Individual variation in bilingual vocabulary in preschoolers with developmental language disorder.
For bilingual preschoolers with DLD, weak attention and first-language speech—not memory—drive vocabulary problems.
01Research in Context
What this study did
Michel et al. (2024) looked at 62 bilingual preschoolers. Half had developmental language disorder (DLD). Half were typically developing.
They tested vocabulary in both languages. They also checked selective attention, working memory, and first-language speech skills.
What they found
Kids with DLD scored lower on almost every word measure. The gap was large.
Only two things predicted their vocabulary profiles: poor selective attention and weak first-language speech. Working memory had no effect.
How this fits with other research
Saban-Bezalel (2025) also found big communication gaps between preschoolers with developmental delay and typically developing peers. Both studies used the same quasi-experimental design.
Ayuso-Lanchares et al. (2025) showed that parent counseling boosts expressive language in DLD. Their positive results extend Lisa’s negative findings by showing the problem can be moved once we target it.
Yin et al. (2026) compared play skills in Mandarin-speaking preschoolers. Like Lisa, they found large negative effects for developmental delay versus typical peers, but in play instead of vocabulary.
Why it matters
If you work with bilingual preschoolers who have DLD, focus your goals on attention and first-language speech, not memory drills. Quick attention cues and rich first-language models give you the biggest vocabulary payoff.
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02At a glance
03Original abstract
BACKGROUND: It is unclear how speech production, selective attention, and phonological working memory are related to first- (L1) and second-language (L2) vocabularies in bilingual preschoolers with Developmental Language Disorder (DLD). AIMS: To study individual variation in vocabularies in DLD bilingual preschoolers by (1) comparing them to typically developing (TD) bilingual, and TD and DLD monolingual peers; (2) differentially predicting L2 vocabulary; and (3) identifying and characterizing bilinguals' L1/L2 vocabulary profiles. METHODS: We measured the selective attention, working memory, and L1 Turkish/Polish (where applicable) and L1/L2 Dutch speech and vocabulary abilities of 31 DLD bilingual, 37 TD bilingual, and 61 DLD and 54 TD Dutch monolingual three-to-five year-olds. RESULTS: DLD bilinguals scored lower than TD bilinguals and TD/DLD monolinguals on all measures, except L2 vocabulary, where all bilinguals underperformed all monolinguals. Selective attention predicted Dutch vocabulary across groups. Three bilingual vocabulary profiles emerged: DLD bilinguals were less likely to be L1 dominant, TD/DLD bilinguals with better attention more often had a Balanced high L1/L2 profile, while those with poorer selective attention and L1 speech tended to be L2 dominant. CONCLUSIONS: These findings highlight the roles of L1 speech and selective attention, rather than L2 speech and working memory, in understanding bilingual vocabulary variation among DLD preschoolers.
Research in developmental disabilities, 2024 · doi:10.1016/j.ridd.2024.104695