Table 2.

Fixed effects, random effects, and model fits for unconditional means model (Model 1) and basic growth curve models (Model 2) of square-root-transformed internalizing symptoms from ages 4 to 10. Model 3 is a basic growth model that uses a dichotomized age term (1 = 10.5 yrs old, 0 = 4 to 7 yrs old). N = 1,311 observations from 384 children.

	Model 1 Unconditional Model		Model 2 Basic Growth Curve		Model 3 Dichotomous Age10 Term
	Estimate	SE	Estimate	SE
Fixed Effects
Intercept	1.814***	0.052	1.946**	0.304	1.781***	0.099
Race (1=Caucasian)			0.071	0.107	0.070	0.108
Age			-0.085	0.090	0.349***	0.073
Age2			0.010	0.006
Sex (1 = Male)			-0.920*	0.422	-0.144	0.103
Age by Sex			0.265*	0.127	-0.330**	0.102
Age2 by Sex			-0.021*	0.008
Random Effects
Intercept	0.848**	0.074	1.050**	0.164	0.825***	0.074
Age			0.011**	0.003	0.213**	0.079
Residual	0.539**	0.025	0.440**	0.025	0.474***	0.027
ICC	.61
Model Fit
REML Deviance	3608.6		3579.6		3559.3
AIC	3612.6		3587.6		3567.3
BIC (smaller is better)	3620.5		3603.4		3583.1

^***p < .001

^**p < .01

^*p < .05,

⁺p < .10

Acronyms: REML = Restricted Maximum Likelihood; AIC = Akaike's information criterion; BIC = Bayesian information criterion; ICC = Intraclass correlation.

ICC was calculated as follows: Intercept random effect/(Intercept random effect + Residual Random Effect)