APPENDIX 1.

Intercorrelations among study variables by child.
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17
1. IC	1	−.13	−.05	.08	.29a	.05	.12	.15	.14	.18*	−.09	−.09	.01	−.16 c	.22b	.09	−.06
2. SDP (CS)	−.04	1	−.15	−.20b	−.14	−.05	−.17 c	−.02	−.21b	−.07	.12	.19*	.29a	.15	−.06	.03	.01
3. SDP (FA)	−.06	.15	1	.03	−.01	−.13	−.02	−.05	.09	.04	−.08	−.04	−.01	.20b	−.19 c	−.18 c	−.06
4. IQ (CS)	.19c	−.20b	−.03	1	−.01	.04	−.02	<.01	.09	−.01	.17 c	<.01	−.04	−.02	−.04	−.03	.08
5. IQ (FA)	.41a	.14	−.01	.01	1	<.01	.38a	.01	.19 c	.22b	−.1	−.18 c	−.14	−.09	.19 c	.03	.06
6. Mother EDU (CS)	<.01	−.05	.13	.04	.01	1	−.15	.1	.03	.03	.01	−.03	−.04	−.08	.07	.04	−.07
7. Mother EDU (FA)	.01	.17b	−.10	.02	.39a	.16 c	1	.05	.52a	.25b	−.1	−.28a	−.1	−.18 c	.13	.07	.17 c
8. Mother Age (CS)	.12	−.01	.03	−.01	.06	.10	.03	1	.12	.28a	−.13	−.22b	<.01	−.05	.17 c	−.06	.13
9. Mother Age (FA)	−.05	.21b	.09	−.09	.19 c	−.03	.52a	−.09	1	.29a	−.09	−.22b	−.20 c	−.24b	.11	.17 c	.15
10. Mother Marital Status	−.05	.05	.05	−.01	.19 c	−.02	.20 c	−.22b	.26 b	1	−.13	−.37a	−.04	.05	.04	−.04	.11
11. Food Stamps (CS)	−.05	.12	.08	.18 c	.10	.01	.10	−.14	.09	.15	1	.15	.13	.03	−.08	.02	−.05
12. Food Stamps (FA)	.01	−.19 c	−.04	<.01	−.19 c	.03	−.28a	.22b	−.22b	−.31a	−.15	1	<.01	.08	−.15	−.01	.01
13. SHSE (CS)	.01	.29a	.02	−.03	.15	−.03	.11	.01	.22b	.04	.14	−.04	1	−.02	−.03	−.06	−.02
14. SHSE (FA)	−.02	−.15	.20b	.02	−.11	.08	−.16 c	.04	−.24b	.08	−.03	.08	.01	1	−.17c	−.25b	−.1
15. Mother IC	.30a	.06	−.19 c	.04	.18 c	−.06	.13	−.14	.12	<.01	.08	−.16	.03	−.18 c	1	.03	−.04
16. Sex (CS)	.07	.03	.18 c	−.03	−.03	.04	−.07	−.05	−.17 c	.05	.02	.01	−.05	.25b	−.03	1	<.01
17. Sex (FA)	.03	−.01	−.06	−.08	.04	.09	.17 c	−0.05	.16 c	.05	.06	<.01	.01	−.11	−.06	<.01	1

Note. Child 1 correlations are below the diagonal; child 2 correlations are above the diagonal. IC=Inhibitory control; SDP=smoking during pregnancy; CS= child specific; FA= family average; EDU= education; SHSE=second-hand smoke exposure

^ap<.001;

^bp<.01;

^cp<.05