The Impact of Linguistic Distance on Dyslexia in Dialect Speakers: The Case of Arabic Diglossia

Arabic native speaking children across the world grow up in a sociolinguistic context called Diglossia (Ferguson, 1959). In this context, two language varieties are used within the same speech community for two sets of complementary functions: Spoken Arabic (SpA) for informal speech and (Modern) Standard Arabic (MSA, StA) for formal speech and reading/writing. Consequently, all Arabic speaking children learn to read in a language variety that is different from the spoken variety/dialect they use for everyday speech. The two language varieties are linguistically related, yet different in all domains of language, notably in phonology and lexicon. Research addressing typical reading in Arabic reveals the impact of linguistic distance (specifically lexical-phonological) on reading skills development. The chapter reviews recent research addressing the impact of linguistic distance on dyslexia. By manipulating linguistic affiliation and comparing the processing of words and pseudo words that preserve the same lexico-phonological form in SpA and in StA as against those that are different in the two language varieties, researchers demonstrated a significant and persistent effect of distance on word-level reading (accuracy and fluency), phonological memory and word learning in Arabic speaking children with dyslexia as compared to age-matched controls. These results imply that the linguistic distance between the written language variety and the spoken dialect is a factor of complexity that interferes with linguistic processing and with reading in Arabic dialect speakers with dyslexia.