Culture Before Genes: The Case of a Village Sign Language

Village sign languages are small sign languages used within a village or a small community. Unlike national sign languages, such as American Sign Language or Japanese Sign Language, which have large populations of mostly unrelated signers, village sign languages typically arise spontaneously in communities with endogamous or consanguineous marriage practices. Some village sign languages have emerged only recently, allowing linguists, anthropologists and geneticists to study how a new language can emerge and persist in more than one generation. An example of a village sign language where both endogamy and consanguinity is practiced is Al-Sayyid Bedouin Sign Language (ABSL), used in a southern Israel community of about 3500 deaf and hearing Bedouins. ABSL is now approximately 75 years old, and first emerged in a family with 4 deaf siblings. After this first generation of deaf signers, all of whom are deceased, there are about 30 deaf signers in the second generation, about 80 in the third, and a fourth generation is just now being born into the community. Unlike the case of another small sign language, Amami Sign Language in Japan where the language is used by a few families and a small number of signers, ABSL is widely used across many families in the village. Endogamy and consanguinity together with recessive deafness in a community explain the number of deaf members in the village, but the presence of other cultural practices, such as close in-group ties, frequency of deaf-hearing marriages, and a high birth rate, results in a large number of hearing signers who use ABSL as a second language in addition to Arabic. A high birth rate in the community has the effect of increasing the number of deaf children as well as hearing siblings close in age who become signers.  The availability of multiple deaf and hearing adult and peer models of sign language results in broad access to the language for the next generation of young children, both deaf and hearing. Comparative studies of ABSL and other village sign languages yield real-world data that can be used to develop  - and constrain  - potential models for language emergence, transmission and persistence in a human community.