Migration background and children’s linguistic abilities

Family background characteristics such as migration background and socioeconomical status (SES) are closely associated with linguistic abilities (Schmidt, 2016). According to the Federal Statistical Office (2022), about 40% of preschool children have a migration background (i.e., the children or at least one of their parents were not born in Germany) and are more prone to language deficits in one or both languages, such as weaker receptive and expressive vocabulary (Eisenwort et al., 2018). Although, about 56% of the families with a migration background mainly speak German at home (Federal Ministry for Family Affairs, Senior Citizens, Women and Youth in Germany, 2020), they often show a poor performance in language tasks and phonological awareness (PA) compared to children without a migration background even before formal schooling begins (Dubowy et al., 2008; Niklas et al., 2011). As a result, children from families with a migration background are disproportionally more exposed to unstable educational trajectories (Autor:innengruppe Bildungsberichterstattung, 2022).

Similar results were also found in German elementary school concerning linguistic competencies such as reading comprehension (e.g., McElvany et al., 2009; Tiedemann & Billmann-Mahecha, 2007), although experts consider German as a language with shallow orthographic depth, and thus easier to learn than, for instance, English (Seymour et al., 2003). One possible explanation for this may be, that German at an early age is hardly or not at all spoken at home in many families with a migration background, but rather the mother tongue of the parents is actively used (Novita & Kluczniok, 2022). In addition, children with a migration background often have no or very little direct contact with the German language before attending the kindergarten (Dubowy et al., 2008). For example, children with a family language other than German often enter kindergarten at an older age (Kohl et al., 2019; Leyendecker et al., 2014) and they also enter primary school with no prior reading instruction required in German kindergarten, making the spoken language at home an important factor for language development and comprehension (Niklas & Schneider, 2017).

For instance, if the family language is not the language of instruction in formal settings, this may lead to deficits in language comprehension (Tiedemann & Billmann-Mahecha, 2007). Moreover, studies indicate that many parents with a migration background are less supportive concerning their children’s learning to read (Niklas et al., 2013) and that they may engage less in reading activities compared to parents without a migration background (Raikes et al., 2006). Consequently, less frequent informal literacy activities may occur within these families which is associated with a poorer receptive vocabulary (Novita & Kluczniok, 2022).

When interpreting these findings, it is important to note that migration background and SES are strongly related in many countries and also in Germany (Weis et al., 2019). For instance, when families with a similar SES are compared, the differences in educational outcomes between children with and without migration background are strongly reduced (Hussmann et al., 2017). However, even when the family SES is controlled for, children with a migration background still face the disadvantages of acquiring German as a second language and show weaker linguistic outcomes such as receptive vocabulary, grammar and reading comprehension (Heppt et al., 2014; Novita et al., 2022).

Whereas research often has focused on SES and its relationship with children’s linguistic abilities, fewer studies considered migration background directly (Niklas et al., 2013; Novita & Kluczniok, 2022). Even though research shows that there are clear linguistic disparities between children with and without migration background (Autor:innengruppe Bildungsberichterstattung, 2022; Dubowy et al., 2008), little is known about the association of migration background with some environmental factors that support children’s linguistic development such as the Home Literacy Environment (HLE). Here, a greater quality HLE may be able to compensate for the disparities associated with migration background.

Facets of the home literacy environment

In the past three decades, numerous studies demonstrated the close association of the HLE with children’s linguistic and social development as well as their academic performance (e.g., Boonk et al., 2018; Bus et al., 1995; Rose et al., 2018). For example, children who grow up in a high quality HLE often show better linguistic competencies (Bonifacci et al., 2022; Lambrecht et al., 2019). The HLE is a multidimensional construct, which includes all the elements, resources, and learning opportunities provided to children (such as shared reading activities, storybook exposure, and parental support in learning) that facilitate the acquisition and development of their linguistic abilities (Burgess et al., 2002; Niklas, 2015).

Bronfenbrenner’s ecological theory (1979) emphasizes the importance of the HLE for children’s linguistic development. It distinguishes between structural and processual influences. Structural characteristics, such as migration background and SES, focus on the framework conditions of language acquisition, while the processual aspects such as the HLE focus more on the processes of learning. In accordance with this theory, structural characteristics of a family such as migration background are closely associated with the HLE, which in turn influence children’s linguistic abilities (Aikens & Barbarin, 2008; Niklas et al., 2013a, b). This means that family background characteristics mainly exert an indirect influence on children’s linguistic abilities, whereby their influence is essentially mediated via the HLE (Lambrecht et al., 2019; Niklas et al., 2013). Consistent with these findings, recent studies indicate that the SES is not (Bonifacci et al., 2022) or only very weakly (Novita et al., 2022) associated with reading comprehension, PA, vocabulary, and letter knowledge.

