 It has also been stated that babies, when hungry, search for their mother's milk by moving their heads vertically, but decline milk by turning their head from side to side.An early survey of head shake and other gestures was "The Expression of the Emotions in Man and Animals", written by Charles Darwin in 1872.Darwin wrote to missionaries in many parts of the world asking for information on local gestures, and concluded that shaking head for "no" was common to many different groups.