Do you think sign language is universal to all languages? For example something in chinese would mean something else in english. So, how would that communicate through if the person doesn't know the same language as the one they are communicating with?

This reminds me of the caution signs on the trains about not leaning on the doors, while people continue to lean on the very caution label and when in high school, we would put up a sign that the office would be closed and people still proceeded to enter and ask for the people in the offices. This shows to prove that a lot of the times either people don't read signs or they don't think the words that they read have any value or purpose.