Chapter 15 / Part Three / From Baby to Toddler
Language Development
Vocabulary ranges, late talking, bilingualism, and screening.
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Core idea: Early vocabulary varies enormously. Language timing contains some information about later outcomes, but not enough to predict an individual child's future; screening is useful, comparison-driven forecasting is not.
One-Minute Recap#
- Vocabulary growth differs dramatically among healthy children of the same age.
- Girls use more words earlier on average, but the distributions for boys and girls overlap substantially.
- A bilingual child's words are distributed across languages, so a one-language comparison can understate total communication.
- Standard parent-report tools can make vocabulary discussions more concrete.
- Late talking is correlated with somewhat lower average later language scores, but most late talkers enter the normal range.
- Early talking is not a reliable guarantee of later academic success or giftedness.
- Individual variation within early- and late-talking groups is much larger than the average difference between groups.
Guidance at a Glance#
| Label | Takeaway |
|---|---|
| RECOMMENDED - Moderate | Use a validated developmental screen and pediatric assessment when language seems delayed. |
| MUST - High | Promptly report loss of words/communication skills, loss of social engagement, hearing concerns, or regression. |
| RECOMMENDED - Moderate | Consider early-intervention evaluation when the pediatrician or screening tool identifies concern; evaluation does not commit the child to a diagnosis. |
| RECOMMENDED - Moderate | Talk, read, sing, respond, and take conversational turns with the child in the language(s) natural to the family. |
| SKIP - High | Skip forecasts based on whether a child talks earlier or later than peers within the broad normal range. |
| SKIP - High | Do not treat bilingual exposure as a language problem based only on one-language word counts. |
Numbers Worth Remembering#
- At 24 months, the cited vocabulary distribution runs from roughly 75 words at the 10th percentile to 550 at the 90th, with a midpoint around 300.
- One commonly used discussion threshold is fewer than about 25 words at 24 months, but a clinician should interpret it alongside comprehension, gestures, hearing, social communication, and development in other domains.
- Early vocabulary has some statistical link to later language scores, but the overlap between groups is very large.
Practical Playbook#
Observe Communication Broadly#
- Words across all languages.
- Gestures, pointing, imitation, eye contact, and back-and-forth interaction.
- Understanding of words and simple directions.
- New skills appearing over time.
- Hearing and response to sounds.
Support Language Without Turning It Into a Test#
- Follow the child's attention and name what they notice.
- Pause for a response and treat gestures or sounds as conversational turns.
- Read interactively and ask age-appropriate open questions.
- Repeat and expand: if the child says "dog," respond with "Yes, the brown dog is running."
- Use the home languages caregivers speak comfortably and richly.
When Concern Persists#
- Bring examples and a short word/gesture list to the pediatrician.
- Ask whether hearing testing, speech-language assessment, or early intervention is appropriate.
- Do not wait for a precise prediction of the future before accepting low-risk support.
What Is Still Uncertain#
- Why a particular child talks early or late and whether an observed difference is causal.
- The extent to which parent-report vocabulary tools capture every culture, region, and language equally well.
- How much an early vocabulary difference matters for one child's outcomes years later.
My Family Notes#
- Languages used at home:
- Current words, gestures, and comprehension:
- Progress noticed over the last month:
- Hearing or social-communication questions:
- Pediatrician/early-intervention follow-up: