The following is a summation of body language and physical tells based on the book "What Everybody is Saying" by Joe Navarro. I spent a couple of days people-watching recently and, when you know what to look for, it becomes blindingly obvious how people are feeling about each other. General Principles:
- The 'honesty' of the body increases with the distance from the head - making the feet the most reliable of tells.
- Before trying to read someone's intent or disposition, you should first establish what that person's baseline is - what position they normally adopt. You then observe them carefully for sudden changes away from that norm.
- Basing a reading on a single tell is dubious at best, you are looking for clusters of behaviours, sequences of or repeated actions.
- Remember to consider the general context of the situation - how much stress is 'normal' - what actions are simply the result of the space which you/they are occupying..?
- Freeze, flight, fight. Stress reactions usually follow this sequence. You are looking sometimes for sudden absences of movement as well as everything else. Children for example, usually freeze, or become subdued, body-language-wise, in front of people or things they are scared of, or feel unhappy with.
Basic Types:
- Upward movements indicate positivity or happiness.
- Downward movements indicate negative reactions, disapointment.
- Outward movements, or exposing of chest and abdomen (ventral) express confidence, amiability.
- Inward, or self-restrictive movements, or covering of chest and abdomen (shielding) indicate stress.
- Leaning toward something, or leaning away (plus general proximity overall) indicates the degree of comfort felt concerning that object or person.
- Sudden stillness and shallow (quiet) breathing is a tell of fear and stress.
- Mirroring. When two people begin to mirror or copy each other's movements and postures, this means they are getting on. It also sometimes means that the instigator of the subsequently copied movements by others is the top dog, dominating the situation.
* If it changes to a larger movement, involving the shin - more of a kicking than a bouncing - this indicates stress, as does a strict vertical up-down movement of the foot.
* Careful of (a) jittery (restless) leg syndrome - which is a medical condition - And (b) twitchy legs/feet which can indicate impatience depending on the context. Changes in the nature of the movements are what you should watch for.
*Shoe play (female) usually means comfort, or that she likes whomever she's with - also watch for feet being extended toward, or pulled back from someone - this is a good indicator of how comfortable someone is with that person.*If the feet pull right back under the chair, and cross at the ankles for extended periods, then that person is vey uncomfortable, and feeling threatened. Sometime the feet will also lock themselves around the legs of the chair.
*Watch where people's feet are pointing, because they usually indicate what that person's thinking about. If, when in conversation, one or both of someone's feet point away from you, or toward an exit, it means they wish to break off that conversation, or are uncomfortable or distracted. Watch for changes, if the they re-orientate on you, you have successfully re-captured their whole attention.*If someone's feet cross at the ankle (when standing) it indicates that they are very comfortable. Crossed ankles put people off-balance slightly, and necessitates their standing on one leg - which means they have no thoughts of escape and feel totally unthreatened.
*In the opposite case, not only will someone's feet point away from you, but may start to twitch - "runners feet" - as if they are about to race away.
*If a foot rises and starts pointing at the ceiling - that person is happy. In fact any movement of the body, or part of the body, which seems to defy gravity is a sign of comfort, happiness and positivity. 
* Leg Clense: This is when someone rubs the palms of their hands over their knees and thighs. This is a pacifying gesture, self-calming, and means that person has undergone stress, or is unhappy with something that has occurred.
* Knee-Clasp and Starter's-Position. These are the same thing. If sitting, the person's legs part, their weight shifts forward and they put their hands on their knees - this means they want to leave. If standing, again their weight shifts, their balance changes and their knees flex slightly - as if they were unconsciously getting ready to spring from the starter's blocks - and they are - they want to leave.* Gait: People walking without purpose generally dawdle, and look around. People who are late, are going somewhere, or thinking intensely about what they'll do when they get there, walk faster, straighter and usually look fixedly ahead. Watch for people who suddenly change gaits, or vector toward a target.
Not all shielding behaviour is so obvious. Any movement in which the arms or hands cross the chest - a man playing with his watch, a woman touching her necklace, or covering the hollow of her throat where a necklace would be, someone claspping an object - briefcase, clipboard - to their chests - are good indicators that what they are hearing or seeing is stressing them somehow. Sometimes a person will unconsciously place objects to form a 'wall' between themselves and the person who is stressing them.
Conversely, revealing the chest, even rolling up your sleeves or undoing your top button, are indicators of comfort, as is removing items between yourself and another so you can see them better.
* Blood and Breathing. If someone's breathing alters, or they blush or become pale, it tells you a great deal. Pallor is a fear/stress response, conserving blood in the organs, taking it away from the skin. Shallow or quiet breathing is also a freeze response - hiding the noise.
A red face, or a blooming of the skin in general means comfort, and sometimes aggression/attraction. Flared nostrils and heightened levels of breathing means someone's getting ready for action. Look for context, and body stance.
Arms: More honest than the hands, look first for surface information - tattoos or their remnants, and at the extreme end of the scale - the crosshatched scars of a BP self-mutilator.
* Loose arms and outward palms: "Look I'm unarmed" - means the person is welcoming, comfortable and often is the preliminary movement of a hug.* If the shoulders also raise in the classic shrug alongside the above, it's an honest shrug - the person indicating that they honestly do not know, that they aren't hiding anything. However, if only one shoulder is raised - a half-shrug - chances are that it's dishonest, done for niceties sake at best, or that the person is concealing something.
