The science of reading has made significant progress over the past several decades in understanding the mechanisms behind reading as well as identifying reading universality and specificity. Of particular interest are research findings converging on two areas: (1) varied reading processes across scripts and (2) crosslinguistic influences. Firstly, since script is at the core of reading, each script’s characteristics regulate the way in which written text is processed. Writing systems are derived from spoken languages to represent the units of language in a systematic way. As the manner in which linguistic units are encoded in the writing system varies, the script, which refers to “the graphic form of a writing system” (Coulmas, p. 454), is bound to differ across writing systems. Secondly, the notion of crosslinguistic influences has been well documented in the literature. Linguistic schemata acquired in the native language exert substantial effects on learning an additional language. The same goes for cross-scriptal effects on reading in another script as the consequences of reading in the script that was learned first.
Differential reading processes and their impacts on cognition as the results of the script being read and cross-scriptal influences can be explained through a lens of the script relativity hypothesis (Pae, 2020, 2022). The script relativity hypothesis posits that the specific graphic form and extralinguistic characteristics of writing systems, including letter shape (e.g., ascenders, descenders, dots, and curves), letter/graph configuration (Roman letters vs. Non-Roman graphs), syllable (or character) formation (linearity vs. block), diacritics or circumflexes (marks used above or below a letter to indicate contraction, accent, pitch, tone, or length), word constituents (simple or compound words), spatial relations (the degree of crowdedness within a character), and syllabic format (horizontality or verticality as particulary shown in Korean Hangul and some Chinese characters), yield considerable effects on mental processes, such as thinking (action of reasoning), thought patterns (product of thinking), recognition, conception, inference, and worldview (Pae, 2022). Crucial in the script relativity hypothesis is the isolation or differentiation of true scriptal effects from linguistic effects on these dimensions. Given the interlocking relationship between spoken language and written language, research findings in the science of reading tend to be at the confluence of both modalities of language. The graphic form and extralinguistic characteristics of writing system, as described above, have little connection to linguistic features, but still theoretically and pragmatically affect cognition. Therefore, scriptal effects are not utterly subsidiary to linguistic effects. This point warrants systematic research in the science of reading.
Systematic research to identify true script effects can further advance reading science when the coverage of scripts being researched is balanced across scripts. The skewness in research has been pointed out by Share (2021), as the body of knowledge established in the science of reading is primarily from European alphabets. Share (2021) laments that mainstream reading research still centers on Anglocentrism, Eurocentrism, or alphabetism. Considering that a large portion of the population worldwide reads and writes in non-European, nonalphabetic scripts, such as consonantal abjads (e.g., Arabic, Hebrew), alphasyllabic abugidas (e.g., Hindi), and morphosyllabaries (e.g., Chinese, Japanese Kanji), more research in these scripts is needed.
In the spirit of addressing the necessity of disentangling true script effects from linguistic effects as well as covering non-European writing systems, this special issue includes a collection of studies of script relativity effects in non-European scripts. Eight papers are included in this special issue involving Chinese, Japanese, Korean, and Hindi, along with a review focusing on Thai.
Each paper defines terms used within the article. However, for continuity, the terms, writing systems, orthographies, and scripts, are defined as follows, unless otherwise noted in a given paper. Coulmas (1999) explains an overlapping but differentiating meaning for writing systems and scripts by claiming that “a writing system needs a script for its physical representation, but both are conceptually independent of each other” (p. 454). A writing system refers to a set of written signs used to encode the unit of spoken language. An orthography is “a normative selection of the possibilities of a script for writing a particular language in a uniform and standardized way” (Coulmas, 1999, p. 379). An orthography is language specific and is often codified by official decree for orthographic regulation. According to Coulmas (1999), the term orthography covers systematic rules for both graphotactics and grapheme-phoneme correspondence. A script refers to the physical representation of a writing system. The same writing system can have different scripts. For example, the alphabet (referring to a writing system) includes multiple scripts, such as the Roman, Cyrillic, Greek, Russian, and Korean Hangul scripts.
Winskel (2022) opens the discussion in this issue by critically reviewing the literature focusing on spatial arrangement and layout of the script as well as the presence or absence of phonological diacritics for lexical tones particularly in the Thai script. She compares nonlinear scripts, such as Chinese, Sinhala (a nonlinear Brahmi-derived script), and Japanese, with respect to attention allocation or selective channeling of attention, visual identification patterns, and adaptive specialized process during reading. Habitual reading in a script with a particular spatial layout and with varied lexical tones seems to affect attention, visual discrimination, and other cognitive processes. Empirical evidence gleaned from previous research points toward script-on-cognition effects, supporting a weaker version of the script relativity hypothesis. Given that previous studies were not purposely designed to examine script-specific effects by controlling for language-specific effects, Winskel (2022) calls for more systematic research designed to unfold script effects beyond linguistic effects. She also suggests that further carefully designed studies should be conducted in lesser studied languages and scripts to better understand the script-cognition connection.
