An agent-based model of sign language persistence informed by real-world data

As evidence from sign languages is increasingly used to investigate the process of language emergence and evolution, it is important to understand the conditions that allow for sign languages to persist. We build on a mathematical model of sign language persistence (i.e. protection from loss) which takes into account the genetic transmission of deafness, the cultural transmission of sign language and marital patterns (Aoki & Feldman, 1991). We use agent-based modeling techniques and draw inspiration from the wealth of genetic and cultural data on the sign language Kata Kolok to move towards a less abstract model of sign language persistence. In a set of experiments we explore how sign language persistence is affected by language transmission types, the distribution of deaf alleles, population size and marital patterns. We highlight the value of using agent-based modeling for this type of research, which allows for the incorporation of real-world data into model development.