Wittmann (1991)[2] posits that SSL is a language isolate (a 'prototype' sign language), though one developed through stimulus diffusion from an existing sign language.
References
^Hammarström, Harald; Forkel, Robert; Haspelmath, Martin; Bank, Sebastian, eds. (2016). "Saudi Arabian Sign Language". Glottolog 2.7. Jena: Max Planck Institute for the Science of Human History.
^Wittmann, Henri (1991). "Classification linguistique des langues signées non vocalement." Revue québécoise de linguistique théorique et appliquée 10:1.215–88.[1]
^a Sign-language names reflect the region of origin. Natural sign languages are not related to the spoken language used in the same region. For example, French Sign Language originated in France, but is not related to French. ^b Denotes the number (if known) of languages within the family. No further information is given on these languages.
