Table 3.

CSBS and MSEL means (SDs) for LRC, HRA−, and HRA+

	LRC	HRA−	HRA+	Group Differences*
CSBS-DP (12 mo)	n = 40	n = 32	n = 18
Social Percentile	56.15 (26.86)	42.59 (32.32)	32.06 (28.02)	LRC > (HRA− = HRA+)
Range	2–98	2–99	1–84
CSBS-DP (18 mo)	n = 34	n = 31	n = 14
Social Percentile	66.79 (24.16)	51.51 (27.79)	49.71 (34.82)	LRC > HRA−
Range	16–99	2–99	2–98
MSEL (12 mo)	n = 46	n = 37	n = 22
ELC	106.28 (12.22)	102.59 (15.54)	98.00 (15.90)	LRC > HRA+
Range	77–134	70–138	72–131
MSEL (18 mo)	n = 40	n = 37	n = 19
ELC	107.28 (14.83)	99.30 (16.76)	91.58 (19.39)	LRC > (HRA− = HRA+)
Range	76–133	72–131	63–132

Note: LRC: Low-risk controls; HRA−: High-risk autism with no ASD diagnosis; HRA+: High-risk autism with ASD diagnosis; CSBS-DP: Communication and Symbolic Behavior Scales - Developmental Profile; MSEL: Mullen Scales of Early Learning; ELC: Early Learning Composite score; CSBS-DP at 12mo missing for 10 LRC, 7 HRA−, and 4 HRA+; CSBS-DP at 18mo missing for 16 LRC, 8 HRA−, and 8 HRA+; MSEL at 12mo missing for 4 LRC and 2 HRA−; MSEL at 18mo missing for 10 LRC, 2 HRA− and 3 HRA+ (see Method for more detail).

^*p < .05