In humans, posture can provide a significant amount of important information through nonverbal communication. Psychological studies have also demonstrated the effects of body posture on emotions. This research can be traced back to Charles Darwin's studies of emotion and movement in humans and animals.[1] Currently, many studies have shown that certain patterns of body movements are indicative of specific emotions.[2][3] Researchers studied sign language and found that even non-sign language users can determine emotions from only hand movements.[4] Another example is the fact that anger is characterized by forward whole body movement.[5] The theories that guide research in this field are the self-validation or perception theory and the embodied emotion theory.[5][6][7]