Table 1. Observed means and standard deviations for covariates, total externalizing, and the five externalizing subfactors, estimated together and separately by gender.

	All (N = 543)		Male (n = 282)		Female (n = 261)
	Mean	SD	Male	SD	Female	SD	t Test/χ2
Covariates
SES (Hollingshead)	39.59	14.03	40.21	14.07	38.92	13.98	1.07, ns
African American	0.17		0.16		0.18		0.28, ns
Total Externalizing
Kindergarten	0.20	0.29	0.25	0.33	0.15	0.25	4.09***
First grade	0.25	0.33	0.32	0.37	0.17	0.25	5.37***
Second grade	0.26	0.35	0.32	0.36	0.20	0.34	3.77***
Third grade	0.25	0.34	0.33	0.38	0.17	0.28	5.41***
Fourth grade	0.25	0.35	0.33	0.39	0.16	0.28	5.20***
Fifth grade	0.26	0.33	0.35	0.37	0.18	0.26	5.51***
Sixth grade	0.26	0.35	0.33	0.36	0.18	0.33	4.40***
Seventh grade	0.24	0.33	0.30	0.35	0.18	0.30	3.97***
Eighth grade	0.26	0.36	0.34	0.39	0.18	0.32	4.23***
Externalizing Subfactors
Overt aggression
Kindergarten	0.11	0.28	0.14	0.31	0.08	0.23	2.61**
First grade	0.12	0.28	0.16	0.32	0.07	0.22	3.48***
Second grade	0.13	0.32	0.15	0.31	0.12	0.32	0.95, ns
Third grade	0.13	0.32	0.17	0.37	0.08	0.24	3.38***
Fourth grade	0.14	0.32	0.19	0.38	0.08	0.24	3.71***
Fifth grade	0.13	0.30	0.19	0.37	0.07	0.20	4.05***
Sixth grade	0.13	0.30	0.15	0.31	0.10	0.29	1.60, ns
Seventh grade	0.09	0.24	0.11	0.25	0.07	0.23	1.52, ns
Eighth grade	0.12	0.32	0.14	0.34	0.10	0.29	1.51, ns
Covert aggression
Kindergarten	0.09	0.29	0.09	0.28	0.08	0.29	0.31, ns
First grade	0.11	0.32	0.11	0.30	0.11	0.34	−0.25, ns
Second grade	0.13	0.35	0.13	0.31	0.14	0.39	−0.40, ns
Third grade	0.12	0.34	0.13	0.35	0.10	0.32	0.80, ns
Fourth grade	0.14	0.35	0.16	0.37	0.12	0.32	1.20, ns
Fifth grade	0.12	0.30	0.14	0.32	0.11	0.28	1.20, ns
Sixth grade	0.11	0.30	0.11	0.30	0.11	0.30	0.17, ns
Seventh grade	0.09	0.26	0.13	0.30	0.06	0.20	2.70**
Eighth grade	0.11	0.29	0.16	0.33	0.08	0.22	2.87**
Oppositional defiant
Kindergarten	0.28	0.45	0.34	0.50	0.20	0.38	3.71***
First grade	0.33	0.49	0.44	0.56	0.21	0.38	5.49***
Second grade	0.35	0.51	0.45	0.55	0.23	0.45	4.77***
Third grade	0.32	0.49	0.43	0.55	0.20	0.38	5.37***
Fourth grade	0.32	0.49	0.44	0.55	0.20	0.40	5.27***
Fifth grade	0.35	0.48	0.47	0.53	0.22	0.38	5.83***
Sixth grade	0.35	0.50	0.47	0.55	0.22	0.41	5.23***
Seventh grade	0.34	0.48	0.44	0.52	0.24	0.42	4.27***
Eighth grade	0.37	0.54	0.49	0.59	0.25	0.47	4.36***
Temperament Subfactors
Inattention/impulsivity
Kindergarten	0.31	0.42	0.39	0.46	0.21	0.33	5.21***
First grade	0.41	0.48	0.52	0.53	0.28	0.37	6.00***
Second grade	0.41	0.47	0.52	0.50	0.29	0.42	5.58***
Third grade	0.39	0.46	0.51	0.50	0.25	0.36	6.60***
Fourth grade	0.38	0.47	0.51	0.52	0.24	0.37	6.54***
Fifth grade	0.40	0.46	0.53	0.50	0.26	0.36	6.50***
Sixth grade	0.38	0.47	0.51	0.51	0.24	0.39	6.17***
Seventh grade	0.38	0.48	0.49	0.51	0.27	0.43	4.76***
Eighth grade	0.41	0.51	0.54	0.54	0.27	0.44	5.36***
Emotion dysregulation
Kindergarten	0.11	0.24	0.13	0.27	0.10	0.20	1.44, ns
First grade	0.15	0.33	0.17	0.35	0.13	0.30	1.41, ns
Second grade	0.14	0.32	0.15	0.32	0.14	0.31	0.36, ns
Third grade	0.15	0.31	0.18	0.35	0.12	0.25	2.23*
Fourth grade	0.15	0.30	0.19	0.35	0.11	0.24	2.75**
Fifth grade	0.17	0.32	0.20	0.36	0.14	0.26	2.04*
Sixth grade	0.18	0.35	0.20	0.35	0.17	0.36	0.95, ns
Seventh grade	0.14	0.31	0.15	0.32	0.14	0.30	0.26, ns
Eighth grade	0.17	0.33	0.17	0.32	0.17	0.35	−0.11, ns

Note: SES, socioeconomic status.

^*p < .05.

^**p < .01.

^***p < .001.