Apparently from some CIA agents. These do sound very plausible:
Behavioral pause or delay
You ask a person a question and you initially get nothing. After a delay, he begins to respond. How long
does a delay have to be before it’s meaningful, before you would
consider it a deceptive indicator? Well, it depends.
Try this exercise on a friend: Ask her the question, “On this date
seven years ago, what were you doing that day?” The person will
invariably pause before responding, because it’s not a question that
naturally evokes an immediate response—the person has to think about
it, and likely still won’t be able to offer a meaningful response. Now
ask her, “On this date seven years ago, did you rob a gas station?” If
your friend pauses before responding, you probably need to choose your
friends more carefully. Much more likely, there will be no pause—your
friend will immediately respond, “No!” or “Of course not!” It’s a
simple exercise, but it drives home the point that the delay needs to
be considered in the context of whether it’s appropriate for the
Our brains are wired in a way that causes our verbal and nonverbal behaviors to naturally match up. So
when there’s a disconnect, we consider that a potential deceptive
indicator. "A deceptive person will often hide her mouth or eyes when
she’s being untruthful."
A common verbal/nonverbal disconnect to watch out for occurs when a
person nods affirmatively while saying, “No,” or turns his head from
side to side while saying, “Yes.” As an exercise, if you were to
perform that mismatch in response to a question, you’d find that you
really have to force yourself through the motion. Yet, a deceptive
person will potentially do it without even thinking about it.
There are a couple of caveats associated with this particular
indicator. First, this indicator is only applicable in a narrative
response, not in a one-word or short-phrase response. Consider, for
example, that a person’s head might make a sharp nodding motion when
he says “No!” That’s not a disconnect; it’s simple emphasis. Second,
it’s important to keep in mind that in some cultures, a nodding motion
doesn’t mean “yes,” and a side-to-side head motion doesn’t mean “no.”
Hiding the mouth or eyes
A deceptive person will often hide her mouth or eyes when she’s being untruthful. There is a natural tendency
to want to cover over a lie, so if a person’s hand goes in front of
her mouth while she’s responding to a question, that’s significant.
Similarly, there’s a natural inclination to shield oneself from the
reaction of those who are being lied to. If a person shields her eyes
while she’s responding to a question, what she might well be
indicating, on a subconscious level, is that she can’t bear to see the
reaction to the whopper she’s telling. This shielding may be
accomplished with a hand, or the person might even close her eyes.
We’re not referring to blinking here, but if a person closes her eyes
while responding to a question that does not require reflection to
answer, we consider that a means of hiding the eyes, and a likely
Throat-clearing or swallowing
If a person clears his throat or performs a significant swallow prior to answering the question, that’s
a potential problem. If he does it after he answers, that doesn’t
bother us. But if he does it before he answers, a couple of things
might be happening. He might be doing the nonverbal equivalent of the
verbal “I swear to God…”—dressing up the lie in its Sunday best before
presenting it to us. Or physiologically, the question might have
created a spike in anxiety, which can cause discomfort or dryness in
the mouth and throat. "A deceptive man might adjust his tie or shirt
cuffs, or maybe his glasses."
Be on the lookout for anything a person does with his face or in the head region in response to your question. This
often takes the form of biting or licking the lips, or pulling on the
lips or ears. The reason goes back to simple high school science.
You’ve asked a question, and the question creates a spike in anxiety
because a truthful response would be incriminating. That, in turn,
triggers the autonomic nervous system to go to work to dissipate the
anxiety, draining blood from the surfaces of the face, the ears, and
the extremities—which can create a sensation of cold or itchiness.
Without the person even realizing it, his hands are drawn to those
areas, or there’s a wringing or rubbing of the hands. Boom!—you’ve
spotted a deceptive indicator.
Another way that some people may dissipate anxiety is through physical activity in the form of grooming oneself
or the immediate surroundings.
When responding to a question, a deceptive man might adjust his tie or
shirt cuffs, or maybe his glasses. An untruthful woman might move a
few strands of hair behind her ear, or straighten her skirt. We’re
also concerned with sweat management. That a person might be sweating
doesn’t bother us, but if he takes out his handkerchief (or, perhaps
more likely, a hand sans kerchief) and wipes the sweat off his brow
when responding to a question, that’s significant. Tidying up the
surroundings is another form of grooming gesture. You ask a question,
and suddenly the phone isn’t turned the right way, the glass of water
is too close, or the pencil isn’t in the right place.