Introduction

In recent decades, studies have shown that SES has a significant impact on children’s reading accuracy and comprehension in alphabetic languages as well as in Chinese (Cheng & Wu, 2017; Hart et al., 2013; Noble et al., 2006). Compared to the role of SES in children’s reading ability in their first language (L1), less is known about how it influences reading development, especially in the later stage of development, and in their second language (L2, for a review, see Liu et al., 2016). The present longitudinal study aimed to investigate these issues by looking at children learning two languages (i.e., Chinese, which is generally considered as a logographic script, as their L1 and English, an alphabetic script, as their L2). These two languages have substantial differences, such as orthography-phonology correspondence and morphological structure.

Previous research has identified a number of cognitive and language skills, including phonological awareness, orthographic awareness, rapid naming, morphological awareness, and vocabulary knowledge, as important predictors of literacy development in both alphabetic and logographic scripts such as Chinese (e.g., Lervåg & Aukrust, 2010, Lyytinen et al., 2006, McBride-Chang et al., 2012; Nagy et al., 2003; Shu et al., 2006). Besides the abovementioned variables, SES has been shown to predict reading performance in different languages (Noble et al., 2006; Su et al., 2017; Zhang et al., 2013). SES usually refers to parental income, education level, and occupation. Fung and Chung (2020) found that SES predicts both the reading and the writing of Chinese children. Previous studies have shown that children from high SES families show better pre-reading and language skills before receiving formal education than do their peers from low SES families (Hecht et al., 2000; Hoff, 2003; Rowe et al., 2012). It influences home literacy environment and resources, such as toys and books available, neighborhood and school choices (e.g., Liu et al., 2020; Van Steensel, 2006). Teacher quality, friends’ influences on literacy attitudes, and even country-level literacy skills are all partly a function of SES at different levels (e.g., Chiu & McBride-Chang, 2006). Previous findings suggest that the influence of SES on children’s literacy environment is mediated by other factors such as phonological awareness and vocabulary (Farkas & Beron, 2004; Noble et al., 2006; Zhang et al., 2013).

To our knowledge, most studies have investigated the association between SES and L1 learning (also see Liu et al., 2016 for a review). Only a very small number of studies have investigated how SES affects L2 learning (e.g., Kahn-Horwitz et al., 2006), and these results are inconsistent. For example, Páez et al. (2007) studied 4-year-old Spanish-English children living in the United States and found that SES was equally related to literacy skills in both L1 Spanish and L2 English. However, Bohman and colleagues (2010) found that, among Spanish-English bilinguals, children from higher SES families had better language performances in L2 English whereas children from lower SES families, who were likely recent immigrants to the US, had higher language performances in Spanish.

The above-mentioned studies mostly explored bilingual children speaking two alphabetic languages where their L2 was the official language in their countries of residence. It is less clear how SES contributes to reading development in two very different scripts (e.g., alphabetic and logographic scripts), especially when L2 is used less commonly than L1. This, nevertheless, is important because, in many societies, it is mandatory for students to learn a L2 which is used less often than the L1. For example, in mainland China, all students have to take one foreign language exam to fulfill the college entrance exam requirement (Ministry of Education of the People’s Republic of China, 2023); the majority of them take the English exam (Li et al., 2021), followed by Japanese (about 2% of the total number of students taking the college entrance exam, ** children’s phonological sensitivity even in a nonalphabetic language and script. Noble et al. (2006) proposed that advantaged parents are more likely to notice children with weak phonological awareness and to have the resources to increase the children’s exposure to phonological activities or to use alternative educational strategies, leading to better phonological awareness of their children as compared with those from low SES families. In addition, SES also affects vocabulary acquisition. Oral vocabulary provides the basis for children to learn print-sound correspondences. Previous research has shown that children from higher SES backgrounds are more likely to have encountered larger numbers of words through the high quality of parent-child interactions, such as shared book reading, which has been shown to help in learning new vocabulary (Hood et al., 2008); These activities are shown to have a positive influence on reading development (Wood, 2002). These factors may also be valid in the Chinese context. Phonological awareness has been shown to influence the development of vocabulary, morphological awareness, and reading accuracy among Chinese children (Pan et al., 2011, 2016; Song et al., 2015). Vocabulary knowledge also lays the foundation for learning printed words in primary education. Children’s vocabulary development has been found to be associated with their mothers’ education levels (Song et al., 2015). Parents from higher SES families may be more likely to conduct more home-based literacy-related parent-child activities, and provide more resources in supporting their children’s learning processes, which in turn, boost their phonological awareness and vocabulary knowledge. Our findings that vocabulary knowledge acted as a mediator between SES and Chinese word reading in primary school differed from the finding reported by Liu et al. (2016) that kindergarteners’ vocabulary knowledge did not mediate the relationship between SES and Chinese word reading. This could be because, as children grow older, reading focuses more on processing meaning. Thus, children’s vocabulary knowledge becomes more important in the later stages of their development (Pan et al., 2016). Another reason might be that an expressive vocabulary test was used in our study, while a receptive vocabulary test was used in Liu et al. (2016).

Our findings show a slower quadratic trend in Chinese word reading development in the children from higher SES families. This might be explained by the higher starting points and faster linear development trends of those from higher SES families leading them to have mastered most of the words earlier; this could result in the slower quadratic trend observed in this study.

