Is sign language universal? This is a question that is often answered falsely. Unfortunately, the vast majority of people unaffiliated with the Deaf community mistakenly assume that sign language is a universal language. However, nothing could be further from the truth. There are at least two hundred identified sign languages used across the world today, and this number is steadily growing. Here in the United States, American Sign Language (ASL) is the predominant sign language used. Some other more prominent sign languages used throughout the world include Mexican Sign Language (LSM), French Sign Language (LSF), and Australian sign language, known as Auslan. While every sign language does share the communication medium of sight in the same way that all spoken languages share the medium of sound, each of these sign languages possesses its own unique hand shapes and structures. There are a limited number of hand shapes used to construct each sign language, and these hand shapes are typically unique to the sign language itself. Grammar and sentence structure varies among sign languages as well.
The assumption that sign language is a universal language is largely based on another common misconception: that sign language is a language largely based on gestures and pantomime. For now, let’s focus on ASL. In order to test the gestural nature of ASL, linguists have evaluated ASL for iconicity. Iconicity is a measure of the similarity between a sign and its meaning. Linguists would produce a sign for an individual with no knowledge of ASL, then ask the individual to guess the meaning of the sign. Overall, only 40% of ASL has been labeled as iconic in nature.
Not only are there a plethora of individual sign languages, but there is high regional variation inside each sign language itself. For example, San Diegan signers and New York signers use completely different signs for basic words like “rude” and “dog.” This regional variation presents a challenge for sign language interpreters, who must be well-versed in regional signs beyond their own. San Diego interpreters must be familiar with regional signs from across the United States.
The next time you see someone signing, remember that the particular sign language they are using is only one of over two hundred sign languages used across the world!