Abstract
Background: Among twins, lower linguistic skills emerged when compared with singletons. Considering the association found between parental linguistic input and children's language development, exploring the differences between twins and singletons' linguistic environments could find variables that are potentially associated with the lower linguistic skills of twins.Aim: The current systematic review aims to analyze and systematize the existing literature focused on the comparison of twins' and singletons' linguistic environments within their first 3 years of life. Methodological issues (i.e., the procedure used to assess the linguistic environment, the coding of the linguistic environment's features, the computational method employed to assess the parental linguistic input, and participant characteristics) and differences found among twins and singletons regarding their linguistic environment (i.e., linguistic input quantity, linguistic input complexity, linguistic features of child-directed speech, parental responsiveness, and directiveness, joint attention, and book reading) were highlighted.Method: The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement was followed. Eligible studies were searched through EBSCO, PubMed, and Web of Science. From this search, 1,347 study results emerged, and 8 studies were included.Results: To our knowledge, this is the first systematic review focused on the comparison of twins' and singletons' linguistic environments. Differences between the groups were found in all of the included studies. Data against twins were generally identified regarding all the considered linguistic environment's features. However, conflicting results within and between the included studies emerged, mainly according to the computational method employed (i.e., twin moms value, twin direct dyadic value, twin direct dyadic + both value, and input directed toward both children simultaneously).Conclusion: The disadvantaged linguistic environment of twins is likely due to limited parental resources and demands associated with the management of two children of the same age. However, the limited and conflicting data found did not allow for a firm conclusion to be drawn on the differences in the twins' and singletons' linguistic environments. Further studies on the topic are needed.
Highlights
Several studies found significant differences between twins and singletons regarding their linguistic development (Özçakar et al, 2003; Rutter et al, 2003; Olivennes et al, 2005; Nan et al, 2013; Rice et al, 2014; D’haeseleer et al, 2016)
We identify the differences between the studies included regarding the procedure used to assess the linguistic environment, the coded linguistic environment’s features, the computational method employed to assess the parental linguistic input, and the characteristics of the groups included as participants
The methodological issues identified within the studies are explored to review the following: the procedure used to assess the linguistic environment, the coded linguistic environment’s features, the computational method employed to assess the parental linguistic input, and the characteristics of the groups included as participants
Summary
Several studies found significant differences between twins and singletons regarding their linguistic development (Özçakar et al, 2003; Rutter et al, 2003; Olivennes et al, 2005; Nan et al, 2013; Rice et al, 2014; D’haeseleer et al, 2016). Controlling for potential confounding variables (i.e., age, gender, social background, prematurity), lower language scores among twins were identified. Nan et al (2013) identified lower scores on communication among twins at ages 3, 6, and 9 months, controlling for prematurity and gender. A recent study confirmed these findings, identifying lower receptive, and expressive linguistic skills among twins compared with singletons matched for age and gender. Controlling for birthweight, Dezoete and MacArthur (1996) did not find differences among twins and singletons regarding quality of language and intelligibility of speech From their perspective, the lower scores that emerged in other studies could be influenced by the overrepresentation within twins’ groups of children of low birthweight, a condition which represents about 60% of twin births (Martin et al, 2015). Considering the association found between parental linguistic input and children’s language development, exploring the differences between twins and singletons’ linguistic environments could find variables that are potentially associated with the lower linguistic skills of twins
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
