Table 2.

Correlations of study variables at baseline

Variable	1	2	3	4	5	6	7	8	9	10	11
1. Sex	–
2. Age	.08**	–
3. Living situation	.04*	−.07**	–
4. Family substance use history	−.07**	−.01	−.14**	–
5. Low parental education level	−.06**	.01	−.03	.04*	–
6. Alternative reinforcement W1	−.10**	−.03	.08**	−.05**	−.13**	–
7. Alternative reinforcement W3	−.11**	−.02	.07**	−.04*	−.09**	.51**	–
8. Complementary reinforcement W1	.03	.08**	−.08**	.04*	.09**	−.19**	−.12**	–
9. Complementary reinforcement W3	.04*	.06**	−.05*	.04*	.05*	−.11**	−.21**	.30**	–
10. Number of substances used in past 30 days W1	−.04*	.04*	−.11**	.11**	.15**	−.20**	−.15**	.50v	.23**	–
11. Number of substances used in past 30 days W2	−.06**	.06**	−.11**	.11**	.16**	−.15**	−.20**	.35**	.31**	.54**	–
12. Number of substances used in past 30 days W4	−.02	.02	−.08**	.08**	.10**	−.10**	−.20**	.22**	.33**	.41**	.54**

Note. Low parental education level was coded as follows: 0 = high school graduate or higher degree, 1 = parent(s) without high school diploma. Sex was coded as follows: 0 = female, 1 = male. Living situation was coded as follows: 0 = other type of living situation, 1 = living with both parents. Family substance use history was coded as follows: 0 = none, 1 = family history of substance use.

^*p < .05.

^**p < .01.