Expressive and receptive vocabulary in children with Williams and Down syndromes.
Williams and Down syndromes produce opposite expressive-receptive splits, so assess and treat each domain separately.
01Research in Context
What this study did
Nevin et al. (2005) compared expressive and receptive vocabulary in children with Williams syndrome and Down syndrome. They ran a small case-series study. Each child completed the same word tasks so the teams could spot syndrome-specific error patterns.
What they found
Kids with Williams syndrome scored higher on most lexical tasks than kids with Down syndrome. The two groups also made different kinds of mistakes. The gap stayed even when overall mental age was similar.
How this fits with other research
Libero et al. (2016) followed the same Williams group across school years. Expressive vocabulary kept climbing, but sentence comprehension and pragmatic skills lagged behind. This extends the 2005 snapshot by showing the gap grows over time.
Grindle et al. (2012) gave the ITPA to Williams kids and found they still trailed both mental-age and chronological-age peers on every psycholinguistic subtest except visual reception. The result deepens the 2005 finding: the Williams advantage is narrow and tied to single-word tasks, not broad language skill.
Polišenská et al. (2014) looked at Down syndrome preschoolers and saw delayed but structurally typical language. López-Riobóo et al. (2019) saw the same pattern in young adults. Together they confirm Down language is simply late, while Williams language is different in shape, not just timing.
Why it matters
Do not assume mental age equals language age in either syndrome. For Williams, write separate goals for expressive vocabulary, sentence comprehension, and pragmatics. For Down, target vocabulary breadth and syntax but expect steady, typical progress. Pick assessment tools that split expressive and receptive scores so you catch the unique profile before you plan intervention.
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Join Free →Pull the last vocabulary report and check if expressive and receptive standard scores are more than one standard deviation apart; if they are, write distinct skill-tracking programs for each area.
02At a glance
03Original abstract
BACKGROUND: Williams (WS) and Down syndromes (DS) are two genetic disorders that involve intellectual disability (ID) and have been extensively studied over the past decades because of the unique linguistic profiles they exhibit. Recent investigations seek to explore the fractionation of linguistic components within the cognitive system using genetically based neurodevelopmental disorders such as WS and DS and to identify different profiles of linguistic function in these two groups of individuals. METHOD: The 'expressive vocabulary', 'receptive vocabulary', 'word opposites' and 'word definitions' subtests (Level 1) of the Test of Word Knowledge (TOWK) were used to assess lexical skills in six children with WS and five children with DS. RESULTS: Our findings indicate that the two syndromes exhibit substantial differences on linguistic tasks with individuals with WS performing at a higher level compared to those with DS and producing atypical responses in word definitions. The pattern of errors for each syndrome is qualitatively different suggesting that their underlying linguistic mechanisms are distinctive even though ID is similar. CONCLUSIONS: This study supports the differential outcome of two chromosomal disorders with similar ID. It also argues in favour of the large within group variability of the two syndromes that is not related to mental age but rather to different underlying mechanisms supporting language. These findings are discussed in the light of the current evidence concerning linguistic knowledge of neurodevelopmental and genetic disorders.
Journal of intellectual disability research : JIDR, 2005 · doi:10.1111/j.1365-2788.2005.00654.x