In comparison to the indirect effects of SES on L1 Chinese word reading, the present study documented a stronger and direct association between SES and L2 English word reading. Previous studies on the influence of SES on bilingual children’s reading development have focused on children learning two alphabetic languages, with L2 as the official one in their society. The current study, together with a few studies conducted in Hong Kong (Li et al., 2012; Liu et al., 2016; McBride-Chang et al., 2012; Zhang et al., 2014) has added to our knowledge about the influence of SES on bilinguals learning two very different languages (i.e., one logographic and one alphabetic) with L1 being the main language at home and in society. The current study also expands our knowledge in terms of the long-term influence of SES on L2 English in Chinese societies.

Although we showed a direct effect of SES on English word reading in mainland China, which is in line with findings from Hong Kong (Liu et al., 2016; McBride-Chang et al., 2012), we speculate that the mechanisms behind this relation might be different in the two places. Other studies have found that children from high SES families received more scaffolding at home through daily communications in English with their parents (Chow et al., 2010) and foreign domestic helpers (FDH, Dulay et al., 2017) in Hong Kong. Given the small amount of people in mainland China with enough English knowledge to converse fluently in English (3.53% according to Wei & Su, 2012), children may not be able to receive much direct scaffolding at home. However, this does not necessarily mean that mainland Chinese parents do not consider English to be important. Rather, they may rely on external resources, such as English-speaking tutors and tutorial centers, to improve their children’s English. This is supported by previous research which showed that more than 73.8% of primary students participated in some private tuition activities in mainland China (for a review, see Kwok, 2010). Zhang and **e (2016) found that children from higher SES families were more likely to attend private tutoring and their parents were more likely to spend higher levels of tuition fees. These children tended to have higher academic achievement. These external tuition resources are also popular in Hong Kong, but there it is often in addition to daily parent-child communication in English and the presence of English-speaking FDHs in homes. Nevertheless, such tuition is less prevalent among primary students (36%, see Kowk, 2010 for a summary). Future studies are needed to investigate whether this explanation is valid.

Besides the direct effect of SES on English reading, we also demonstrated indirect effects through English letter name knowledge and phonological awareness. Children from higher SES families might have more exposure to English, thus it is not surprising to see the mediation effect of English letter name knowledge. However, our phonological awareness task was measured in Chinese. This appears to suggest some transfer from Chinese phonological awareness to English word reading. This is consistent with findings of Tong and McBride-Chang (2010), that phonological awareness (measured by syllable deletion) in Chinese (L1) significantly predicted English (L2) reading in Hong Kong Chinese children. In general, our findings support the idea that phonological transfer might be possible even between languages with very different phonological structures (Chow et al., 2005; Gottardo et al., 2001; Saiegh-Haddad & Geva, 2008).

Vocabulary knowledge mediated the association between SES and Chinese, but it did not contribute to English word reading. In addition, it was mainly phonological sensitivity that mediated SES and English word reading. Taken together, these strongly indicate that the nature of a language is reflected by the skills needed for its acquisition and development. Chinese is a logographic script which emphasizes meaning, while English has a phonological nature. In line with this point of view, McBride-Chang et al. (2005) found, in a cross-language comparison, that morphological awareness and vocabulary were important for Chinese children’s literacy development, that both morphological awareness and phonological awareness were important for learning Korean, but only phonological awareness contributed to English reading. Previous studies have also shown that adult Chinese readers can access semantics, bypassing phonology (Zhou & Marslen-Wilson, 2000; Yan et al., 2009), while the recognition of alphabetic words follows the sequential activation from orthography to phonology to semantics (Van Orden, 1987).

From a theoretical perspective, our findings extend work by Liu et al. (2016) with kindergarten to upper primary school children, suggesting a long-lasting influence of SES on literacy development, especially in L2. Our findings are also in agreement with the Family Stress Model (Iruka et al., 2012; Masarik & Conger, 2017) that SES affects academic achievement. Future studies might further explore whether this phenomenon of resources being associated with L2 reading is universal. Such different patterns in the association of SES with L1 and L2 reading also have practical implications. To help students from poor families to learn English, additional support from school would be beneficial, as they do not have as much as resources to go to tuition centers or hire private tutors like their richer peers do. Special teaching strategies need to be designed and extra English books and other resources could be provided for these children, to increase their exposure to English.

The present study has the following limitations. First, early English phonological awareness and vocabulary knowledge were not measured. Second, we did not measure SES again at a later stage. As the SES was reported by parents when the children were one year old, it is not clear how later changes in family SES could affect their literacy development. Another limitation is that the current study was part of a longitudinal study commenced around 2000, when the participating children were born, which may have affected the interpretation of the findings and the impact of the study. However, given previous findings that the influence of SES on academic attainment lasts from childhood to adolescence across different countries (for a review, see Chen et al., 2018), we consider the current findings to be useful in understanding the impact of SES on literacy development. The findings of the current study might be generalizable to other societies in which children are required to learn a L2 which is less commonly used, but it is nevertheless a very important language for their academic attainment.

To summarize, we tested the associations between SES and word reading in Chinese (L1) and English (L2) in children from ages 7 to 11 years. Our results suggest that SES is important for reading in both scripts. Our results also suggest that more support in linguistic skills is important for children from low SES backgrounds to learn Chinese. In addition, it is important for teachers and educational policy makers to consider proper assistance to help children from low SES families to keep up with their more wealthy peers, given the importance of English globally in certain education sectors.