Kinesics is the interpretation of body motion communication such as facial expressions and gestures — that is, nonverbal behavior related to movement of any part of the body or the body as a whole. The equivalent popular culture term is body language, a term Ray Birdwhistell—considered the founder of this area of study—never used, and did not consider appropriate (on the grounds that what can be conveyed with the body does not meet the linguist's definition of language). Even so, many people use this term.