Table 1.

Demographic information. Abbreviations: TD = typically developing; DD = developmental delay of unknown origin; FXS = fragile X syndrome; iAUT = idiopathic autism.

		TD	DD	FX	iAUT	ANOVA		Post-Hoc
						F	P	P
SU:UNC a	N	11:20	11:8	28:24	17:46	11.32	0.01
Age	N	31	19	52	63			FX > TD*, DD > TD*
	Mean	2.55	2.96	2.90	2.77	3.65	0.014
	SD	0.60	0.50	0.63	0.41
Mullen	N	31	19	52	63			FX < TD***, iAUT < TD***, DD < TD***
	Mean	109.55	55.47	54.94	54.10	207.13	<0.001
	SD	17.24	7.53	9.14	9.41
RBS	N	16	14	37	16			FX > TD***, iAUT > TD***, > DD*
	Mean	3.13	13.07	18.70	26.25	12.69	<0.001
	SD	4.27	12.42	11.08	14.36
ADI Rep Total	N			50	63
	Mean			3.12	4.84	30.39	<0.001
	SD			1.49	1.76
ADI Social Total	N			50	63
	Mean			9.18	18.62	125.53	<0.001
	SD			4.92	4.04
ADI Comm. Verbal	N			5	5
	Mean			6.80	12.80	5.56	<0.05
	SD			5.07	2.59
ADI Comm. Nonverbal	N			45	58
	Mean			9.09	11.59	18.23	<0.001
	SD			3.74	2.12
ADI Sum [Verbal]	N			5	5
	Mean			18.20	35.60	11.09	0.01
	SD			10.92	4.16
ADI Sum [Nonverbal]	N			44	58
	Mean			26.43	39.52	80.63	<0.001
	SD			8.90	5.78
Adjusted ADI Sum	N			49	63
	Mean			0.93	1.43	81.53	<0.001
	SD			0.36	0.23
ADOS Soc/Com Total	N			52	54
	Mean			10.19	18.00	80.05	<0.001
	SD			5.71	2.87
ADOS Severity Measure	N			52	53
	Mean			4.10	7.62	85.12	<0.001
	SD			2.38	1.43
FMRP	N			50
	Mean			5.83
	SD			3.94

Mullen: Mullen Composite Standard Score, RBS: Repetitive Behavior Score Overall Total Score, ADI: Autism Diagnostic Interview, Sum of Socialization, Communication (Verbal or Non-verbal), ADOS: Autism Diagnostic Observation Scale, Repetitive and Stereotype

^aPearson Chi-square performed. No significant difference in any of the measures between sites (SU and UNC) for each disgnostic group.