Sign languages for the deaf exist today in almost all countries and regions. Linguists have now reconstructed when and how the different variants of gesture communication emerged and in what context. Their results underscore the important role that the European Enlightenment and the associated educational measures played in the spread of these gesture languages.
Non-verbal communication via gestures is not a modern invention: Our early ancestors probably used hand signals for wordless communication. However, the sign languages used all over the world emerged much later: a large part of them were developed in the late 18th and early 19th centuries. A complex system of word characters including grammatical variants gradually emerged from letter characters.
Subtle differences reveal the family tree of sign languages
But what are the origins of the various modern sign languages? “While the evolution of spoken languages has been studied for more than 200 years, research into the development of sign languages is still in its infancy,” says lead author Justin Power of the University of Texas at Austin. “Much of what we know about the stories of sign languages in use today is based on historical sources that describe the contact between deaf institutions and teachers. We wanted to know how a comparison of sign languages using current and historical sources could shed new light on the development and spread of European sign languages. ”
For their study, the researchers performed a comparative analysis of 40 modern and 36 historical manual alphabets. They compared subtle variations of the individual gestures between the languages - similar to how a geneticist compares mutations in the genome. “In both biological and linguistic evolution, characteristics are passed on from generation to generation,” explains Power. However, there are always small changes. The more similar individual gestures in the different sign languages are, the more likely this is to indicate a close relationship and a common origin.
Paris as the European center of enlightenment and sign language
The results confirm the close link between European education and its educational ideals with the spread and further development of sign languages. “The establishment of educational facilities for the deaf began during the education in Europe in the late 18th and 19th centuries,” said Power and his team. At that time, Paris was one of the centers of this educational education: “The success of the first public school for the deaf, the Institut National de Jeunes Sourds de Paris, founded between 1759 and 1771, attracted educators from all over Europe and the New World,” said the researchers. “The educators came to the Paris Institute to learn pedagogical methods and then to set up their own deaf schools in their home countries.” The students of the institute also came from all over Europe and thus contributed to the spread of the sign language practiced there.
This is confirmed by the comparative analysis of the signs. Accordingly, the French sign language forms the origin of one of the five main groups of modern sign languages. It has shaped the development of numerous European, but also American and international sign languages, as Power and his colleagues found. In the Paris deaf community, the first old Spanish letter characters were developed further in such a way that a sign language emerged from them. But in addition to the French sign language, there was another one that already had a surprisingly great influence at the end of the 18th century: Austrian sign language. “It is known from historical sources that the founders of the first deaf school in Vienna, Joseph May and Friedrich Storch, visited the Paris Deaf Institute in 1777 to learn pedagogical methods and later to advance the education of the deaf in the Habsburg Empire,” reports Powert and his team. Therefore, it was previously assumed that the Austrian sign language developed from the French.
But the character analyzes reveal this as a mistake. According to the study, both languages have their origin in the Spanish hand signals, but they were created independently of one another – one in Vienna, the other in Paris. Based on the early Austrian sign language, the language variants of Poland, Hungary and Russia also developed in the early 19th century. Some Scandinavian sign languages can also be traced back to Austrian roots, as the researchers found.
Source: University of Texas at Austin; Technical article: Royal Society Open Science, doi: 10.1098 / rsos.191100