Here is an experiment to try next time you meet with your friends: if you are standing or sitting with your arms open, fold them and vice versa; most likely they will match the subtle gestures you are making. This happens not only in the gestures you are making but down to the tone of voice, eye blinking, walking pace and posture in what body language experts call ‘mirroring.’
Rapports can quickly be built by mirroring the people you meet. According to Allan Pease, a body language writer, mirroring is becoming a well-known concept, so do not try to be too obvious. Mirroring helps the other party feel more confident and often will improve your first impression.