Martha’s Vineyard Sign Language (MVSL) developed because an unusually high number of deaf residents were born on the island over several centuries, the result of a recessive gene carried by founding families who all traced their roots to the same small region in England. Geographic isolation kept the gene pool concentrated, deafness became common enough that everyone needed a shared language, and hearing residents learned to sign right alongside their deaf neighbors.
A Recessive Gene From Kent, England
The story begins not on Martha’s Vineyard but in a rural area of southeastern England called the Weald, in the county of Kent. Several families who settled on the island in the 1600s came from this same small community, and they carried a recessive gene for deafness. Among them was Jonathan Lambert, one of the first documented deaf settlers, whose parents came from the Weald. Because the gene was recessive, a person needed to inherit a copy from both parents to be born deaf. That was unlikely in a large, genetically diverse population, but on a small island where intermarriage among a limited number of families was common, the odds increased dramatically.
This is what geneticists call a founder effect: a small group of original settlers passes along a trait that becomes far more prevalent in their descendants than it would be in the broader population. Over generations, more and more Vineyard children were born deaf, not because of any disease or environmental cause, but simply because the math of inherited genes on a small island made it inevitable.
Deafness Rates Far Above the Mainland
By the 19th century, the numbers were striking. Across the entire island, roughly one in every 155 people was born deaf. The national rate at the time was somewhere around one in 5,728. In the western, more isolated towns, the concentration was even higher. In Tisbury, the ratio was about one in 49. In Chilmark, the most remote town on the island, it reached one in 25. That meant in Chilmark, nearly every extended family had at least one deaf member, and many had several.
At those rates, deafness wasn’t a rare condition that set people apart. It was an ordinary fact of community life, as unremarkable as being left-handed. And that ordinariness is exactly what made the island’s response so unusual.
Why Hearing Residents Learned to Sign
In most communities during this era, deaf people were isolated, excluded from conversation, and often sent away to institutions. On Martha’s Vineyard, the opposite happened. With so many deaf neighbors, relatives, and coworkers, hearing residents had a strong practical incentive to learn sign language. And they did, fluently and casually.
Both deaf and hearing residents signed with each other with ease. Hearing Vineyarders used sign language not just when a deaf person was present but sometimes among themselves, to communicate across a noisy room, at a distance across a field, or during church services. Signing was woven into everyday life so thoroughly that deaf residents participated fully in the social and economic world of the island. They held jobs, owned property, married, served in local government, and were not treated as disabled in any meaningful social sense.
Researchers who have studied communities like this, where high rates of deafness produce a shared sign language among hearing and deaf people alike, consistently note the same pattern: a relative lack of disablement. The disability, in other words, was not in the person. It was in the communication barrier, and when that barrier disappeared, so did the social disadvantage.
How Island Geography Shaped the Language
Martha’s Vineyard’s isolation played a dual role. First, it kept the gene pool small enough for hereditary deafness to concentrate over generations. Second, it kept the signing community intact and self-sustaining. The island was not easy to reach, especially in earlier centuries, and residents had limited contact with mainland deaf communities or their sign systems. MVSL evolved organically on the island itself, shaped by the people who used it daily rather than imported from any school or institution.
This made MVSL a distinct language, separate from the sign languages developing elsewhere in the United States. It had its own vocabulary, grammar, and regional variations. It was a true community language, passed down in homes and neighborhoods rather than in classrooms.
MVSL’s Influence on American Sign Language
When the American School for the Deaf opened in Hartford, Connecticut, in 1817, Martha’s Vineyard sent a disproportionate number of students. In fact, the island contributed the largest group of deaf students from any single geographic area. These students attended the Hartford school for roughly a century, bringing MVSL with them and mingling it with the French Sign Language system that the school’s founders had introduced.
That blending of MVSL, French Sign Language, and the home signs of deaf students from across the country is part of what eventually became American Sign Language. MVSL is recognized as one of the direct influences on ASL, meaning the language born on a small New England island left a lasting imprint on how millions of deaf Americans communicate today.
Why the Language Disappeared
MVSL’s decline tracked with the same forces that made it possible in the first place, only in reverse. As the 19th century progressed, the island became less isolated. Better transportation brought new residents who didn’t carry the recessive gene, and younger Vineyarders increasingly married people from the mainland. The genetic bottleneck that had sustained high deafness rates gradually opened up, and fewer deaf children were born with each generation.
At the same time, deaf children were more likely to leave the island for education at residential schools, where they joined larger signing communities and often settled on the mainland. The tight-knit, bilingual community that had sustained MVSL for over two centuries slowly thinned. The last native islander carrying the hereditary deaf genes, Eva S. West-Look, died in 1950. The last person known to have used Martha’s Vineyard Sign Language was Katie West, who died in 1952. With her death, MVSL effectively became extinct as a living language.
The entire arc, from the arrival of a few families from Kent to the death of the last signer, spanned roughly 300 years. What made MVSL remarkable wasn’t just the language itself but the kind of community that produced it: one where a genetic trait that the rest of the world treated as a deficiency was simply absorbed into daily life, met not with exclusion but with adaptation.