Assessment & Research

Developmental trajectories of structural and pragmatic language skills in school-aged children with Williams syndrome.

Van Den Heuvel et al. (2016) · Journal of intellectual disability research : JIDR 2016
★ The Verdict

Expressive vocabulary surges ahead in Williams syndrome, but receptive and pragmatic skills lag and stall—so test and teach each area separately.

✓ Read this if BCBAs doing language assessments with school-aged children with Williams syndrome.
✗ Skip if Practitioners who only serve adults or clients without genetic diagnoses.

01Research in Context

01

What this study did

Libero et al. (2016) tracked language growth in school-aged children with Williams syndrome. They compared expressive vocabulary, sentence understanding, and pragmatic skills against kids with other intellectual disabilities.

The team used a quasi-experimental design. They tested the same children more than once to map how each skill changed over time.

02

What they found

Expressive vocabulary grew faster in Williams syndrome than in the control group. Yet sentence comprehension stayed weak and pragmatic gaps widened as kids got older.

In short, talking words outpaced understanding words and using words socially.

03

How this fits with other research

Nevin et al. (2005) first showed that children with Williams syndrome outscore children with Down syndrome on vocabulary size. E et al. now show that this early edge keeps climbing, but only for expressive labels.

Grindle et al. (2012) found flat receptive language scores on the ITPA. E et al. extend that snapshot into a trajectory, proving that receptive deficits do not catch up.

Lallier et al. (2014) saw that adults with Williams syndrome still judge grammar like seven-year-olds. E et al. reveal when that plateau starts—during the school years—so you can target syntax earlier.

04

Why it matters

Do not let big vocabularies fool you. Keep separate goals for expressive labels, sentence comprehension, and pragmatics. Re-assess each domain on its own schedule, and start syntax intervention before the plateau seen in later studies.

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02At a glance

Intervention
not applicable
Design
quasi experimental
Sample size
24
Population
intellectual disability, other
Finding
mixed

03Original abstract

BACKGROUND: This study aimed to compare developmental courses of structural and pragmatic language skills in school-aged children with Williams syndrome (WS) and children with idiopathic intellectual disability (IID). Comparison of these language trajectories could highlight syndrome-specific developmental features. METHOD: Twelve monolingual Dutch-speaking children with WS aged 5.10 to 13.3 years were assessed by means of standardised structural language tests measuring receptive and expressive vocabulary and sentence comprehension and production. Pragmatic language was evaluated by means of an expressive referential communication task and a retelling test. All of these language abilities were re-evaluated with the same measures after a period of 18 to 24 months. Performance was compared to 12 children with IID pairwise matched for chronological age (CA) and non-verbal fluid reasoning (Gf) at Time 1. Non-verbal mental age (NVMA) was taken into account when delineating developmental trajectories. RESULTS: Children with WS outperformed children with IID on expressive vocabulary development. In contrast, sentence comprehension was significantly poorer than in children with IID at the second time point. Increased variability and rather poor performance on pragmatic language tasks were demonstrated in the WS group. Irrelevant and off-topic extraneous information transfer continued to be a syndrome-specific characteristic of children with WS. CONCLUSION: The data provide new insights into diverging developmental trajectories across language domains. Expressive structural language skills tend to progress more rapidly than receptive language skills in children with WS causing more distinctive language profiles over time. Some children with WS seem to benefit from the growth in expressive structural language abilities to enhance their expressive pragmatic language skills, while in some others these abilities remain challenging. This study highlights the need for continued follow-up of language challenges in WS and for a dynamic and individualised interventional approach.

Journal of intellectual disability research : JIDR, 2016 · doi:10.1111/jir.12329