In contacts between people is body language and non-verbal communication more important than the word itself. The theory of Albert Mehrabian says that the meaning of a message is transmitted for 7% by words, 38% through tone of voice and 55% by body language. So 9/10th of communication is non - verbal.

The voice itself says more than words. Even on the phone you can hear if someone is sad, uncertain, intrusive etc.. The volume can go from whisper to scream. A high-pitched voice or a low bass voice can vibrate or stutter. Intonation and accents provide texture and nuance. Monotonous boring, quickly rattling, dialect, accent, vocabulary, sentence structure, unconsciously we keep it all in mind, and we form a picture of the message. And the messenger.
I spent several months as the only Dutch working in a foreign language team. I mastered the language fluently enough to express myself and to understand the others. To be sure that I understood correctly, I have repeated many things and asked feedback. Thus seemed very clear agreements , plans... Until after a few months I realized that I did not (always) knew and understood what was not said. The concealed things, between the lines, I missed several times. Unlike in my native language.

Today we get and give a lot of information through 'phones' and displays. Screens are also filters behind which we hang up, play a role and get to see a picture. It remains important in real life to recognize those 93% signals and body language.

For use in specific situations such as applying for jobs, dating, greetings (shaking hands, kissing), flirt, meet and manage exist fifty books, courses and websites about body language. Also (ladies) magazines do a lot with it. Not assume that this is an exact science. A gesture is insufficient to draw conclusions. It is always combinations of signals and changes within a certain context. You should also take into account many cultures and customs.
The overall idea is: what happens inside, you see at the outside.

Our mouth uses 44 muscles to express how we feel. Without the rest of our face. Usually, our gestures are barely one tenth of a second visible.
Therefore gamblers try a poker face without holding any expression, or even displaying erroneous signals. While they do try to read poker faces of teammates.
Body language we speak unconsciously, so it rarely lies.
Psychic -like mystics are often masters in reading it, politicians often trained actors to use it.

Especially with emotions, body language is telling more than words: gestures, facial expressions, posture, eye contact, tone of voice. The basic emotions and spontaneous expression of it as anger, joy, sadness, fear, disgust and surprise are the same in every culture.

It makes a difference whether you speak individually with someone sitting at a conference table, or speak to an audience. With people you know well you speak differently than with strangers you meet for the first time.
Our hands or voice, touch, the way of breathing, the way of looking, alternating eye contact, facial expressions and gestures are significant. Most postures and facial expressions you do not have to study theoretical, we recognize them spontaneously from your own social experiences.

Distance and personal space
The distance we keep towards others says a lot about the relationship we (want) with them. The closer the relationship, the more we are closer to the other treaties. Remote controls: to end the call, we increase the distance. With a smaller distance can be more intimate. A variation of aloof about business, familiar to intimate. Taking into account individual and cultural differences, Hall divided interpersonal space into four different zones.

The intimate zone (0-45 cm) is to arm length. Whisper is intelligible. You can smell each other and feel each other's body heat. When forced into situations like a crowded tram or elevator we find it unpleasant.
In the personal zone (45-120 cm), you can shake hands and carry a normal conversation.
In the social area (120-360 cm) you can move freely between people who you know fairly. You greet remotely, e.g. with a head nod. Everyone adheres to a comfortable minimum distance of one meter.
The public zone (360-750 cm or more) is the anonymous zone. You can walk past someone without greeting.

The first impression of a person is formed during the first 4 seconds. But the second or third to especially the last impression acknowledges the image and trust in the other. And thus are equally important.

Head
Stand straight with your shoulders back, your head up and your chin slightly ahead if you want to exude authority. Who feels good magnifies himself. Who feels insecure cowers and takes small steps. Who stares at the ground seems nervous and even unreliable.

Continue straight watching a person can give the caller an unpleasant feeling. Focus your eyes during a conversation about 40% of the time to something else.
Leaning in the direction of the speaker, slightly forward gives an expression of interest. Hands to the face, in general, give the impression of a critical listener.
Adopting the same attitude as the speaker indicates compliance. This is also called mirroring.





Recognize lies

Several studies and experts point to a number of signals that (may) indicate lies.
Touching mouth, eyes or ears: like the three monkeys.
Avoid eye contact, looking away to the top right: he creates a visual representation of the telling rather than to look for a reminder (left, at least for right-handers).
Hesitate or repeat your question to stretch time and think about an appropriate response.
Changes in the way of talking. The tone suddenly goes up, the liar is restless and goes literally squeak by chest breathing. Otherwise, he has a belly breathing and is talking quietly. Or speak faster or slower. React angrily.
People are less personal in their language.
There is more expression (theater) and physical distance.
The story does not fit the body. (Forced laugh, do not laugh mouth, eyes.)
Many liars telling little details that are difficult to remember. Selling liars just telling much details.
And there are too extensive details called to justify the story and make it true.

Two micro- movements of raising the nose (like when you smell something unpleasant) and pull down the corners of the mouth betraye deception.

A method for unmasking is to tell a story in reverse: then is a logical statement of facts a lot harder to when it’s a lie.

In most research on lie detection people score around the chance level (50%), and experts do not do better.



Aggression

Fear can be as good as anger the reason for aggression.
In preparation for aggression, you can usually find irritability and agitation. The person is restless, agitated (pacing) and talks fast and loud, cut into sentences. He perspires more. Vibrates possible voice, arms or legs. Clenches his fists. Crosses the arms with hunched shoulders. Looks tense: the lips compressed, and the nostrils wide open, big eyes, frowning. He breathes with deep sighs and sometimes gasped.
Against things kicking or punching are the first signs of provocation, and coming into your intimate zone. He will threaten and excite you so he does not need to start arguing himself.

Seeing and experiencing aggression evokes similar emotions in people. Fear, fight and flight are our primary reactions. Flight is okay if you can run fast and escape. Rather a live coward than a dead hero.

Make by gesturing with open hands clear that you intend no harm. Don’t look him long straight in the eye and try to stay out of his personal space and do not touch him. Listen or maybe his friends call his name, which you can use.

Try to break his pattern through showing understanding. Stay polite and respectful. Maintain eye contact. Do not argue. Use I - statements instead of you - statements. Formulate your message positive and avoid weighty words (threatening).
Keep emotions under control. Demine the situation, do not let it escalate. Keep literally an escape route open for both parties, so that they can get away without losing face.

In other cultures, both habits and body language are very different. A finger on your head can mean that you find someone smart. Or crazy. In Greece, shaking the head means yes, and no kinks. Body language is not universal, no exact math or language, and context dependent. And it's certainly not a mind reader.