Language development is often one of the most discussed topics among others of child development. Children typically begin to babble between the age of 6 months and 9 months; then followed by a phase called “name explosion” or “word spurt” around 18 months, in which they learn vocabulary rapidly (Hibel, 2018). Simultaneously from 12 to 18 months, children start producing holophrases: expressing their needs, desires, and/or thinking in a single word (San Souci, 2018b). Of course, not every child will follow the same exact path, nor will they have any of the phases above. Impairment in the brain’s language areas or other parts of the brain cortex can lead to delay in language acquisition (San Souci, 2018c). Despite biological impairments, environmental factors can also have an impact on a child’s process of acquiring a language, that include the socio-economic status (SES) of the family, symbolic or pretend play, and parent-child interaction.
Families from a lower SES may have a much more difficult time providing a child’s needs during their development compared to families from a higher SES (“Children, Youth,” n.d.). The lack of necessities during development may in turn affect language development in children. Consequently, Saha et al. (2009) examined how household food security (HHFS) could affect early language development of 1639 18-month-old infants from rural Bangladesh. Some data were collected before the infants were born; and some were collected throughout their development. Then by 18-month-old, infants’ language development was assessed with the MacArthur’s Communicative Development Inventory, in which the mothers had to report how well their children have mastered the understanding and communication of words from various groups. According to the data collected, Saha et al. (2009) concluded that HHFS was positively linked to these rural Bangladesh infants’ early language development. The lower HHFS the less understanding and communication the 18-month-old infants would have on words from various categories. The researchers suggested two ways that HHFS could affect these infants’ language development: infant-feeding practices, and maternal stress. Saha et al. (2009) thought that good infant-feeding practices could lead to better early language development since the children would get their required nutrients. While maternal stress could lead to improper infant-feeding practices; therefore, the development of children was negatively impacted as well as their language acquisition. This means if children came from families that are struggling for daily needs, they might require additional resources or support to catch up to their peers from a higher SES family.
In contrast, another study assessed a different aspect of SES have on children’s early language acquisition. Letts et al. (2012) conducted a study on how maternal education and postcode-related indicators of SES have an effect on children’s performance on the New Reynell Development Language Scales (NRDLS). A total of 1266 children between exactly 2 to 8-year-old, who completed the NRDLS were recruited from various regions of England. Their scores from both Comprehension and Production Scales were compared and separated into four groups based on maternal education: Statutory years only, Further education, Higher Education, and Postgraduate qualifications. Rank of Index of Multiple Deprivation (IMD) was also to determine the families’ SES. The results suggested that the children from lower SES background did have a lower performance than the children from higher SES background. Yet, the relationship between maternal education and children’s performance on Comprehension was complicated. An extreme effect was found between the Statutory years only and Postgraduate qualifications, but the Comprehension performance between Further education and Higher education was similar. Therefore, even with Production scores showing a significant effect between Statutory years only and the other three groups, maternal education might not be a reliable indicator of SES and SES in this study did not have a significant influence on these children. This also means that certain aspects of SES might have a bigger effect on language acquisition than others with the different results from the two studies.
In addition to SES, symbolic or pretend play also plays a role. Symbolic or pretend play occurs when children begin to use object substitution in play, for instance, substituting a banana for a phone. (San Souci, 2018c). This typically emerges from toddlerhood and continues through pre-school. (Hibel, 2018). It is not only a big part of social interaction, but also in language acquisition, especially verbal language acquisition. (San Souci, 2018c). Hall et al. (2013) had studied how play and gestures interact with the verbal language development of children from 18 to 31-month-old. A total of 50 children were recruited from Melbourne, Australia. The researchers relied on the Test of Pretend Play, and the Word Games Vocabulary to measure the children’s symbolic play and gestures. These children’s language development was also assessed by the MacArthur Communicative Development Inventory. Based on their findings, a positive correlation was found between symbolic play and gesture use, while gesture use was more strongly correlated with verbal language acquisition than symbolic play. This led to Hall et al. (2013) believe that children’s development of verbal language acquisition could emerge from action-based schema and joint activity, in which language is associated with actions during children’s symbolic play and through playing children learn those actions. Therefore, symbolic play highly facilitates children’s learning in spoken language. This study demonstrates an important aspect that some factors might seem less critical, yet, they are still needed for development just like symbolic play and gesture use together aid children’s language development.
Furthermore, Smith and Jones (2011) suggested that symbolic play may link to language learning through visual object recognition. Sixty-three children from the age of 18 to 27 months were recruited to the study. Each of them was presented with an object recognition task and 3 sets of symbolic play task. Both tasks contain rich and sparse objects, in which the rich represents realistic toy of the objects and sparse represents geometric shape of the objects; while the rich objects in the symbolic play were indication of the themes and the sparse objects were used to measure children’s understanding of the symbolic situation. Most children could recognize and name the objects when presented with rich objects, but when presented with the sparse objects, it was harder for some to recognize and name the objects. Similarly, for the rich object themed plays children did show understanding of the task; yet, there were variations in children’s understanding for the sparse object themed plays. Smith and Jones (2011) realized that there was a strong correlation between the sparse object recognition task and the use of sparse object in symbolic play. This revealed that children’s ability to recognize a sparse object may affect their ability in substituting a sparse object for a themed play, in turn affect their early language learning as they could not understand the names of the objects. Therefore, rich objects might allow children have a better understanding of the objects around their environment in order for them to learn names. It is also an indication that there could be problems in children’s language development if they are unable to identify or name the sparse objects at certain ages.
Another important factor for language acquisition is parent-child interaction. Zimmerman et al. (2008) tested the different effects of adult language input, television viewing, and adult-child conversations have on language acquisition with 275 families who have children from 2 to 48-month-old. All families were in phase 1 that studied how home language environment affect children’s language development for 6 months, and 71 were part of phase 2 in which they had an 18 months long assessment. Children’s language ability was assessed with the Pre-school Language Scale (PLS-4) throughout the study. Data suggested that both adult-language input and adult-child conversations were positively associated with children’s performance on PLS-4 and television viewing was negatively associated with children’s performance on PLS-4. When Zimmerman et al. combined the data of the three predictors, they recognized that adult-child conversations had a much more significant impact on children’s early language development than adult-language input. This implies that adult-child conversations might indeed promote early language acquisition in children. In addition, it demonstrates that children cannot learn from listening to audio alone: they need interaction.
DeLoache et al. (2010) was also interested in whether or not babies actually learn from media. Seventy-two children from the age of 12 to 18 months were recruited and randomly assigned to the four conditions: video-with-interaction, video-with-no-interaction, parent-teaching, and control. All children’s language capacity was pre-assessed, and a target range of vocabulary was tailored to the children to see how much they learn. According to the data, children from the video-with-interaction or no interaction conditions learned less new words than the children from parent-teaching group. This study illustrates that adult-child interaction is critical for early language development. Moreover, one-on-one live interaction allow children to learn new words along the conversation and learn language within their social context.
In conclusion, environmental factors are also essential in early childhood language development. The studies of Letts’ et al. (2012) and Saha et al. (2009) suggested that different parts of SES may have more compelling effects on a group’s early language development than the others. While Hall et al. (2013) and Smith and Jones (2011) recognized that symbolic play help children with language learning through complex interactions, including object substitution and recognition. Their studies also point out that even within a domain, there are smaller factors that create the bigger picture. Further, adult-child conversations and teaching facilitate are essential for children’s early language acquisition in a social setting as implied by Zimmerman et al.’s (2008) and DeLoache et al. (2010). Early language acquisition depends immensely on the amount of environmental stimulations a child gets, and it will continuously affect their development throughout childhood.