Read the passage carefully and choose the correct answer.

Communication in general is process of sending and receiving messages that enables humans to share knowledge, attitudes, and skills. Although we usually identify communication with speech, communication is composed of two dimensions - verbal and nonverbal. Nonverbal communication has been defined as communication without words. It includes apparent behaviors such as facial expressions, eyes, touching, tone of voice, as well as less obvious messages such as dress, posture and spatial distance between two or more people. Activity or inactivity, words or silence all have message value: they influence others and these others, in turn, respond to these communications and thus they are communicating. Commonly, nonverbal communication is learned shortly after birth and practiced and refined throughout a person's lifetime. Children first learn nonverbal expressions by watching and imitating, much as they learn verbal skills. Young children know far more than they can verbalize and are generally more adept at reading nonverbal cues than adults are because of their limited verbal skills and their recent reliance on the nonverbal to communicate. As children develop verbal skills, nonverbal channels of communication do not cease to exist although become entwined in the total communication process.

Which is not included in nonverbal communication?