La comunicación no verbal

Albert Mehrabian (Profesor émerito de Psicologia de la Universidad de UCLA):

Albert Mehrabian (born 1939, currently Professor Emeritus of Psychology, UCLA), has become known best by his publications on the relative importance of verbal and nonverbal messages. His findings on inconsistent messages of feelings and attitudes have been quoted throughout human communication seminars worldwide, and have also become known as the 7%-38%-55% Rule.
Three elements of communication - and the "7%-38%-55% Rule"
In his studies, Mehrabian (1971) comes to two conclusions. Firstly, that there are basically three elements in any face-to-face communication:
words,
tone of voice and
body language.
and secondly, the non-verbal elements are particularly important for communicating feelings and attitude, especially when they are incongruent: if words and body language disagree, one tends to believe the body language.
It is emphatically not the case that non-verbal elements in all senses convey the bulk of the message, though this is how his conclusions are frequently quoted.
When delivering a lecture or presentation, for instance, the textual content of the lecture is delivered entirely verbally, but non-verbal cues are very important in conveying the speakers attitude towards their words, notably their belief or conviction.