Body language is communication by means of facial expressions, gestures, postures, and other wordless signals. Body language also includes grooming habits, hair and clothing styles, and such practices as tattooing and body piercing. Body language communicates unspoken information about people's identity, relationships, and thoughts, as well as moods, motivation, and attitudes. It plays an essential role in all interpersonal relationships, such as child care, politics, teaching, and public speaking. The scientific study of body language is called kinesics (see Kinesics).