[@TheUnknowable]  As I explained in my original post, sign language is impossible because of a genetic defect in that everyone has the same level of juvenile arthritis, developed from birth (just one more reason for an astute character to be a teency bit suspicious of the Progenitors as time goes on). As for the body language thing, the Progenitors preach that actions speak louder than words. (Gee, I wonder where we've all heard THAT before? ^.-)

"Actions speak louder than words" is the basis for the entire roleplay, really. Except that words do have value and that they should always be used with care (hence my signature quote).