude confidence--qualities liars usually lack. The finger-pointing cue usually does not apply to actors or politicians because they train themselves to appear confident during public appearances. Also, liars rarely display steepling--fingertips touching each other forming a triangle with both hands, which, symbolically, represents assurance of thought or position. 
Liars often slouch in chairs feigning comfort. Liars may even yawn repeatedly reinforcing the appearance of relaxation, even boredom. In addition, yawning during stressful situations or spreading out on a couch or chair when circumstances call for tension and discomfort portends deception. 
Liars often keep their hands motionless and draw their arms close to their bodies into a position as if "flash frozen." In many cases, speakers' knuckles turn white as they clutch the armrest.
Liars prefer concealing the truth rather than fabricating an entirely fictitious story.  With concealment, the liar only needs to avoid revealing untrue information.  In other words, the liar conveys the truth up to the event he wants to hide. At this point, the liar uses a "text bridge" to gloss over the concealed activity.  After crossing this sensitive area, the liar again relays the truth. The use of text bridges alerts the investigator to a topic that may require closer examination.
Text bridges enable the speaker to fast forward through time connecting salient events without discussing the included activities. For example, if a man says, "After I took a shower, I ate breakfast." The listener assumes that the man disrobed, turned on the water, got into the shower, washed his body with soap, rinsed the soap off his body, shampooed his hair, rinsed his hair, turned off the water, got out of the shower, and dried himself with a towel. Someone reluctant to tell the truth often uses this same technique to gloss over sensitive topics. For example, a person reports the following: "I left the house to go to work, and when I returned home, I found my wife lying in a pool of blood." The text bridge "when I returned home..." should alert investigators to missing information. Investigators should examine, in detail, the man's activities from the time he left the house until the time he returned. The interview should not proceed until the speaker adequately explains his activities. Some commonly use d text bridges include "I don't remember...," "the next thing I knew...," "later on...," "shortly thereafter...," "afterwards...," "after that...," "while...," even though...," "when...," "then...," "besides...," "consequently...," "finally...," "however...," and "before...."
Stalling tactics, such as asking the investigator to repeat the question, provides additional time for deceivers to think up an appropriate answer. Liars typically ask investigators to repeat questions without realizing that honest conversations do not require the restatement of questions.  Other stalling phrases include "It depends on what you mean by that," "Where did you hear that?" "Where's this information coming from?" "Could you be more specific?" or "How dare you ask me something like that."  The phrases "Well, it's not so simple as yes or no," or "That's an excellent question," also provides speakers with additional time.
Research shows that guilty people often avoid using contractions.  Instead of saying, "It wasn't me," liars will say, "It was not me, to ensure the listener clearly hears the denial. Additionally, liars euphemize to avoid reality.  Likewise, responses such as, "I would never do that," "Lying is below me," I have never lied," or "I would never lie," or, "I would never do such a thing" should alert investigators to the possibility of deception. Other statements such as: "to be perfectly frank...," "to be honest...," "to be perfectly truthful...," or "I was always taught to tell the truth," often intend to deceive.
Making a positive statement negative provides the liar with the quickest, easiest answer to an accusation. For example, the investigator asks, "Did you steal the money?" The person responds, "No, I did not steal the money." The guilty person responds quickly to avoid the impression of a delayed answer.  A variation of this technique occurs when a person answers "yes" or "no" immediately, but the explanation comes more slowly because the liar needs time to construct an answer. 
Deceptive people rarely include negative details in their explanation of events, unless, of course, the story concerns delayed or canceled plans.  Truthful people reference the negative as well as the positive events in their stories.
Silence makes many people uncomfortable.  Liars usually continue speaking until they confirm that the listener accepts their version as the truth. If investigators stare patiently in silence unconvinced, the deceitful person likely will reveal information, not in response to questions but rather to fill the silence.
Investigators who learn and routinely employ basic nonverbal and verbal skills during interviews gain valuable insights into the veracity of the person interviewed; however, if unpracticed, these skills deteriorate over time. The more skilled behavioral observations investigators make, the more accurately they can form an opinion as to the truthfulness of the speaker. However, no matter how skilled the investigator, the fact remains that no particular nonverbal or verbal behavior, in and of itself, indicates deception.
Investigators cannot prevent people from lying but, at least, they can observe and catalog behaviors that indicate, but do not necessarily conclude, deception. The only certain method of discerning the truth relies on the corroboration of the known facts independent of the information provided by the person interviewed. 
(1.) Paul Eckman, Telling Lies: Clues to Deceit in the Marketplace, Politics, and Marriage (New York: W. W. Horton and Co., 1955), 287 citing M. O. Sullivan, P. Eckman, and W. V. Friesen, Journal of Nonverbal Behavior 12 (1988): 203-15.
(2.) David J. Lieberman, Never Be Lied to Again (New York: St. Martin Press, 1988), 41.
(3.) Sigmund Freud, Fragments of an Analysis of a Case of Hysteria-Collected Papers V. 3 (New York: Basic Books, 1905), 94.
(4.) Supra note 1, 80.
(5.) Supra note 1, 80.
(6.) David Lewis, The Secret Language of Success: Using Body Language to Get What You Want (New York: Galhad Books, 1955), 221.
(7.) Ibid., 169
(8.) R. E. Exline, J. Thibaut, C. B. Hickey, and P. Gumpert, Visual Interaction in Relation to Machiavellianism and an Unethical Act, citing R. Christie and F. L. Geis, eds., Studies in Machiavellianism, (New York, NY: Academic Press, 1970), 53-75.
(9.) David G. Givens, The Nonverbal Dictionary of Gestures, Signs, and Body Language Cues (Spokane, WA, Center for Nonverbal Studies, 2000), available from http://members.aol.com/nonverbal2; accessed November 17, 2000.
(10.) Supra note 1, 289.
(11.) Gordon R. Wainwright, Teach Yourself Body Language (London: Hodder Headline, 1985), 37.
(12.) Supra note 2, 23.
(13.) Supra note 2, 54.
(14.) Supra note 2, 54 and note 9.
(15.) Supra note 2, 14.
(16.) Supra note 2, 24.
(17.) Supra note 2, 198.
(18.) Bella M. DePaulo, "Nonverbal Behavior and Self-preservation," Psychological Bulletin 111, no. 2 (1992): 214.
(19.) Supra note 1, 29.
(20.) Supra note 1, 20.
(21.) The term "text bridges" was coined by the authors; however, the concept of "missing information" was developed by Avinoam Sapir, The L.S.I. Advanced Workshop on Scientific Content Analysis (SCAN), (Phoenix, AZ, Laboratory for Scientific Interrogation, 1992) ii.
(22.) Supra note 2, 49.
(23.) Supra note 2, 46.
(24.) Supra note 2, 30.
(25.) Supra note 2, 28.
(26.) Supra note 2, 28.
(27.) Supra note 2, 35.
(28.) Supra note 2, 43.
(29.) Supra note 2, 31.
(30.) J. Reid Meloy, "The Psychology of Wickedness: Psychopathy and Sadism," Psychiatric Annals 27:9 (September 1997): 630-33.…