Writing System Variation and Its Consequences for Reading and Dyslexia

ABSTRACT

Most current theories of reading and dyslexia derive from a relatively narrow empirical base: research on English and a handful of other European alphabets. Furthermore, the two dominant theoretical frameworks for describing cross-script diversity—orthographic depth and psycholinguistic grain size theory—are also deeply entrenched in Anglophone and Eurocentric/alphabetocentric perspectives, giving little consideration to non-European writing systems and promoting a one-dimensional view of script variation, namely, spelling–sound consistency. Most dyslexics struggle to read in languages that are not European and orthographies that are not alphabetic such as abjads, abugidas, or morphosyllabaries; hence the full spectrum of the world’s writing systems needs to be considered. The global picture reveals multiple dimensions of complexity. We enumerate 10 such dimensions: linguistic distance, nonlinearity, visual complexity, historical change, spelling constancy despite morphophonemic alternation, omission of phonological elements, allography, dual purpose letters, ligaturing, and inventory size. We then consider how these 10 dimensions might affect variation in reading ability and dyslexia.

Notes

¹ The phonetic components in Chinese would appear be the most extreme case of historical script/speech divergence, but unlike phonemic scripts, for which the primary (and often only) cues to the identity of an (isolated) word are sound, Chinese operates very differently from the alphabetic scripts familiar to Europeans by supplying the reader with meaning-based cues to word identity in the form of the semantic radical—as the descriptor “morphosyllabic” denotes. Thus the phonological ambiguity of Chinese phonetics carries far less weight in Chinese word learning and word identification compared to English and other European scripts.

² In Hebrew, however, the morphological primacy of consonantal phonemes reduces the importance of vowels, as seen in limited sensitivity of native speakers to vowels in spoken words (Ravid, 1995), and diminishing knowledge of written vowel signs as reading proficiency grows (see Share, 2017). This implies that in Semitic abjads, impaired vowel awareness should not impede reading—thus there may be excellent readers of abjads who are unable to perform “full” phoneme segmentation (consonants and vowels, see, e.g., Ben-Dror, Frost, & Bentin, 1995; Share & Blum, 2005) and who, consequently, may experience unique difficulties with an alphabetic script such as English where vowel awareness may be as essential as consonant awareness. The precise nature of the weaknesses in phonological awareness (units and timing) among disabled readers is heavily dependent on language and orthography.