Table 1.

Participant demographics for Down syndrome and typically-developing control groups.

	Down syndrome (n = 19)			Control (n = 33)			Stat. significance
	M	SD	Range	M	SD	Range
Age	16.53	4.99	7–23	17.53	5.15	9–24	n.s.
IQ	53.21	13.19	24–77	116.30	13.37	85–151	t(50) =  − 16.46, p < 0.001
Verbal IQ	54.42	14.97	30–71	117.12	13.51	82–156	t(50) =  − 15.5, p < 0.001
Nonverbal IQ	56.42	16.00	24–86	112.64	15.58	81–151	t(50) =  − 12.41, p < 0.001
Hollingshead SESa	41.68	15.69	20–63	37.31	20.77	20–115	n.s.

	n	%		n	%		Stat. significance
Male, n (%)	6	32		15	45		n.s.
Right hand, n (%)b	12	63		25	76		n.s.
White, Non-hispanic, n (%)	15	79		22	67		n.s.

^aDown syndrome, n = 19; Control, n = 29.

^bDown syndrome, n = 18; Control, n = 33.