Are Early Life Language Experiences Key to SES-related Disadvantages?

• In Event: 3-237 - New Perspectives on Early Language Input, Learning Outcomes, and SES

Integrative Statement

The importance of language experiences in early life for children's linguistic, cognitive and scholastic development has a long been emphasized in the psychological literature. The narrative goes – simplified – like this: Children from disadvantaged family backgrounds experience impoverished language environments compared to children from families of higher socioeconomic status (SES). As a result of the difference in environmental provision, low SES children develop on average poorer language skills than their higher SES peers, and this gap in ability is noticeable already in infancy. Over time, the disadvantage in language affects the development in all other cognitive faculties, including school performance, because language is key to accessing and mastering relevant learning opportunities in general. As a consequence, children's SES-related differences in cognitive growth widen over time, with low SES children performing worse in school and eventually obtaining fewer educational qualifications than high SES children.
This narrative is not only intuitively plausible but also received support from numerous empirical studies. However, the vast majority of these studies suffered from low power, because they analyzed data from small samples and collected few observations, especially few naturalistic observations. To address this limitation, we present here data from two novel, well-powered investigations.
Our first study takes a close look at early life language experiences. We used digital language recorders (i.e. LENA system) to document the language environment that 107 toddlers aged 24 to 48 months experienced in their family homes. Families completed three full days of recordings, during which everything the target child heard and said was documented. This is to date largest naturalistic study of children's early life language experiences in the family home. Our analyses showed that toddlers' language experiences differed as much between as within families. This suggests that SES-related differences in language environments may be less pervasive for children cognitive development than previously assumed, because between-family differences are unstable.
Our second study focused on the long-term effects of children's differences in verbal ability. We used a sub-sample 661 children from the Twins Early Development Study (TEDS), who were assessed at age 4.5 years during researcher visits to the family home on a battery of overall 17 verbal and non-verbal ability tests. The sample was later also assessed on school grades in English and mathematics from age 7 through 16 years.
We found that SES correlated more strongly with children's verbal than non-verbal ability (r = .39 versus r = .26). In latent growth curve models, verbal and non-verbal ability predicted later grades in English and mathematics equally well. Also, verbal and non-verbal ability both mediated between 33% and 50% of the association between SES and school grades. These findings suggest that low SES children's disadvantage in school performance is associated with, but not exclusively driven by their poorer verbal skills.
Our studies, which are better powered than previous research, suggest that SES may be one of many systematic factors that inform children's early life language experiences, and that language skills are as important as non-verbal ability for school achievement. Overall, our finding challenge traditional narrative that surrounds early life language experiences.

Author

• Sophie von Stumm, The London School of Economics and Political Science
  Presenting Author