Table 1. Descriptive Statistics for Predictor Variables.

Variable	Mean	S.D.	Range	Frequency
Substance Use at 17.5 by SU Group
Alcohol Use (Past 6 months)
Abstainers (n = 18)	0	0	0
Experimenters (n = 58)	1.02	2.83	0-20
At-risk (n = 58)	4.16	6.64	0-38
Abusers (n = 25)	16.67	29.25	0-124
Marijuana Use (Past 6 months)
Abstainers	0	0	0
Experimenters	.48	2.67	0-20
At-risk	6.29	18.59	0-100
Abusers	66.50	75.04	0-224
Other Drug Use (Past 6 months)
Abstainers	0	0	0
Experimenters	0	0	0
At-risk	.36	2.04	0-15
Abusers	2.00	5.47	0-25
Control Variables
Gender				Male = 79 Female = 80
I.Q.	104.30	15.37	56-142
Externalizing Behaviors at 16 years	55.46	9.07	40-80
Internalizing Behaviors at 16 years	53.67	8.24	38-76
Peer Competence at 16 years	51.90	25.82	3.33-100
Parental Monitoring	1.99	.55	1-3
Current Substance Use at 26
Abstainers	1.28	.9	0-3
Experimenters	1.50	1.06	0-4
At-risk	1.84	1.34	0-5
Abusers	2.56	1.45	0-6