International Day of Sign Languages

On 19 December 2017, the United Nations General Assembly adopted resolution 72/161, fixing 23 September as the International Day of Sign Languages — a date chosen because it marks the anniversary of the founding, in 1951, of the World Federation of the Deaf, the organisation that had spent the preceding decades pressing precisely this case at the UN. The first observance followed on 23 September 2018, folded into the wider International Week of the Deaf that federations of Deaf people around the world had already been running every September since 1958. It is a day built on a single, deceptively simple argument: that sign languages are full human languages in their own right, with their own grammar and history, and that recognising them formally changes what is possible for the roughly 70 million Deaf people who use one as a first language.

The World Federation of the Deaf

The World Federation of the Deaf was established in Rome in September 1951, at the first World Congress of the Deaf, bringing together national Deaf associations that had until then operated largely in isolation from one another across different countries and, crucially, different sign languages. Its founding is generally credited to a coalition of European Deaf leaders working in the aftermath of the Second World War, during which Deaf people in Nazi-occupied Europe had been targeted under eugenic policies, including forced sterilisation programmes. The WFD grew into the leading global advocate for Deaf people’s linguistic and human rights, eventually securing consultative status with the United Nations and playing a direct role in drafting provisions of the 2006 UN Convention on the Rights of Persons with Disabilities that explicitly recognise sign languages as languages. The 2017 General Assembly resolution creating the International Day was itself the product of a WFD-led campaign, making the day less a gift from above than the culmination of a seven-decade advocacy project by Deaf people themselves.

A Century of Suppression Before Recognition

The case for the day only makes full sense against a longer and more troubling history. In 1880, an international congress of educators of the deaf met in Milan and passed a resolution declaring oral instruction — training Deaf children to lip-read and speak rather than sign — superior to sign language in schools, and calling for sign language to be banned from classrooms. The Milan Congress excluded Deaf teachers from voting, a fact Deaf historians have long treated as central rather than incidental to how the resolution passed. Its effects were severe and long-lasting: sign languages were suppressed in Deaf education across much of Europe and North America for roughly a century afterward, Deaf teachers were removed from schools in large numbers, and generations of Deaf children were punished for signing, sometimes having their hands physically restrained in the classroom. The congress’s resolution was not formally repudiated by the international body that had inherited its legacy until 2010, when the 21st International Congress on Education of the Deaf, meeting again in Vancouver, passed a resolution acknowledging the profound harm the Milan decision had caused and affirming the linguistic legitimacy of signed languages.

Sign Languages Are Not One Language

A recurring misconception the day is explicitly designed to correct is the idea that there is a single, universal sign language. There are, by most linguistic counts, well over 300 distinct sign languages in use around the world, each with its own grammar, vocabulary and history, no more mutually intelligible than spoken French and Mandarin. American Sign Language and British Sign Language, despite serving countries that share a spoken language, are almost entirely distinct from each other, a divergence traceable to their different historical roots: ASL developed substantially from French Sign Language after the American educator Thomas Hopkins Gallaudet and the Deaf French educator Laurent Clerc founded the first permanent school for the deaf in the United States in Hartford, Connecticut, in 1817, while BSL developed independently within Britain and is structurally closer to Auslan, the sign language of Australia, which descends from the same British tradition carried by nineteenth-century emigration and missionary education. Linguists have studied sign languages as full natural languages since the American linguist William Stokoe’s landmark 1960 analysis of ASL, which demonstrated that signs are built from smaller meaningful components analogous to the phonemes of spoken language, a finding that took decades to be widely accepted outside specialist linguistics but that underpins the entire modern case that sign languages deserve equal legal and educational status.

