© Gemma Tickle and Michael Bodiam for Mosaic

In 2012, Lina Hou and Kate Mesh were researching Chatino Sign Language, a village sign language used in two small communities in Oaxaca, Mexico. Hou, now an assistant professor of linguistics at the University of California, Santa Barbara, is Deaf; Mesh, now at the University of Haifa in Israel, is not – but both are signers of ASL.

“We started out only writing to one another to avoid using ASL in the community,” says Mesh, but the two slipped up. A lot.

They couldn’t hide it – adult signers in the community noticed the foreign signs immediately.

How did they react? “They thought [ASL signs] were amusing,” Mesh remembers, but she says they never used those signs other than to talk about what the two researchers had done. So she and Hou loosened up around adults, which made communication easier and didn’t affect Chatino signing.

She inadvertently brought other aspects of ASL into her Chatino signing. One day, she was talking with a signer about a basketball contest in the village, in which the prize money came from contributions paid by the contestants.

“Does everybody pay?” Mesh asked. Although she used Chatino signs, she used them with ASL grammar, signing the verb ‘pay’ two times in two different places in front of her body to indicate more than one person paying.

Because Chatino signers don’t have this kind of construction, the man she was speaking to called over his wife, also a signer, and demonstrated what Mesh had done. He liked it, he said. But Mesh says she never saw him sign that way again, not with the verb ‘pay’ or any other verb. To Mesh, it indicated how impermeable signers can be.

Every language has gaps, points out Marie Coppola, a linguist at the University of Connecticut. Even big spoken languages like English, Italian and Chinese do some things well and others not at all. Kinship terms in English aren’t very sophisticated, for example, and there’s always a list circulating on the internet about useful concepts for which English has no word.

In most cases, the people who use those languages may not even recognise what their languages don’t allow them to do – and signers of small sign languages are no different. “All they know is that they have miscommunication, but that’s their whole life,” Coppola says. “They don’t have anything to compare it to.”

Adults are particularly resistant to change, even to external solutions to communication problems they face. This is likely due in part to the challenges of learning new grammar patterns as we get older, though learning new vocabulary is less of a hurdle.

But if, as Mesh discovered, individual outsiders have little influence on emerging sign languages, broad social and cultural trends most certainly do. As previously isolated communities become more connected, speakers adapt their sign languages, and some may even stop using them or passing them on.

And the conditions of contemporary life are ever more hostile to small languages. When Connie de Vos went back to Bengkala in 2012, just six years after her first visit, a lot had changed. Several hundred tourists a year now come to see the signing village, and they pay for food and lodging or make donations to the village.

This newfound wealth means everyone in Bengkala has a motorbike, which many use to work farther from the village – it also means younger men are more likely to marry women outside the community than before. Some deaf kids started attending a school where they learned BISINDO, the national Indonesian sign language. It’s hard to see how one researcher could have had anything like the influence of the changes resulting from the tourists. Ironically, many of these tourists are themselves deaf.

Will Kata Kolok survive? The history of human language itself is littered with unique varieties that spring up, flourish and then wither. The example of another village sign language shows that for some, isolation from the outside world ensures their survival, and that active new strategies will be needed to keep them alive when that isolation disappears.