There has been some debate over the years around whether a language disorder should be distinguished from language disadvantage. The link between low socio-economic status (SES) and language difficulties is well established. In some deprived areas, as many as 50% of children do not have appropriate language skills for their age (Roy & Chiatt, 2013). This far exceeds the generally quoted prevalence rate of 7% across the population.
How can this be? The environments we grow up in strongly influence our own development, and it seems reasonable that poor linguistic input from parents could lead to language difficulties in their children. Indeed, one study found that pre-schoolers’ language patterns closely mirrored that of their parents, from the range of vocabulary they used, to their interaction styles (Roy and Chiatt, 2013).
This has led some to ask: if these children’s difficulties are down to their environments, rather than some innate difficulty with language learning, is it still appropriate to diagnose a language disorder? Could some of these children have the potential for normal language development, but have lacked the opportunity or language experience? And finally, are language difficulties caused by these kind of external factors different from those caused by internal ones?
Surprisingly, some patterns of difference have been observed. Some studies revealed that certain areas of language, such as vocabulary and multi-clausal sentences were more affected by SES than other areas, such as basic syntax (Roy and Chiatt, 2013). Other measures, such as non-word and sentence repetition, and use of grammatical inflections also appear to be less influenced by upbringing and are sometimes considered to be more reliable predictors of language disorder.
Some researchers have accounted for these differences by theorizing that certain aspects of language development may be more “in-built” than others. Basic syntax, and the non-word repetition tasks mentioned earlier may rely more on innate language processing abilities, and where there is no internal deficit, these skills may develop normally. On the other hand, building a rich vocabulary is a more knowledge-based endeavor, which relies on repeated exposure to a wide range of words in the environment.
Whatever the truth, in practice it is hard to differentiate between language difficulties caused by internal versus external factors, since risk factors tend to co-occur and interact. Social deprivation may lead to poorer language outcomes through the quality of language and interactions that children are exposed to in their environments. Or it may be due to heritable aspects which have been overlooked.
In 2016, a group of international experts concluded that there was no particular language profile associated with social disadvantage, and that the aforementioned trends are not an adequate basis on which to classify children (Bishop et al, 2017).
For more information on the causes of language disorders, please see my post:
https://secondaryschoolslt.wordpress.com/2026/01/05/what-causes-language-disorders/
Notes
Bishop DVM, Snowling MJ, Thompson PA, Greenhalgh T, CATALISE consortium (2016)
CATALISE: A Multinational and Multidisciplinary Delphi Consensus Study. Identifying Language Impairments in Children. PLoS ONE 11(7): e0158753.
Bishop, D.V.M., Snowling, M.J., Thompson, P.A., Greenhalgh, T., and the CATALISE-2 consortium (2017). Phase 2 of CATALISE: a multinational and multidisciplinary Delphi consensus study of problems with language development: Terminology. Journal of Child Psychology and Psychiatry, 58(10), pp. 1068–1080. doi:10.1111/jcpp.12721
Roy, P. and Chiat, S. (2013). Teasing apart disadvantage from disorder The case of poor language. In: Marshall, C. R. (Ed.), Current Issues in Developmental Disorders. Current Issues in Developmental Psychology. (pp. 125-150). PSYCHOLOGY PRESS. ISBN 9781848720848
Thoughts of a secondary school SLT 