Language profiles in children with Down syndrome and children with language impairment: implications for early intervention.
Down syndrome language is delayed but structurally typical, whereas language impairment shows a distinct grammar deficit—match your intervention targets accordingly.
01Research in Context
What this study did
Polišenská et al. (2014) compared language skills in preschoolers with Down syndrome and children with language impairment.
They used standard tests to look at vocabulary size, sentence length, and grammar errors.
The goal was to see if each group shows a unique language pattern that could guide therapy choices.
What they found
Kids with Down syndrome had smaller vocabularies and shorter sentences, but the shape of their grammar looked like younger typical kids.
Kids with language impairment had vocabularies that matched their age, yet they made odd grammar errors not seen in Down syndrome.
The two groups need different intervention targets: delay-style for Down syndrome, rule-teaching for language impairment.
How this fits with other research
Dudley et al. (2019) extends these findings by showing Down syndrome syntax stays flat until mental age reaches 7–9 years, so pushing complex grammar earlier is unlikely to work.
Amore et al. (2011) used a similar design and found Down syndrome preschoolers imitate body movements better than they talk; you can use this strength to model sentence frames during motor play.
Hatton et al. (2004) seems to contradict because parents of Down syndrome kids used longer sentences than expected, yet the kids still showed delayed grammar. The difference is parent input versus child output: parents talked more, but the children still followed a typical delay track, supporting Kamila’s view that grammar rules are intact yet slow.
Why it matters
Stop using the same language goals for every developmental diagnosis. If the child has Down syndrome, treat the profile like a slower version of typical development: boost vocabulary and mean length first, then add grammar once mental age nears school level. If the child has language impairment, target grammar rules directly even when vocabulary looks fine. Match the tool to the profile and you will waste fewer trials on the wrong skill.
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02At a glance
03Original abstract
This study investigated early language profiles in two groups of children with developmental disability: children with Down Syndrome (DS, n=13) and children with Language Impairment (LI, n=16). Vocabulary and grammatical skills in the two groups were assessed and compared to language skills of typically developing (TD) children matched on size of either their receptive or expressive vocabulary (n=58). The study aimed to establish if language development in these groups is delayed or fundamentally different than the TD groups, and if the group with DS showed a similar language profile to the group with LI. There is a clinical motivation to identify possible key risk characteristics that may distinguish children who are likely to have LI from the variation observed in TD children. Three clear findings emerged from the data. Firstly, both receptive and expressive vocabulary compositions did not significantly differ in the clinical groups (DS and LI) after being matched to the vocabulary size of TD children. This provides further support for the idea that word learning for the children in the clinical groups is delayed rather than deviant. Secondly, children with LI showed a significantly larger gap between expressive and receptive word knowledge, but children with DS showed a pattern comparable to TD children. Thirdly, children with LI who understood a similar number of words as the TD children still had significantly poorer grammatical skills, further underlining the dissociation between lexical and grammatical skills in children with LI. Grammatical skills of children with DS were commensurate with their lexical skills. The findings suggest that language intervention should be specifically tailored to etiology rather than focused on general communication strategies, particularly in children with LI.
Research in developmental disabilities, 2014 · doi:10.1016/j.ridd.2013.11.022