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Mean (SD) and range of expressive vocabularya at 18 and 24 months for all participants and by SES sub-groupb
| Age | All participants | Lower SES | Higher SES | |||
|---|---|---|---|---|---|---|
| 18 months | 141.9 (123.0) | 5 - 503 | 107.0 (114.2) | 5 - 503 | 174.0 (124.3) | 16 - 471 |
| 24 months | 367.9 (180.2) | 4 - 665 | 287.9 (163.3) | 4 - 573 | 441.5 (165.4) | 59 - 665 |
Number of words produced on the MacArthur-Bates CDI: Words & Sentences (Fenson et al., 2006).
SES groups based on a median split of HI scores.
