Table 2.

Model fit statistics for latent growth curve models of 4 primary variables of interest (shaded area indicates selected model)

Model	BIC	Χ 2	Χ 2 / df	CFI	TLI	RMSEA
Socialization
Intercept only	11 775.88	133.87	5.15	0.797	0.836	0.112
Linear	11 710.18	53.17	2.31	0.943	0.948	0.063
Quadratic	11 708.12	29.32	1.54	0.981	0.978	0.041
Cubic	11 729.14	22.99	1.64	0.983	0.975	0.044
Social Problems
Intercept only	8398.88	78.37	3.01	0.864	0.890	0.082
Linear	8365.42	40.08	1.74	0.956	0.960	0.050
Quadratic	8368.61	25.04	1.32	0.984	0.983	0.032
Estimated IQ
Intercept only	11 549.71	234.39	12.33	0.829	0.865	0.180
Linear	11 458.83	138.48	8.65	0.903	0.909	0.148
Quadratic	11 392.50	45.36	3.78	0.973	0.967	0.089
Attention Problems
Intercept only	8552.29	71.68	2.76	0.882	0.904	0.076
Linear	8517.17	38.99	1.69	0.959	0.962	0.048
Quadratic	8514.20	22.41	1.18	0.991	0.990	0.024
Cubic	8535.06	17.00	1.21	0.992	0.988	0.027

BIC: Bayesian information criteria; CFI: Comparative Fit Index; df: degrees of freedom; RMSEA: root mean square error of approximation; TLI: Tucker Lewis Index.

Note. Cubic models would not converge for socialization, social problems, and estimated IQ.