Development of the ability to express emotion is probably related to maturation of the brain, since children of all cultures show a similar pattern. Even deaf and blind children make same facial gestures to express or display joy, sadness, disgust, and so on. However, facial expressions of fear, surprise, sadness, disgust, anger and happiness are recognized by people of all cultures. Smile most universal and easily recognized facial expression. The study of communication through body movement, posture, gestures, and facial expressions.
Body language communicates an overall emotional tone.
Overall posture can indicate one's emotional state. A mixture of two or more basic expressions. Face is capable of producing some 20,000 different expressions. Face most expressive and most frequently noticed part of body. You decide if a situation is relevant or irrelevant, positive or threatening.