"Body language", formally called nonverbal communication and subject of the study of Kinesics, consists of all forms of perceived or supposed communication that are not verbal; that is, do not use language. Examples are facial expression, gestures, postures, movements, voice inflections and intonations, behaviours and more. Nonverbal aspects of spoken language such as timing and articulation, as well as nonverbal aspects of written language, belong to this realm too, even though the popular term "body language" does not explicitly cover them (Nonverbal aspects of written language are a field of study in their own and will not be further discussed in this article).
Expression and interpretation of nonverbal messages are principally unconscious, which suggests the evolutionary origin of body language lies before the advent of current human awareness. It may have developed in the process of mate selection, and to establish hierarchy and maintain order in groups of animals. However, persons who professionally deal with people face-to-face or over the phone often have learnt to become aware of nonverbal communication and actively use it to manipulate their clients, students or employees. (The word "unconscious" is preferred to "subconscious" in this article.)
The contents of the nonverbal is normally of an emotional or instinctive nature and apparently helps the involved parties to know what behaviour is expected from or appropriate for them in the current social context. The nonverbal component of art, music, literature, theatre and rhetoric though is often more of an intellectual or intuitive nature.
Psychologists and anthropologists have observed that body language constitutes the majority of human communication, and estimates vary between 60 and 93 percent. Also, interpreted nonverbality appears to be dominant over language; If one receives a verbal and nonverbal message at the same time, one involuntarily believes the nonverbal even when it contradicts the verbal one.
Use and interpretation of body language vary across cultures; Perhaps apart from a simple smile, each and every nonverbal expression is taken differently by different peoples. And there is variation across personality types; Nonverbal communication is greatly reduced, absent, or deviant in persons with high introversion, autistic or Aspergoid features, or some forms of schizophrenia. In short, it is not a clearly written-out message but a drop of ink wherewith the interpreter writes his own. A walking Rorschach test onto which each projects his own shadows and allows them to override any accompanying verbal message.
Obviously, body language is one of the major causes of confusion, misunderstanding, conflict and fight between humans. As apes it served a purpose. Now we have invented language, paper, pen and ink to express our thoughts. Yet what do we do most of the time? We hand them over and say: You write my message to you. Small surprise we are misunderstood.
Obviously, body language must be eliminated from modern communication and left to the apes. We must learn to use real language exclusively to express ourselves, and, the hardest part, to interpret only the verbal component of whatever is being said to us while ignoring the apparent nonverbal one.
The latter is so hard because nonverbal signals tend to go straight to the unconscious, surpassing aware interpretation. And what thus enters the unconscious acts as suggestion, which explains nonverbality's dominance over the verbal. A suggestion given to a hypnotized subject may cause the subject to ignore any later instructions contradicting it (Whether hypnosis is a true phenomenon does not matter here; Relevant is that suggestion is a true phenomenon). This also explains why those who are most inclined to go by the nonverbal component of what is being said are typically the highly suggestible, the empathic, those who easily let their mind state be determined by that of others. These are also the ones with narrow associative horizons, the ones who are procreative rather than creative. On the other hand, those who resist nonverbality or are blind to it tend to be creative rather than procreative.
Exactly how to rid ourselves of this plague is a question that requires more study. At the moment we can only speculate; Perhaps verbal education as in this article helps. Or, a more imaginative and powerful method that would reach exactly those who need it most: A universal nonverbal symbol that goes directly to the unconscious and says "Mind the verbal message only!".