Consequently, it is reasonable to assume that the direct impact of family migration background on children’s linguistic development is significantly weaker, if the family learning environment includes supportive activities such as frequent and high-quality shared reading (Niklas, 2015).

Yet, little is known about the role of individual facets of the HLE and their impact on children’s linguistic abilities (Inoue et al., 2020). In this study, using the framework of ecological and sociocultural theories, the following four facets of the HLE are analysed in order to determine their mediating role between migration background and children’s linguistic abilities.

Shared reading at home

Reading to children plays an important role in literacy development because it supports the acquisition of language precursor skills such as receptive and expressive vocabulary and PA and promotes children’s motivation to read (Baker et al., 1997; Niklas et al., 2020; Saracho, 2017). In particular, high quality parent-child interactions while reading are positively associated with early language skills such as vocabulary, letter knowledge, grapheme awareness and text comprehension (Raikes et al., 2006; Trivette et al., 2012; Wesseling et al., 2017; Whitehurst & Lonigan, 1998).

In addition, both onset and frequency of shared reading contribute meaningfully to children´s literacy development, in particular to vocabulary, grammatical knowledge, oral narrative skill, letter recognition, and PA (Kotrla Topić et al., 2020; Lenhart et al., 2022; Niklas et al., 2016). Not only the onset of reading and the parental reading behaviour are important, but also children’s own reading behaviour. Wirth et al. (2020) found that children who are frequently read to by others also tend to look often at picture books on their own.

Number of books

The number of books at home is a key aspect of a family’s cultural capital, which includes cultural resources such as books, artwork, or magazine subscriptions (Heppt et al., 2022). A larger number of children’s books contributes to a greater quality of the HLE, as it constitutes a potential learning stimulation and it mediates the relationship between parent’s occupational status and education on one hand and language academic achievement on the other hand (Heppt et al., 2022). Children living in a learning environment that offers broad access to books tend to have a greater vocabulary and a better PA (Niklas et al., 2013).

Knowledge about children’s books

The knowledge about children’s books is found to be a good indicator of the HLE (Burgess et al., 2002; Sénéchal & LeFevre, 2002). Parents who read to their children more frequently have a better and broader knowledge of children’s books (Niklas et al., 2013a, b). The knowledge about children’s books is closely associated with the total reading volume, and it can be assessed reliably with children book title checklists that also include foil titles and thus prevent social desirability answer patterns (e.g., Grolig et al., 2017; Sénéchal & LeFevre, 2002). For instance, Grolig et al. (2017) showed that the score of such a checklist is strongly associated with children’s PA and vocabulary.

Parental attitudes towards literacy

Parents act as role models in the family, and their attitudes towards reading and language also have an impact on their children’s reading behaviour and linguistic abilities. Parents who believe that reading is an entertaining and enjoyable activity, inspire their children with a positive attitude towards reading and thus support children’s linguistic development (Baker et al., 1997). For example, Egan et al. (2022) found positive associations between parent’s reading enjoyment and other facets of the HLE such as the number of books at home and shared reading. Consequently, such positive parental attitudes may enhance the HLE’s quality and children’s linguistic performance (Niklas et al., 2020). Moreover, McElvany et al. (2009) found that both parental attitudes and support were good predictors of children’s academic achievement.

While there is a unanimous agreement that HLE activities contribute to children’s linguistic development, there is still a need to identify how families with a migration background provide a high quality learning environment and opportunities to their children. Moreover, there is still a debate going on about another important aspect of children’s learning environment, namely television exposure (TE), and its potential influence on children’s linguistic and literacy development.

Television exposure

The debate about the use of screens, described as television or screen exposure that are measured with the quantity of TE, has risen in the past decades (Radesky & Christakis, 2016). On average, preschool children in Germany watch television for up to an hour every day or almost every day (Federal Office of Statistics, 2019).

Although children are constantly exposed to television, the consequences of this digital environment are inconsistent in terms of language acquisition and learning. On the one hand, television may offer language input, and thus may positively influence language development. It provides multiple opportunities for promoting language abilities and cognitive skills as children learn not only through direct interaction, but also through observation and listening to others. For instance, Anderson et al. (2001) showed that preschool programmes such as Sesame Street have a positive effect on early linguistic abilities such as letter knowledge. In their systematic review, Kostyrka-Allchorne et al. (2017) found that educational television programmes tend to foster learning, particularly for preschoolers. In addition, TE may help to expand vocabulary knowledge, if screen pictures represent real world objects (Diergarten & Nieding, 2012).