Taking advantage of biscriptal use in Chinese, Georgiou et al. (2022) investigated how learning to read in two scripts simultaneously, including Chinese characters and pinyin (a Romanized phonetic coding system), would yield an impact on vocabulary learning and word reading over time. The results of a cross-lagged analysis showed differential associations between vocabulary and word reading from kindergarten to Grade 3. Acquiring mophosyllabic characters resulted in reciprocal relationships between those two skills from kindergarten to Grade 2. However, longitudinal relations between pinyin reading in kindergarten and vocabulary acquisition in Grade 2 were only unidirectional. These results demonstrate that differential script effects take place even among young readers or emergent readers. This finding provides foundational support for script relativity, indicating that the basis on which script effects rest can be established at the beginning of literacy.
Another study with young readers was conducted to address the script relativity hypothesis. Lui and colleagues (2022) investigated how skills in Chinese and English were related to arithmetic skills. Given that the scriptal features of Chinese and English are dramatically different from each other, if significant relationships were found, it would serve as evidence for script effects on the manipulation and operation of numbers or numeric processing. Lui et al. compared performance among four groups formed based on two proficiency levels (high vs. low) and two scripts (Chinese vs. English), including the groups of good in both scripts, poor in Chinese, poor in English, and poor in both scripts. Significant group differences were found in almost all cognitive-linguistic skills, including phonological awareness, morphological awareness, vocabulary, and rapid digit naming, along with Raven’s test, backward digit span, arithmetic calculation, and word reading measures. The main finding was that the poor-in-Chinese group showed lower arithmetic skills than the poor-in-English group, suggesting that the poorer character reading, the poorer arithmetic skills. The gap between the good-in-both-scripts group and the poor-in-Chinese group suggests considerable associations between Chinese reading and arithmetic skills. These findings chime with Logan’s (2004) claim that Chinese people tend to be better in arithmetic and algebra than Westerners due to the Chinese writing system. According to Logan (2004), the Chinese made significant progress in arithmetic and algebra, while Westerners made substantial advances in geometry. The findings of Lui et al. are also consistent with the notion of the script relativity hypothesis.
In a study with adults, Wang et al. (2022) investigated how skilled Chinese readers consolidated irrelevant meaning cues provided by radicals to the meaning of the character (i.e., irrelevant meaning from the radical to the character) in semantic categorization, using an auditory semantic relatedness judgment task. They found that Chinese readers made use of the meaning of the radical that was even unrelated to the meaning of a given character. Wang et al. suggested that sustained experience with the idiosyncrasies of the script impacts how readers utilize scriptal information provided at the sub-lexical level, even irrelevant information, in eliciting the meaning of the character.
Another adult study investigated crosslinguistic influences focusing on how schemata established in readers’ L1 writing system would regulate the development of L2 reading and how L2 linguistic skills (vocabulary and grammar) would constrain cross-scriptal effects. Li and Koda (2022) examined the relative contributions of form-based word analysis skills, such as orthographic, grapho-phonological, and grapho-morphological subskills, to semantic retrieval and reading comprehension in L2 among native Chinese college students with English as their L2. While the orthographic subskills were significantly related to semantic retrieval, grapho-morphological processing subskills were predictive of reading comprehension in L2. Importantly, L2 linguistic skills mediated the pathways to semantic retrieval and reading comprehension in L2, suggesting that a certain level of threshold skills was required to make use of L1 schemata for L2 reading. Overall, the authors found coalesced interactive effects of preexisting L1 script-schemata and sequentially developing L2 proficiencies. These findings were interpreted from the perspective of script relativity effects.
A piece of evidence from reading in Japanese adds another insight into script relativity. Inoue et al. (2022) provide findings that, notwithstanding learning to read in two different scripts concurrently, the characteristics of each script demonstrate different cognitive functioning even among children. They investigated the role of the two scripts of Japanese (i.e., phonosyllabic Hiragana and morphographic Kanji) in cognitive skills (i.e., rapid automatized naming, visuospatial skills) and linguistic skills (i.e., vocabulary and morphological awareness) as well as reading fluency and word recognition from Grade 2 to Grade 3. Their findings support the claim that the nature of the script being learned by children can shape the way in which cognitive profiles are established.
