The carotid artery, the main blood vessel that courses through the neck, can display a heavy and escalated heart rate. As anxiety increases, so does blood pressure and heart rate, and often this can manifest in the neck through careful observation.
Other indications of elevated blood pressure can be found in the temples. The discerning observer will look beyond upper manifestations to find a pulse rhythm in the dangling foot of a leg crossed over the other at the knee, a good point to get a pulse baseline without being intrusive.
Escalated respiratory rates can result in hypoventilation, not being able to blow off accumulated carbon dioxide. This may result in pursed lip breathing, heavy sighing, yawning.
Face touching, scratching, behind the ear and the back of neck can indicate an adrenal dump, escalation in anxiety resulting in a flight or fight response. A side effect of this is itching about the face and neck causing the target to unwittingly scratch as an adaptor.
More prevelant in women than men is the rupturing of tiny capillaries, starting in the skin of the chest and working its way up to and through the neck, the result of a pounding heart.
Psychological Manifestations
When the mind is in dissonance, the body can make this manifest through various tells:
Diminishing - Gesturing becomes smaller, limited range of expression with hands and arms.
Detachment - Emotional responses are delayed, separated from their verbal expression.
Delight - Pleasure tells expressed after disclosure of trauma.
Disconnection - Expression in the eyes doesn't match expression in the mouth.
Direction - The feet tell where the body wants to go.
Eye Behavior
Blinking
Blink rates can indicate escalated anxiety or controlled contempt and a range of emotions in between. Normal blink rates range from two to ten times a minute depending on relative humidity and eye moisture. Blink rates decrease when the eye is engaged in reading or watching a screen, down to 3 to 4 times a minute.
A blink rate baseline can be derived by counting blinks per minute at resting or unescalated levels. More accurate blink rates are determined over a period of time, averaging blink rates from at least a half dozen samples.
Increased blink rates in a subject can be a result of escalated anxiety, emotion, or result from excessive eye movement. Decreased rates stem more from the alpha-male stare, the inherent decoy from being detected in a lie or escalation.
Movement
Excessive or dormant eye movement beyond an established baseline can indicate escalation.
Micro Expressions
This discovery of non-verbal human tells is from Dr. Paul Eckman. It was upon his research the show Lie to Me was based.
The concept is that while we may be feeling a base emotion, we may be simultaneously masking that emoiton. Think of the powerful influence of manners, or just being nice. Eckman asserts, though, that true emotions can punch through the patina of being nice, or stoic, or feigning interest. These flashes of truth are called micro expressions because they often happen in one thirtieth of a second.
Unlike language used to express emotions, micro expressions are universal regardless the culture. In fact, Eckman's research discovered that primates and other mammals have universal signals for emotion. For humans these emotions are identified as happiness, sadness, fear, anger, surprise disgust and contempt.
Take a look at these expressions from some of my interns:
See if you can identify them.
Chances are you went...
Happy
Sad
Surprise
Disgust
Anger
Contempt
...and you did so based on your inherent ability to identify these emotions. Most of us can. It's when these fly by you at less than half a second when this gets difficult to identify.
What can help is establishing a baseline, or a neutral, like these:
While it's tough to be completely void of emotion, like some of these students, the neutral expression is a reference for the observer to use in identifying other micro expression.
In threat assessment, of all these micro expressions, the one to be most concerned with is not anger,
...it's not disgust,
...it's this one, contempt.
Of all the micro expressions this is the only asymmetrical display. It's defining characteristic - the curled lip raised to one side, the eyes vacant in expression.
Contempt is an evacuation of conscience. When one is evaluated in contempt, their value ceases. When one is contemptuous they're above the obligation of morality, superior to their subject, perpetuated by thoughts that do not consider their subject's value. Contempt can breed vengeance, an escalated emotion common to threatening behavior.