Table 2.

Descriptive Statistics of Study Variables across Samples

	Sample 1			Sample 2
Variable	M	SD	Range	Variable	M	SD	Range
MSSD	21.46	22.56	0–136	MSSD	10.27	8.63	.17–.43.31
MIS	7.48	2.54	4.00–14.50	MISa	4.03	2.21	.25–11.50
NU	2.36	.50	1.00–3.33	NU	2.33	.59	1.17–3.83
PU	2.00	.59	1.00–3.43	PU	1.84	.59	1.00–4.00
SS	3.15	.53	1.67–4.00	SS	3.08	.57	1.42–4.00
LPer	1.83	.44	1.00–3.10	Per	3.11	.54	1.70–4.00
LPlan	1.93	.47	1.09–3.18	Plan	3.17	.45	1.27–4.00
bGS	31.04	18.50	.00–80.00
fGS	24.55	18.58	.00–70.00
bIMT	.35	.15	.06–.68
fIMT	.33	.16	.03–.74
bTCIP	16.73	12.80	.00–50.00
fTCIP	21.40	18.73	.00–50.00

Note. M = mean; SD = standard deviation; MSSD = mean squared successive difference of MIS scores; MIS = aggregate MIS scores (averaged across 10 days of assessment); NU = UPPS-P negative urgency; PU = UPPS-P positive urgency; SS = UPPS-P sensation seeking; LPer = UPPS-P lack of perseverance; Per = UPPS-P perseverance; LPlan = UPPS-P lack of planning; Plan = UPPS-P planning; bGS = baseline GoStop percentage of response inhibition failures; fGS = follow-up GoStop percentage of response inhibition failures; bIMT = baseline IMT ratio; fIMT = follow-up IMT ratio; bTCIP = baseline number of immediate choices; fTCIP = follow-up number of immediate choices; Sample 1 baseline n = 75–77; Sample 1 follow-up n = 63–66. Sample 2 baseline n = 126–147.

^aMIS scores from Sample 2 (i.e., using a 0–100 sliding scale) were rescaled by dividing by 20 to facilitate direct comparisons between samples.