The human desire for communication is amazing! Those who can hear and speak instinctively pick up a language. People don’t need to know anything about grammar or verbs or adjectives. They will just start speaking. But what if you have hearing problems or speaking problems?
People will still want to communicate and this is shown in the fact that sign language developed. They are not a simple code. They are full languages onto themselves and just as complex and varied as spoken languages. If you know one sign language, it doesn’t mean you can understand every sign language. They are even related to one another like spoken languages. American Sign Language is related to French Sign Language because some French Sign Language teachers came to America to teach sign language.
A fascinating case is Nicaragua. At home, deaf children were using rudimentary signs to communicate with family. There were no specialised school for deaf children, so many deaf children just stayed at home. But when deaf schools were set up, an amazing thing started happening. All those children started signing to one another, and a whole new language started developing before people’s very eyes. The human desire for communication will break through almost any barrier! Humans feel a need to communicate with those around them, and sign languages are just one of the ways they can do that.