On the other hand, the majority of children usually use television for entertainment purposes, which is, just as an early onset of TE, negatively related to linguistic development (Ennemoser & Schneider, 2007; Kostyrka-Allchorne et al., 2017) and with the HLE (Schmiedeler et al., 2014). Therefore, it has been argued that a high TE is more likely to result in a reduction of important learning opportunities for linguistic interactions (Kostyrka-Allchorne et al., 2017; Madigan et al., 2020). Here, parent-child interactions that promote verbal exchange, children’s language acquisition, and communication are in conflict with TE and the acquisition of linguistic skills may thus be interrupted (Kirkorian et al., 2009). For example, parent-child reading at home occurs less frequently in families whose children have a high TE (Kotrla Topić et al., 2020). Moreover, a high TE at an early age is associated with a greater risk of delayed cognitive, language and motor development (Kannass et al., 2010; Lin et al., 2015) and generally with weaker language skills (Madigan et al., 2020).

Not only the question about quality and quantity of TE seems to be important, but also the situational context while watching television, children’s individual characteristics, and family environment (Kostyrka-Allchorne et al., 2017). Kirkorian et al. (2009) investigated the impact of background television on parent-child interactions and concluded that quality and quantity of parent-child interactions and parental engagement were lower as a result of a television running in the background. Interestingly, Lavigne et al. (2015) found that television co-viewing was negatively associated with the quantity, but positively associated with the quality of parent language directed to the child. In addition, Dore et al. (2020b) found a quadratic relation between the dosage of media use and language gains, indicating that a moderate media exposure was associated with the largest vocabulary development. Moreover, the family SES seems to play an important role. A high background TE exerts a negative effect on children’s vocabulary development in families with a high SES, but it is beneficial for children’s vocabulary, when families have a low SES (Farangi & Mehrpour, 2022). In addition, Leyendecker et al. (2014) found that families with a migration background in Germany reported much higher TE for their children than families without a migration background. These families also attached less importance to reading aloud, their children started attending kindergarten later, and the likelihood of their children participating in parent-child classes or other extracurricular activities was significantly lower, even if their parents belonged to the group with the highest level of education.

Consequently, further research on the quality, quantity and situational context of TE is needed to understand the relationship between TE and children’s linguistic abilities.

Children’s early linguistic abilities

Developing adequate early linguistic abilities is essential for academic success, later career, and the development of complex language skills, such as reading comprehension and writing (e.g., Burgess et al., 2002; Sénéchal et al., 1998). Although formal literacy acquisition in Germany does not begin until primary school, the first language exposure takes place in the family through interaction with parents and siblings within children’s Home Learning Environment (Vygotsky, 1978). For example, parent engagement in home learning activities was associated with children’s school readiness skills (Barnett et al., 2020).

Early linguistic abilities comprise abilities, knowledge and behaviour that include code-related skills such as PA and letter knowledge on the one hand, and oral language skills such as productive and receptive vocabulary on the other hand (Whitehurst & Lonigan, 1998). PA is the ability to recognise the structure of language, mostly operationalized through rhyme, sound recognition tasks or detecting syllables (Suortti & Lipponen, 2016). A meta-analysis concluded that phoneme awareness was the strongest predictor of reading skills, when compared with rhyme awareness and verbal short-term memory (Melby-Lervåg, 2012).

These early linguistic abilities are important precursors of reading and writing. For instance, Schatschneider et al. (2004) found that early linguistic abilities are good predictors of later reading outcomes during the first years of school, suggesting a key role of emergent literacy in the development of children’s later literacy skills. Tamis-LeMonda et al. (2019) also found that receptive vocabulary and letter-word identification at a preschool age were associated with fifth grade academic skills in vocabulary, reading, mathematics and cognition.

Another important precursor is letter knowledge, which is defined as the knowledge of letter names or alphabetic knowledge (Whitehurst & Lonigan, 1998). Mastery of the alphabet enables rapid conversion of written language into sounds and prevents the time delay between letters while reading aloud, which also facilitates reading comprehension (Ehri, 2020; Whitehurst & Lonigan, 1998). These findings emphasize the importance of knowing grapheme-phoneme relations at an early age. For instance, letter knowledge growth during prekindergarten and kindergarten was related to better emergent literacy skills (Carr et al., 2020). Consequently, children who know more letters at an earlier age are also better prepared to learn reading and writing in school (Reutzel et al., 2019). Both, PA and letter knowledge are important precursors of reading comprehension, as these code-related skills enhance word recognition (Hjetland et al., 2020).