Cochlear Implants and a Continuing Debate

The day sits inside a debate that has not fully settled even within Deaf communities themselves: the relationship between medical intervention and cultural Deaf identity. The rise of cochlear implants from the 1980s onward, discussed in more detail around World Hearing Day, gave many deaf children access to spoken language they would not otherwise have had, and is regarded by much of the medical establishment as a major success. Many Deaf community advocates, however, have argued that a purely medical framing risks treating deafness solely as a deficit to be corrected rather than as the basis of a genuine linguistic and cultural minority with its own history, art forms, humour and social institutions — a position often summarised as the distinction between lowercase “deaf,” a medical condition, and capital-D “Deaf,” a cultural identity built around shared sign language. The International Day of Sign Languages is explicitly framed by the WFD around the latter position, without denying that many Deaf and hard-of-hearing individuals benefit from a mixture of signed language, spoken language, and assistive technology depending on personal and family choice.

The Convention That Gave the Day Its Legal Teeth

The 2006 UN Convention on the Rights of Persons with Disabilities, now ratified by more than 180 states, was the first binding international human rights instrument to define sign languages explicitly as languages, obliging states parties to facilitate the learning of sign language and promote the linguistic identity of the Deaf community. Article 2 of the Convention states plainly that “‘Languages’ includes spoken and signed languages,” a single clause with large practical consequences for legal recognition, education policy and the availability of sign-language interpretation in courts, hospitals and government services. Several countries have since given their national sign languages formal constitutional or statutory recognition — New Zealand recognised New Zealand Sign Language as an official language in 2006, the same year as the Convention, and Iceland formally recognised Icelandic Sign Language as a minority language with equal status to Icelandic in 2011 — though the pace and completeness of recognition still varies enormously between countries, which is precisely the gap the annual day is designed to keep pressing on.

How the Day Is Marked

Observance is coordinated internationally by the World Federation of the Deaf alongside national Deaf associations, typically as the culminating day of the week-long International Week of the Deaf held every year in the last full week of September. Activities commonly include public sign-language demonstrations and lessons, advocacy events aimed at legislators and educators, school programmes introducing hearing children to basic signs, and social media campaigns built around a chosen annual theme set by the WFD, alongside a specific colour scheme members and allies are encouraged to wear. Deaf sporting and cultural bodies, including the International Committee of Sports for the Deaf, which organises the Deaflympics, frequently tie promotional activity to the same week. Interpreting organisations and university linguistics departments often use the day to publicise research and training opportunities, since a persistent, practical barrier to full recognition in many countries remains a simple shortage of qualified, professionally trained sign-language interpreters relative to demand.

Fun Facts

Martha’s Vineyard, an island off the coast of Massachusetts, was home for over two centuries to an unusually high incidence of hereditary deafness, producing a now-extinct local sign language used fluently by hearing and deaf islanders alike well into the twentieth century — a documented historical case of an entire community growing up bilingual in a signed language, hearing and deaf islanders alike. Nicaraguan Sign Language offers linguists one of the best-documented cases of a language emerging from scratch within living memory: when Nicaragua opened its first schools for deaf children in the 1970s and 1980s, the children spontaneously developed a shared sign system from scratch that linguists have studied intensively ever since as a real-time example of language genesis. Finger-spelling alphabets differ enough between sign languages that a Deaf ASL user and a Deaf BSL user cannot simply spell words at each other to communicate, since ASL uses a one-handed alphabet while BSL uses a two-handed one. The 2021 South Korean television series and earlier international productions have occasionally cast genuinely Deaf actors using their national sign languages, a shift Deaf advocacy groups have pushed for specifically because most on-screen sign language historically was performed by hearing actors.

A Closing Reflection

The date the United Nations chose is itself a small piece of evidence for the day’s own argument: it comes straight from the calendar Deaf people had already been keeping for themselves since 1951, decades before any hearing official signed off on it. That ordering — advocacy first, recognition decades later — runs through nearly every strand of this history, from Stokoe’s linguistic proof that signs behave like language, to the 2010 repudiation of a decision passed in 1880 without a single Deaf vote cast, to New Zealand and Iceland writing their own sign languages into law. What the day asks of the hearing world each September is less a single gesture than an ongoing act of listening in a different sense than usual.