Is it someone's legal right to not be "read" if they don't want you to know certain informaiton? Is it legally right for you to read people to discover information that they are not verbally telling you?
Your presence is an important part of who you are. How people see you will significantly affect how you communicate with them. If you can take control of your presence then you will be come a more effective communicator.
Posture is important and can convery many different meanings. Rigid, stiff, et cetera. Listen to learn of something even more important than posture when it comes to effectively communicating with others.