Another pathway, which directly improves reading comprehension is vocabulary (Hjetland et al., 2020). It includes semantic, syntactic, and conceptual knowledge (Milton, 2009). A large vocabulary supports children’s later reading comprehension, as it enhances reading speed and reading accuracy (Ennemoser et al., 2012; Joshi, 2005). Consequently, a large vocabulary also enables coherence building in reading, which is necessary for the overall comprehension of a text (McElvany et al., 2009).

Research hypotheses

In this study, the associations between migration background, four different facets of the HLE, children’s TE, and children’s linguistic outcomes were analysed, while controlling for family SES and children’s sex and age. The following hypotheses were tested:

  1. 1)

    Migration background should be negatively associated with the different facets of the HLE and with children’s language abilities, but positively associated with TE. Consequently, children without a migration background should live in a greater quality HLE, show greater German linguistic abilities, and experience lower TE compared to children with a migration background. Further, TE should be negatively associated with linguistic abilities.

  2. 2)

    In addition, based on Bronfenbrenner’s ecological model (1979), the four different facets of the HLE might act as mediators between migration background and linguistic abilities, even when controlling for family SES and children’s age and sex.

  3. 3)

    Finally, a mediation effect of TE between migration background and linguistic abilities was expected, even when controlling for family SES and children’s age and sex.

Figure 1 shows the expected associations between family migration background and children’s linguistic abilities, mediated by various facets of the HLE and TE.

Fig. 1
figure 1

Presentation of the hypotheses. Note: HLE = Home Literacy Environment

Method

Sample

Data assessment took place within the context of a large-scale longitudinal study in Germany (Project “Learning4Kids”; please refer to Niklas, Annac, & Wirth, 2020) and was approved by the ethics committee of the University of Munich. Here, 190 preschool children (48.4% male and 51.6% female) and their families participated in the study and parental consent was obtained. The children were between 51 and 75 months old (Mage = 63.58, SDage = 4.42).

Data collection

The sample was recruited in kindergartens of a large city in South Germany. Here, kindergarten directors were informed about the project, and forwarded the provided information to the parents. All child assessments were conducted by trained research assistants and took place in the families’ homes on one day between mid-June and early August 2020. The visits lasted approximately 2.5 hours and comprised assessments of child abilities, while the parents were asked to fill-in a survey. More detailed information on the project and all test procedures can be found in Niklas, Annac, and Wirth (2020).

Test instruments

Parental survey

A parental survey (see online supplemental material 1) was used to assess family background characteristics as well as children’s TE and the facets of the HLE. The survey was translated into the most common spoken foreign languages in Germany (e.g., English, Turkish, Arabic, Russian, Vietnamese, etc.).

Socioeconomical status

An index of the SES was developed comprising parents’ highest educational qualification, highest prestige of the parental occupation and net household income (Wegener, 1988). The Magnitude-Prestige Scale is based on the 283 categories of the international standard classification of occupations (ISCO) according to “prestige”, that is, how much people with these occupations are respected in our society today. A power transformation is used to normalize this scale so that the lowest value is 20 and the highest 186.8. The prestige scale ranged in our sample from 22.4 (unskilled labourer) to 186.8 (physician). On average, the highest prestige score in a family from this sample was 92.78 (SD = 36.13), which indicates an above average SES compared with other German samples (see Niklas et al., 2020; Novita et al., 2022). More than half of the parents had a university degree or a higher qualification (57.4%, n = 109). About half of the families earned 3,419€ or more per month. Only 3.7% of families (n = 7) reported a net household income of “780€ or less”. The three indicators were z-transformed and averaged.

Migration background

Children were considered to have a migration background, when German was not exclusively the family language. In total, 41% of the families in the sample (n = 76) had a migration background. Within the families with a migration background, 13.3% spoke mostly German in the family, 42.7% spoke German and another language, and 44.0% spoke mostly another language (e.g., Turkish (n = 9), English (n = 6), Kurdish (n = 6), Romanian (n = 6), Arabic (n = 5), Vietnamese (n = 3), Albanian (n = 3), Italian (n = 3), Russian (n = 3) and other (n = 2) such as Bosnian, Bulgarian, Spanish, Greek, Uzbek, French, Thai). In addition, 22 languages were spoken by just one individual family in our sample.

Television exposure

TE was assessed as a sum score index comprising three items. The first two items measured TE during (a) a usual workday and (b) a usual day on the weekend (“how many hours does your child watch movies, videoclips, series on television (TV) or on the PC / laptop / tablet?”). Response options ranged from 4 = “more than 3 hours”, to 3 = “2–3 hours”, 2 = “1–2 hours”, 1 = “30–60 min”, and 0 = “less often/never”. The third item assessed whether the TV is “usually on when you are home, or do you turn it on only for certain shows/times?”. The response scale ranged from 2 = “TV is usually on”, to 1 = “TV is only on at certain times”, to 0 = “we/our children do not watch TV”.

