Intentional communication... Week 3 Post 3

The chapter brought up the topic of whether communication is intentional.  I found this to be very interesting because the chapter brings up definition 5 which says " In the main, communication has as its central interest those behavioral situations in which a source transmits a message to a receiver(s) with conscious intent to affect the latter's behaviors." (pg 20) I do see the point of view that the author is coming from but on the other hand I feel as though non-verbal communication is just that verbal.  A lot of times when we do non-verbal communication it is unintentional so if that is the case then wouldn't it still be considered communication?  When people say something and an expression comes over your face with surprise or happiness, I feel that these are ways of communicating even though they are done unintentionally.