In humans, posture can provide a big amount of important information through nonverbal communication. Psychological studies have also demonstrated the consequences of body posture on emotions. This research can be traced back to Charles Darwin's studies of emotion and movement in humans and animals. Currently, many studies have shown that certain patterns of body movements are indicative of specific emotions. Researchers studied signing and located that even non-sign language users can determine emotions from only hand movements. Another example is that the incontrovertible fact that anger is characterized by forwarding whole-body movement. The theories that guide research during this field are the self-validation or perception theory and therefore the embodied emotion theory. An example of this is often an experiment where participants had to think then write positive qualities of themselves during a confident or doubtful posture. Participants then had to self-evaluate on how good employment candidate, interviewee, performer, and the way satisfied they might be as an employee.