Shared reading at home

Five items were used to assess reading at home. First, parents were surveyed about the onset of shared reading with their child. Second, parents were asked, how often they currently read to their child. Response options ranged from 4 = “several times a day”, to 3 = “daily”, to 2 = “several times a week”, and 1 = “once a week” to 0 = “less often/never”. The same scale was used for the third item: “Does your child look at picture books by himself/herself?”. Finally, parent-child shared reading (in minutes) was reported on a working day as well as on a Saturday or Sunday. Both, the onset of shared reading and parental reading were transformed into a Likert-scale. Here, the answers were assigned values of 0 through 4 with higher values indicating an earlier onset and longer shared reading times. All items were added up to a sum score.

Number of books

First, parents were asked to indicate the number of books in their household (all print media in all languages included, but no e-books). Response options ranged from 6 = “more than 200 books”, to 5 = “151–200”, 4 = “101–150”, 3 = “51–100” and 2 = “11–50”, to 1 = “1–10” and 0 = “none”. Second, parents indicated the number of children’s books and picture books they own. Response options ranged from 6 = “more than 100 books”, to 5 = “51–100”, 4 = “21–50”, 3 = “11–20”, 2 = “6–10” to 1 = “1–5” and 0 = “none”. Both items were combined in a mean score as indicator for books in the family’s household.

Knowledge about children’s books

Parents were asked to indicate which of 30 titles of children books were familiar to their child, using a German book title recognition test for children’s books (TRT-V; Grolig et al., 2017). The list of books was compiled with attention to the recency and representativeness of the books. The test also included ten fake book titles and parents were informed about this to avoid social desirability and guessing tendencies (Grolig et al., 2017). The difference between hit rate (ratio of correct books chosen) and false hit rate (ratio of fake titles chosen) is the final score, that we used in our study.

Parental attitude towards literacy

Parents were asked how much they agreed with the following four statements: “We like reading in our family”, “In our family, we often talk about things we’ve read”, “My child is very interested in being read to and is looking forward to it” and “Reading is an important activity in our family”. Response options ranged from 4 = “very strongly”, 3 = “strongly”, to 2 = “slightly”, 1 = “to a lesser extend” to 0 = “not at all”. The four items were combined in a mean score.

Measure of the linguistic abilities

Children’s linguistic abilities were assessed with an extensive battery of standardized tests in German, as it is the instructional and formal language in kindergartens and schools the children are exposed to (see Table 1 for an overview and Cronbach’s alpha). For each correct answer, children scored one point, whereas incorrect answers received zero point.

Active and passive vocabulary

To assess the active vocabulary, 15 items from the “Aktiver Wortschatztest für 3- bis 5-jährige Kinder- Revision” (AWST-R; Kiese-Himmel, 2005) were used. Children were required to name 15 picture cards, a total of four verbs (e.g., “throw”) and 11 nouns (e.g., “deer”). Nine sets (12 items per set) from the German version of the Peabody Picture Vocabulary Test (PPVT; Lenhard et al., 2015) were used to assess passive vocabulary. To ensure that the children understood the task, two sample items were presented first, and feedback was given to the children. After that, no further feedback was provided. For this test, children were presented with four pictures and they had to point to the correct picture (e.g., “Point with your finger to lab technician”).

Phonological awareness

Two subtests of the Würzburg Preschool Test (WVT; Endlich et al., 2017) measuring PA were applied. The first one was a rhyming task with eight items. After two example items with feedback, the test started without further support. Children had to decide which of the four given words that were also shown on pictures did not rhyme (e.g., “Igel-Hai-Geweih-Ei”). The second one was an initial phoneme identification task with eight items. Children were asked to identify and name the first sound and the remaining word (e.g., “Frosch” and “Fffff…rosch” as answer).

Receptive and productive letter knowledge

Both receptive and productive letter knowledge were examined with subtests of the WVT (Endlich et al., 2017) and were assessed with 10 items each. In the receptive test, the children had to identify the correct letter among four letters presented to them (e.g., U-O-I-V. Can you show me /O/?). In the productive letter knowledge test, the children had to actively name letters (e.g., What is the name of this letter? /t/ as answer).

The six standardized subtests were combined into a children’s linguistic abilities scale. For this purpose, the six subtests were z-standardized and averaged.

Table 1 shows the descriptive statistics and reliability of all study variables and constructs.

