What Is Sign Language? Full Languages, Not Gestured English

Linguistics established this over several decades, beginning with William Stokoe's analysis in 1960, which showed that signs are not holistic pictures but are built from a small set of contrasting components in the way spoken words are built from sounds. A sign is composed of a handshape, a location on or near the body, a movement, an orientation of the palm, and non-manual elements including facial expression, head position and mouth shape. Changing one of these changes the word, exactly as changing one sound distinguishes bat from pat. The non-manual elements are not decoration but grammar: raised eyebrows mark a yes-or-no question, furrowed brows mark a question expecting information, and a headshake carries negation, which means that in these languages a substantial part of the syntax is expressed on the face.

Because signing happens in space and in three dimensions, it supports grammatical devices that a spoken language cannot easily reproduce:

• •Spatial reference, in which a signer establishes people or things at specific points in the space in front of them and then points to those locations to refer back, functioning as pronouns with no ambiguity about who is meant
• •Directional verbs, where the movement of the verb itself carries who is doing what to whom, so a single sign moving from one established location to another means one person gave something to another
• •Classifiers, handshapes representing categories of object whose movement and position describe how things are arranged and how they move, allowing spatial description of great precision
• •Simultaneity, since two hands and the face can carry different information at once, which a single vocal tract cannot do
• •Fingerspelling, a manual alphabet used for names and for words borrowed from the surrounding spoken language, which is a supplement rather than the language itself

Wherever deaf people gather in numbers, a language appears, and it appears very fast. The clearest evidence comes from Nicaragua, where deaf children were largely isolated from each other until schools were opened in the late 1970s and early 1980s and several hundred were brought together for the first time. The first cohort developed a rough system of shared gestures with limited structure; the younger children who entered afterwards took that input and produced from it a language with consistent grammar, regular verb agreement and spatial reference that their older peers did not have. Linguists including Judy Kegl and Ann Senghas documented the process as it happened, and it is one of the few cases in which a language has been observed emerging from nothing. Village sign languages arise for a different reason, in communities with high hereditary deafness where everyone signs, hearing and deaf alike, as at Martha's Vineyard in Massachusetts into the twentieth century and in several villages in Bali, Ghana and Israel.

Signing has been actively suppressed for much of the last century and a half. The International Congress on Education of the Deaf, meeting in Milan in 1880 with almost no deaf delegates, passed resolutions declaring speech superior and recommending that signing be excluded from education, and the resulting oralist policy dominated deaf schooling across Europe and North America for roughly a hundred years. Children were forbidden to sign, sometimes physically punished for it, and taught to lip-read and speak, a method that works well for some and leaves many others with no fluent language at all during the years when language acquisition is easiest. Deaf teachers were dismissed in large numbers. The policy was reversed gradually from the 1970s as the linguistic evidence accumulated and as deaf communities organised, and the 1880 congress was formally repudiated by its successor body in 2010. Legal recognition has followed unevenly, with British Sign Language recognised by statute in 2022 and New Zealand Sign Language made an official language in 2006.

Two issues dominate. Cochlear implants, which can give some deaf children access to sound, have been contentious because early medical advice often discouraged signing on the theory that it would impede spoken language development, a claim the evidence does not support: studies find that early exposure to a full sign language protects against the serious cognitive and educational consequences of language deprivation and does not harm spoken outcomes. Many deaf communities regard deafness as a cultural and linguistic identity rather than a deficit to be corrected, a position that has been misunderstood as hostility to technology and is better read as insistence that a child should have at least one accessible language from the start. The second issue is access: interpreter shortages, the poor quality of automatic captioning in many settings, and the use of unqualified interpreters in medical and legal contexts remain practical problems, and the avatar systems periodically proposed as a technological fix are not yet adequate, because a system that cannot produce grammatical facial expression is not producing the language.

Sign languages are independent natural languages rather than manual codes for speech, which is why British and American signing are mutually unintelligible while American and French signing are related. Signs are built from handshape, location, movement, orientation and facial expression, with grammar carried partly on the face, and the visual medium supports spatial reference and directional verbs that speech cannot easily match. A new language was observed emerging among deaf children in Nicaragua in the 1980s, and a century of educational suppression following an 1880 congress was formally repudiated in 2010.