" If you are a parent, teacher, camp counselor, or school resource officer and you see children severely change or restrain their arm behavior around their parents or other adults, at a minimum it should arouse your interest and promote further observation. Cessation of arm movement is part of the limbic system’s freeze response. To the abused child, this adaptive behavior can mean survival. "

― Joe Navarro , What Every Body is Saying: An Ex-FBI Agent's Guide to Speed-Reading People