Table 1 Descriptive statistics for all study variables (sample size, means, standard deviations, observed minima and maxima, and internal consistency (Cronbach’s α))

Analysis overview

Data analyses were conducted using SPSS 24 (IBM, 2016). Descriptive statistics and correlational analyses will be presented first. Next, five mediation analyses were conducted using the PROCESS macro for SPSS (Hayes, 2017) to test whether the facets of HLE and TE served as mediators between migration background and linguistic abilities in the sample, while controlling for family SES and children’s sex and age as covariates.

Results

Descriptive statistics and correlational analyses

Table 2 presents the results of the correlational analyses of the facets of the HLE and TE with migration background, the linguistic abilities and control variables.

Table 2 Cross-sectional correlational analysis

The four facets of the HLE were positively intercorrelated and also positively associated with children’s linguistic abilities. In addition, children with a migration background lived in a lower quality HLE and showed weaker linguistic abilities than children without a migration background. As expected, migration background was positively associated with TE which, in turn, was negatively associated with all facets of the HLE and children’s linguistic abilities. No significant associations between the facets of the HLE, children’s TE, and children’s linguistic abilities with children’s age and sex were found with the exception of a small but significant correlation between children’s age and parental attitudes. However, children with a migration background had a lower SES and watched more television than children without a migration background. In contrast, children with a high SES lived in a higher quality HLE and showed better linguistic abilities.

Testing the mediation hypotheses

To further investigate the association between migration background and children’s linguistic abilities, five mediation analyses were conducted using the four facets of the HLE and TE as mediators. Here, migration background was entered as the predictor for children’s linguistic abilities. Standardized coefficients for the total and direct effects are presented in Fig. 2.

Figure 2 shows the associations between migration background and children’s linguistic abilities, separately mediated by the four facets of the HLE and TE, while controlling for children’s age and sex and family SES. Significant standardized indirect effects of migration background on children’s linguistic abilities mediated by reading at home with an effect size of − 0.21 (confidence interval (C.I.) [− 0.37, − 0.08]), by the numbers of books with an effect size of − 0.21 (C.I. [− 0.36, − 0.08]), by the children book title recognition task with an effect size of − 0.43 (C.I. [− 0.68, − 0.25]), and by parental attitudes towards literacy with an effect size of − 0.12 (C.I. [− 0.26, − 0.02]) were found.

Fig. 2
figure 2

Overview of the associations between migration background and children’s linguistic abilities, separately mediated by reading at home, number of books, knowledge about children’s books (KCB), parental attitudes towards literacy and television exposure (TE). Note: Standardized beta coefficients. All analyses are controlled for family SES and children’s age and sex. R2 represents the determination coefficient of every mediation model in this order: reading at home, number of books, knowledge about children´s books, parental attitudes, and television exposure. aTotal effects (migration background as only predictor of children’s linguistic abilities). bDirect effects (effects of migration background on children’s linguistic abilities when HLE and TE are separately included as mediators). *p < .05 **p < .001.

Similarly, a mediation effect was found for TE. The indirect effect size of migration background on children’s linguistic abilities mediated by television exposure was − 0.14 (C.I. [− 0.27, − 0.05]).

In all mediation analyses, migration background was no longer a significant predictor of children’s linguistic competencies, after any one of the mediators was entered in the model. Consequently, the four facets of the HLE and TE fully mediated this association.

Discussion

Although research has focussed on the HLE and children’s linguistic abilities for decades, little is known about migration background and its relationship with TE, individual facets of the HLE and child linguistic outcomes. Early linguistic abilities are essential for academic success and later career. However, children with a migration background often show difficulties when acquiring the language of instruction in formal settings. The purpose of this study was to examine whether TE, four different facets of the HLE, and migration background were associated with children’s linguistic abilities and specifically, whether and to which extent these different HLE facets and TE act as mediators between migration background and children’s linguistic abilities while controlling for family SES and children’s age and sex. The main results indicate that migration background is not directly associated with children’s linguistic abilities, but indirectly via TE and different facets of the HLE (see also Niklas et al., 2013a, b; Schmiedeler et al., 2014).

The four facets of the HLE were moderately to strongly positively related with each other and to children’s early linguistic abilities. Similar findings have been reported by previous studies (Burgess et al., 2002; Egan et al., 2022; Lambrecht et al., 2019; Niklas et al., 2016; Rose et al., 2018). As expected, children with a migration background showed weaker linguistic abilities. This finding aligns with other studies indicating that, at least in Germany, children with a migration background often have language development deficits in one or both languages and display poor language skills in vocabulary and PA (Dubowy et al., 2008; Eisenwort et al., 2018; Niklas et al., 2011; Novita et al., 2022). In addition, children with a migration background lived in lower quality HLEs (see also McElvany et al., 2009; Niklas et al., 2016; Novita & Kluczniok, 2022). These families owned fewer books, had less knowledge about German children’s books, showed a less frequent shared reading behaviour, and deemed shared reading as less important compared to families without a migration background. In comparison, in these families, more time was spent watching television (MTE−MB = 1.71, SDTE−MB = 0.85; MTE−noMB = 1.02, SDTE−noMB = 0.56).

