Table 1.

Bivariate correlations, means, and standard deviations for main study variables

Variable	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
1. Race
2. Family income-to-needs ratio	−.40***
3. Sex	−.02	.06
4. zBMI	.12	.02	.03
5. Illness/asthma	.07	−.09	.10	−.04
6. ADHD	−.04	−.03	.06	−.17**	.08
7. Sleep duration: age 9	−.12	.14*	−.11	−.22**	−.11	.04
8. Sleep/wake problems: age 9	.30**	−.21**	.01	.06	−.02	.05	−.06
9. Sleepiness: age 9	.25***	−.15*	−.06	−.01	−.04	−.01	.01	.44**
10. Academic functioning: age 9	−.25***	.30***	−.08	.05	−.06	−.25***	.15*	−.18*	−.21**
11. BIA: age 9	−.25***	.25***	−.01	.05	−.11	−.16*	.01	−.11	−.24***	.51***
12. Alabama test total: age 9	−.22**	.22**	−.02	.07	−.03	−.21**	.01	−.18*	−.35***	.62***	.76***
13. Academic functioning: age 11	−.06	.27*	−.14	.07	−.05	−.33**	.07	−.20	−.41***	.70***	.57***	.57***
14. BIA: age 11	−.27***	.29***	.01	.11	−.07	−.17*	.00	−.15*	−.30***	.55***	.81***	.79***	.63***
15. Alabama test total: age 11	−.20*	.24**	.07	.14	.01	−.25**	.04	−.16*	−.27**	.68***	.72***	.80***	.72***	.76
M	-	1.71	-	0.61	-	-	458.31	18.97	14.68	0.00	494.57	1277.30	0.00	507.27	1353.16
SD	-	1.04	-	1.15	-	-	56.16	5.23	4.61	1.78	10.34	73.01	1.77	11.20	65.47

Race was coded as 0 = EA, 1 = AA. Sex was coded as 0 = female, 1 = male. Illness/asthma and ADHD were coded as 0 = absent, 1 = present. Academic functioning was the sum of standardized academic performance and academic habits variables. Prior to standardization, academic performance M (SD) = 28.28 (6.16) and 26.53 (6.78) at ages 9 and 11, respectively. Academic habits M = 45.84 (7.95) and 46.01 (6.65) at ages 9 and 11.

^*P ≤ .05,

^**P < .01,

^***P < .001.