This is a true and often asked question by many curious observers, and the response is: No, ASL isn’t a universal language nor an international language. To get a bit of clarification here are just two reasons some observers may think it is:
(1) American Sign Language, mostly called ASL, incidentally appears to have some known worldwide features compared to other world languages that are signed.
(2) Shared linguistic universal characteristics of some world signed languages have sometimes been known as contact variety. These are known characteristics which make it possible for users of different signed languages to come together and invent strategies to communicate.
There are, of course, countless examples of contact number in signed languages, following is only 1 example. This scene occurs just outside a enormous grocery store: Sandra (not her real name) is an adult Deaf and native ASL user. As Andrew steps from the shop, he sees something unusual happening with Sandra and states, You seem lost, can I help you?
Sandra sees Andrew’s concerned look and answers with the motions like handling a car’s steering wheel while her eyes pan the parking lot. Andrew might not know any sign language but can collect from gestures that Sandra is searching for her car. In this scenario, putting together the primary elements of communication we notice three universal attributes which are; appearing lost, steering wheel, and eye-gaze. Andrew has gathered the major point of this message being conveyed, therefore allowing for communication to happen. (enter pencil and paper, yes, Andrew helps her locate her car).
No, it’s not, but it will have some universal features which make communication possible. And just as hearing people have the propensity to communicate in spoken languages along with different nations, so do deaf people in ASL, other signed languages, and along with other members of disadvantaged communities across the world.