The results further indicate that TE competes with HLE. Similar to other studies, TE was negatively associated with HLE, specially with the number of books, with SES, and with early linguistic abilities (Madigan et al., 2020; Niklas et al., 2013a, b; Schmiedeler et al., 2014), but TE was positively associated with migration background. The prediction of early linguistic abilities by migration background became no longer significant, once TE was considered.

Liebeskind et al. (2014) showed that the number of books was associated with verbal parent-child interactions, which was also linked to better language skills. The authors argued that a large book collection provides space for language enhancing conversations and interactions. Children’s storybooks also contain more complex vocabulary compared to everyday conversations and therewith support children’s language acquisition (Sulzby, 1985). In addition, the number of books is positively related to parental support of children’s learning to read (Burgess et al., 2002).

Similarly, in the mediation analyses, migration background did not predict early linguistic abilities directly any longer when the four facets of the HLE were considered as mediators and SES was controlled for. Consequently, the association between migration background and children’s early linguistic abilities was explained by the HLE mediators, indicating that not the migration background itself, but rather the associated parent-child-interactions and family characteristics play an important role for children’s linguistic abilities (see also Niklas, 2015). This finding aligns with OECD reports (2020) showing that migration background is not associated with child competencies in some countries.

Given that a high quality HLE is associated with better child outcomes, the HLE and TE clearly are good targets for family interventions (e.g., Baralt et al., 2022; Mol et al., 2008; Niklas & Schneider, 2017; Niklas et al., 2020). Here, various facets of the HLE that were closely associated were identified, but still distinct from each other and could all be the target of such interventions.

Limitations

Several limitations of this study should be considered. All data are cross-sectional, and the results need to be interpreted cautiously as no causality can be inferred. All the variables with the exception of children’s linguistic abilities were assessed via parental questionnaires, which may be prone to social-desirability bias, misinterpretation or misreporting of the information (Ziegler & Buehner, 2009). However, previous studies on HLE showed that questionnaires often provide reliable data which is in accordance with other measures (Burgess, 2002). In addition, a children’s book title checklist that included fake titles was used, which should be less prone to social-desirability answering (Grolig et al., 2017). Despite the fact that the sample included a diversity of migration backgrounds, different cultural backgrounds could lead to divergent results. A more sociological approach may help to understand how cultural backgrounds are related to different home learning environments and activities as well as TE.

Another issue for consideration is the moderate to strong correlations between the facets of the HLE, which partly indicate multicollinearity. For example, the number of books may exert an indirect effect on children’s linguistic abilities via shared reading. These results highlight the potential need to restructure the concept of the HLE, grouping together facets that had been considered independent or highlighting the interdependence between them (Wirth et al., 2023). Further, we explicitly excluded e-books from the analyses, as research indicates different pathways for an analogue and a digital HLE (Lehrl et al., 2021). Future research needs to analyse the role of e-book reading and the digital HLE for children’s literacy development. In an exploratory approach, we used path analyses to include all variables in a model simultaneously. In such a model, migration background was still significantly associated with all mediators, but did not predict child outcomes directly. Concerning the mediators, the number of books was the only significant predictor of linguistic abilities (p < .05), with the knowledge of children’s books showing a tendency to predict these abilities (p < .10).

Our measure of the knowledge of children´s books (KCB) focused on German book titles only and this result must be cautiously interpreted as non-German-speaking parents might read these and other books to their children in their mother tongue and may thus have a greater knowledge on other books that are more common in their country of origin. Nevertheless, our findings emphasize the fact that children with a migration background in Germany are generally less frequently read to compared to children without a migration background, which may be reflected in their lesser KCB.

