Nonverbal behavior is widely recognized as conveying affective and emotional information, although it has other functions as well (such as regulating turn-taking in conversation) [...]
Non Verbal Library
When people interact with each other, they are sending verbal or nonverbal or nonverbal messages [...]
The sending and receipt of non-verbal messages are expressed and perceived in a subliminal way; some behavior are so little, like eyebrow flash or tongue-showing, that we made them without awareness [...]
Libri Di Marco Pacori