Table 1.

Participant Characteristics

Characteristic	Down syndrome			Typically developing
	M/%	SD	Range	M/%	SD	Range
Child
Chronological Age (in months)	11.67	3.29	7–18	11.54	1.71	9–14
AOSI Total Score	9.28	4.91	3–20	4.72	3.41	1–15
AOSI Markers Score	5.89	2.49	3–10	3.33	1.97	1–8
Early Learning Composite	68.31	12.40	49–93	96.44	13.01	71–115
Overall Mental Age (in months)	8.03	2.41	4.25–13.00	11.79	3.39	7–21.75
Nonverbal Abilities Composite	32.25	9.45	20–48.50	51.22	10.02	32.50–65.50
Verbal Abilities Composite	33.09	7.24	20.50–46.50	44.92	6.51	36–57.50
Expressive Language T-Score	34.81	8.07	20–45	47.22	9.88	29–66
Receptive Language T-Score	31.38	8.28	20–49	42.61	7.37	34–58
Child Race/Ethnicity (%)
White	55.5			77.8
African American	5.6			16.7
Hispanic	5.6			-
More than One Race/Ethnicity	5.6			5.6
Unknown/Choose Not to Respond	27.8			-