The measure of TE focussed on the amount of time watching television and on background television, but not on other digital media. Consequently, a more comprehensive assessment of quantity of screen time could have led to different results. Moreover, potential changes in both HLE and TE could not be analysed. In fact, Ennemoser and Schneider (2007) suggest that television exposure depends on the seasons with greater TE in winter compared to summer and the assessments took place in summer, which may have impacted on the results. In addition, we did not assess in which language children watched television. Children with a migration background might benefit from watching television in German, as it increases their exposure to the German language. For example, Kahn-Horwitz and Saba (2018) argue that watching television in another language may improve children´s reading skills due to the use of subtitles. However, it remains unclear whether this finding can be applied to preschool age, because most preschool children do not have strong reading skills and as, in Germany, television is broadcasted without subtitles. Moreover, a high TE, which is more typical for families with a migration background in Germany (Leyendecker et al., 2014), is more likely to result in reduced parent-children’s interactions (Madigan et al., 2020) and thus may be detrimental for the acquisition of linguistic abilities.

On the other hand, the Corona pandemic as context of this study should be considered. As the kindergartens were closed for some months and social contacts were limited, TE and parent-child-interactions at home may have increased during the months prior to the assessments (Lehrl et al., 2021). Consequently, the results presented should be interpreted cautiously, although they are in line with previous studies (Eisenwort et al., 2018; Ennemoser & Schneider, 2007).

The quantity but not the quality of TE was examined in the study. Children’s engagement with digital media is more complex than measuring TE. For example, the purpose of watching a particular television program may be important, considering the potential educational value of television (Anderson et al., 2001; Mares & Pan, 2013). In addition, moderating factors such as joint media usage may lead to different findings (Dore et al., 2020a).

Strengths

Despite these limitations, this study has also several strengths. This study has practical implications for policy and families, especially for families with a migration background. Based on these findings, interventions can be developed to foster parent awareness towards the importance of the HLE and the potential negative consequences of a high TE (e.g. Niklas et al., 2020). For instance, such interventions may target parents’ attitudes towards shared reading with and screen time of young children. Another possibility would be to provide parents with appropriate reading material such as children’s books for free, which has proven to enhance both, the HLE and children’s literacy-related skills, at least in early years (De Bondt et al., 2020). Clearly, the implementation of programmes that promote parental involvement enrich the HLE with regard to children’s linguistic development (e.g., Baralt et al., 2022; Niklas & Schneider, 2017). The Chancenreich program in Germany shows positive longitudinal effects of the family support program on parental involvement and vocabulary acquisition of preschool children (Cohen et al., 2020). Consequently, these programs which offer parenting-skill and parent-child-interaction courses might be a great support for families with a migration background. Promoting specific programs for families with a migration background which emphasize the potentially detrimental effects of TE and positive effects of a high-quality HLE may lead to a better understanding of children’s development and thus help parents to provide their children a better home learning environment.

Further, the family environment was assessed, considering not only the SES but also migration background, which is not very common in research on HLE (Niklas et al., 2013; Novita & Kluczniok, 2022). In addition, in this study, migration background was operationalised via family language, which is not common in the HLE research, but nevertheless resulted in findings consistent with other studies (Niklas et al., 2020; Rose et al., 2018; Whitehurst & Lonigan, 1998). Consequently, not only ethnicity is related to other study variables, but also family language (Novita et al., 2022).

For the analysis, a comprehensive index of family SES was controlled in order to avoid a confounding relationship between migration background and children’s linguistic abilities. The results indicate that migration background plays an indirect role only in children’s linguistic abilities via HLE and TE (see also Eisenwort et al., 2018; Niklas et al., 2013a, b). The findings suggest that a high quality HLE, in which children are frequently read to, may influence children’s linguistic abilities more directly, while migration background seems to play a secondary role.

This paper sheds light into the controversial findings about TE, migration background, and children’s linguistic abilities. Although no causal statements can be inferred, the results show that TE was negatively related to linguistic abilities and positively related to migration background. The mediating role of TE offers the opportunity to raise awareness among families with and without migration background of potentially detrimental effects of excessive TE at an early age.

Based on the finding that all four facets of the HLE and TE acted as mediators between migration background and children’s literacy abilities, researchers may decide which aspect to assess depending on their own research focus.

Conclusions

This study shows that various facets of the HLE provided by families and the TE of children play an important role in their linguistic development. The four facets of the HLE and TE mediated the relationship between migration background and children’s early linguistic abilities, when the family SES, children’s sex and age were controlled for. In the sample, families with a migration background provided a less favourable HLE than families with German as the main language spoken at home. Further, TE was greater for children with a migration background.

Compared to family background variables such as SES and migration background that are more static and difficult to modify, the quality of the HLE and the TE can be changed more easily in order to support children in the development of their linguistic abilities. An understanding of the vital benefits of parent-child interactions and the detrimental role TE may play is important for developing interventions, and to raise awareness among families with a migration background. Although the cross-sectional analyses need to be interpreted with caution, these findings contribute to a better understanding of the association between family background variables, the HLE, TE, and children’s linguistic outcomes.