Assessment & Research

Receptive vocabulary analysis in Down syndrome.

Loveall et al. (2016) · Research in developmental disabilities 2016
★ The Verdict

Down syndrome learners understand fewer verbs than nouns even when IQ is matched, so probe and teach verbs explicitly.

✓ Read this if BCBAs writing receptive language goals for school-age or adult clients with Down syndrome.
✗ Skip if Clinicians serving only ASD or fluency cases.

01Research in Context

01

What this study did

The team compared receptive vocabulary in three groups: Down syndrome, other intellectual disability, and typically developing peers.

They tested nouns, verbs, and describing words while holding nonverbal IQ and phonological memory constant.

All participants pointed to the correct picture after hearing a single spoken word.

02

What they found

The Down syndrome group understood fewer verbs than both other groups.

Nouns came easiest for Down syndrome and typical kids; the ID group scored the same on nouns and verbs but low on describing words.

Even after matching for IQ, the verb gap for Down syndrome stayed.

03

How this fits with other research

Facon et al. (2012) saw no special Down syndrome profile once total vocabulary was equal. The new study keeps IQ equal and still finds a verb weakness, so the profile shows up only when you split words by type.

Laugeson et al. (2014) first spotted the noun-verb gap in preschoolers. This paper widens the lens to older youth and adds an ID control, proving the verb lag is not just a delay seen in little kids.

Neitzel (2024) later showed that richer verb use in stories makes better narratives for Down syndrome teens. Together the papers form a line: weak verb comprehension (2016) leads to limited verb diversity in stories (2024), giving you a clear skill to target.

04

Why it matters

When you test receptive vocabulary, always report separate noun and verb scores. Goals can jump ahead of the verb gap by teaching action words first, using pictures, signs, or AAC. Track verb gains; they may unlock both following directions and later storytelling skills.

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→ Action — try this Monday

Add ten verb cards to your receptive ID program and record correct pointing separately from noun scores.

02At a glance

Intervention
not applicable
Design
quasi experimental
Sample size
108
Population
down syndrome, intellectual disability, neurotypical
Finding
mixed

03Original abstract

The present study is an in-depth examination of receptive vocabulary in individuals with Down syndrome (DS) in comparison to control groups of individuals of similar nonverbal ability with typical development (TD) and non-specific etiology intellectual disability (ID). Verb knowledge was of particular interest, as it is known to be a predictor of later syntactic development. Fifty participants with DS, aged 10-21 years, 29 participants with ID, 10-21 years, and 29 participants with TD, 4-9 years, completed measures of receptive vocabulary (PPVT-4), nonverbal ability (Leiter-R), and phonological memory (Nonword Repetition subtest of the CTOPP). Groups were compared on percentage correct of noun, verb and attribute items on the PPVT-4. Results revealed that on verb items, the participants with ID performed significantly better than both participants with DS and TD, even when overall receptive vocabulary ability and phonological memory were held constant. Groups with DS and TD showed the same pattern of lexical knowledge, performing better on nouns than both verbs and attributes. In contrast, the group with ID performed similarly on nouns and verbs, but worse on attributes.

Research in developmental disabilities, 2016 · doi:10.1016/j.ridd.2016.03.018