Kim and Cao (2022) investigated brain circuitry and functioning in reading Korean, Chinese, and English, given the dramatic differences in the three scripts. They found some commonalities in brain activation in reading Korean and Chinese, but differences between English and the two East-Asian scripts (i.e., Korean and Chinese). This finding is noteworthy because both Hangul (the Korean script) and English rely on the alphabetic principle for syllable formation. Although the alphabet is the operating principle for both English and Korean, it seems that the visually different script configuration between those two scripts (i.e., linearity vs. block) overrides the alphabetic principle. Kim and Cao concluded that these findings could be attributable to the syllable-based representation and processing of Hangul. These results directly point toward script relativity effects, suggesting that the specific graphic form and extralinguistic characteristics of writing systems mentioned earlier outweigh the effects of operating principles.
The last article is about reading in bi-scripts focusing on the Hindi script. Singh et al. (2022) used a masked priming paradigm to investigate the effects of script romanization among Hindi-English bilingual readers, in which the participants were primed with interlingual homophones in Devanagari (traditional Hindi script) versus Romanagari (Romanized Hindi script). Participants were faster at English L2 word recognition when primed by homophones in Romanagari than in Devanagari. In addition, a greater phonological priming effect was shown on the primes with diacritics for the original Hindi script as well as the Romanized script where the diacritics were not marked. English L2 and Devanagari L1 proficiency predicted unique variance in phonological priming. These results provide converging evidence for the influence of adopting a different L1 script in bilingual processing and that script differences play an important role.
Although the above studies have tackled script relativity effects in various scripts, this line of research needs to continue. Another area of studies can focus on processes at the sublexical and lexical levels with and without circumflexes and suprasegmental properties because sound-symbol mapping, visual exploration, and script-to-text integration are by and large dependent on the graphophonic representations of a particular script being read and because brain circuitry and networks are further arranged differently depending on the script being read over time (Kim & Cao, 2022). The presence of circumflexes or diacritics in Arabic and Hebrew as well as tone markers in pinyin, Thai, Lao, Myanmar, and Vietnamese can affect the allocation or shift of readers’ attention. Eye-movement research can capture readers’ recognitive behaviors associated with these features to investigate whether protracted reading in scripts that have these features leads to readers’ heightened visuo-perceptual abilities in a comparative study of readers whose scripts do not present such features.
Future research can also quantify the degree to which writing systems align with spoken languages (e.g., sound-symbol association or mapping, morpheme-grapheme correspondence), as the way and degree in which a logographic writing system aligns can be much different than an alphabetic one. Since writing systems exist to represent the units of spoken language in a systematic way for information transmission (inter- and intra-personally), this line of studies will allow for an identification of modality differences across scripts and further contribute to a better understanding of script relativity effects. In addition, as Winskel (2022) points out, the effects of reading in densly packed scripts (e.g., traditional Chinese characters), in comparison to less densly packed scripts (e.g., simplified Chinese characters, Roman alphabets), can also be examined to identify whether and to what extent reading in such scripts promotes visuo-perceptual skills and visual discrimination skills.
Queries on the role of aural and non-aural modalities in reading and further in the consequences of reading can extend to sign language. Sign language studies can particularly shed light on the relationships between the visual-manual modality of natural language and reading because sign language relies on the visual medium through gestures and signs with no aural information. The relationship between iconicity (as opposed to arbitrariness) and its meaning as well as its impact on cognition can also be investigated in sign languages because the degree of mimetic properties (signs imitate or mimic the message) is higher in sign language than in spoken language. Another extension can be made to braille literacy. Braille is a tactile writing system used among individuals who are blind or visually impaired for reading and writing. Since braille is designed to read by the sense of touch, reading in braille and print or typical text can be examined to see whether modality differences yield differences in perceptual processing between braille readers and print readers. The role of intensified tactile memory in cognition as a result of braille literacy is worthwhile to be investigated to unpack the effects of braille reading.
Research on habitually learned tendencies and behaviors as a result of literacy is also a fine candidate for examining script relativity effects. For example, Tversky et al. (1991) reported the effects of text direction (left-to-right vs. right-to-left) on children’s tendencies or prefernces in performing activities. They found that, when asked to arrange like, dislike, and favorite food by putting stickers on a blank page, English-speaking children showed tendency to put stickers in the left-to-right orientation, whereas Arabic-speaking children preferred to arranged them in the right-to-left direction, just like their text or reading direction. These results support the notion that readers’ preferences and behaviors can vary depending on scripts being read as a consequence of literacy. All in all, research into the effects of reading on cognition and beyond not only allows us to identify reading universality and specificity, but also promotes our understanding of the mechanism of our information processing and cognitive profiles; thus promoting progress and advances in the science of reading.