*Arm posture: As always - upward, bouncy motions of the arms indicate positivity, happiness, and droopy, slow arms mean the person is tired or sad, especially if the shoulders are also down and/or hunched. Warding gestures (variations of a policeman's classic "halt" gesture) are an attempt to distance yourself from something distasteful or stressful. Outstretched arms - the hug invitation - are only honest if the elbows are locked and the arms at full stretch, bent elbows mean the invitationis only half-hearted/dutiful.
*Folded Arms: (covered above - shielding) if restrictive - ie. tightly held, indicates the person is holding themselves back - stressed - or perhaps self-pacifying. The same with a tightly held bag cradled in both arms/hands. Not happy signs.
*The Prison-Walk: Both hands locked behind back. Depending on context it is either a pensive walk - someone thinking intently - or a passive/aggressive "I don't like you/I don't like it here" - basically it means "Don't touch me." A withdrawal of hug-possibility. Lol.
Hands: Our hands, second only to the face, are the most expressive. We pay so much attention to them that people automatically distrust those who hide their hands when they are speaking. Lawyers specifically warn both witnesses and the accused to keep their hands visible to the jury whilst giving testimony. They are also not always to be trusted, as many people who are practiced in public speaking are trained to use hand gestures to emphasize and support their rehtoric.
*Thumbs up/down/visible/concealed: In general, thumb position is a good indicator of how confident a person is about whatever is happening. People who stick their thumbs in their pockets display less confidence than those who put their hands in, and leave their thumbs stuck out. If in conversation the thumbs stick up, then that person is confident about what they are saying, if they suddenly go down, or hide themselves, then that person is no longer confident.
*Handshakes: Typical handshakes vary between cultures in strength and duration, and even how many hands are used to shake with. Some cultures hug briefly, or kiss cheeks as well and grasp hands. Some cultures continue to hold hands as they converse. If however their is no cultural difference between you and the person you're shaking with, and you feel uncomfortable with their handshake - it's a bone-crusher, very weak, they touch the inside of your wrist, try to manoever your hand so theirs is on top, or do the politician's double-cup (if they are not politicians) then somethng is wrong, either that person is an asshole, or they think you are.*Sweaty Palms: A sweaty palm does not mean that person is lying. There's a chance they have a medical or genetic condition (5%) or simply that they are nervous, or stressed. A better indicator of lying hands are ones that seem strangely still, or if the person restrains their hands - by sticking them out of sight, under their armpits, or rigidly folding their arms.
*Steepling: Steepled fingers are a very dramatic sign of confidence - used by lawyers and politicians. If they suddenly collapse into the finger-interlocked 'praying' position, then that confidence and positivity has also collapsed. Watch thumbs also, their up/down position provides commentary while the fingers hold either position.*Rude gestures: Pointing at someone, though not obviously insulting, is always interpreted as rude, and threatening. Someone can also secretly give you the finger by pushing up their glasses with their middle finger. The UK varient is two fingers - the victory sign reversed. Many cultural varients exist. The fingers and hands may also take up a 'strangling' position, though this is often a micro gesture, only held for an instant.
*Trembling/quivering hands. Often very obvious if someones holding a cigarette or pencil. Trembling is symptomatic of age, alcoholism, or too much caffeine. Depending on context it also shows excitement or nervousness.
*Preening: Knocking lint off your shoulder, raking your hands through your hair another preening activeties are normal between courting/loving couples, but show nervousness if done repeatedly in everyday conversation. They are also a form of ignoral/dismissive behaviour if the person doing them is obviously otherwise confident.
*Hand-wringing/plam rubbing: Clutched hands with white knuckles demonstrate pleading, low confidence. If someone begines to rub their plams with the fingers of their other hand, it is a pacifying movement, indicating stress. Touching/rubbing the neck anywhere with the hands or fingers is also a pacifyer, displaying low confidence.*In general: Watch for micro-gestures of the hands - these are very truthful - very quick hand displays. Watch for hand extention and withdrawal - like the feet, they inicate comfort/positivity - extended = happy; withdrawn = unhappy. Watch also for absences. When someone is telling the truth, they emphasize it with their hands naturally. If someone's lying, their hands are much less emphatic, strangely stilled, as though the rational (deceptive) brain 'believes' what they are saying, the limbic 'body-brain' does not.
*Eye-Guarding. Because the eyes are vunerable we unconsciously (usually) guard them from harm - not really recognizing the difference between physical or mental harm. Squinting, lowered brows, pupils contracting, touching or blocking the eyes with fingers or hands, all mean the person has experienced a negative/stress-response to the subject at hand - be it a person, an object or something said. The reverse, positive reaction, is flashbulb eyes, widened pupils, brows raised.
*Eyelid flutter: Usually the person is internally conflicted, struggling for words. Licked lips is also another "I'm considering my options" expression. If the tongue comes out momentarily, that person thinks they've made a mistake, or given something away.
*Compressed lips/puckered lips: Much like eyes, our lips attempt to seal themselves when we are presented with something we don't like. (All of these behaviours are very infantile - "I'm not eating that", "I don't want to look at that") Thinned lips mean disagreement, pursed lips, disapproval. Disgust/contempt exaggerates the pursed lips into a sneer, and sometimes are accompanied by eye-rolling or looking pointedly away.*Nodding, Shaking, tilting. We often nod or shake our heads to emphasize what we say. Watch for people whose body language and speech are out of sync - a nod with a no etc. If someone tilts their head up, they are displaying confidence, if down, low confidence. If someone tilts their head to the side, they are comfortable with someone or a situation.
Finally: Don't expect to become expert overnight, best to find somewhere public, where you can watch a lot of people full-body, talking and interacting - and watch. When you get into the habit of listening to people with half an ear on what they say, and two eyes on what their body is telling, thn you've cracked it.
