Table 6.

Predictive Utility of Psychopathy Across Development—Model II

Estimating parameters for the low-risk groupa
Parameter	Estimate	Standard error	P-value
β0 (intercept)	2.4089	0.9988	0.0159
β1 (previous delinquency)	0.2852	0.05320	< 0.0001
β2 (previous psychopathy)	0.4060	0.2446	0.0971
β3 (age)	−6.3400	2.4731	0.0104
β4 (age-squared)	6.1660	1.9972	0.0020
β5 (age-cubed)	−1.7810	0.5211	0.0006
β6 (previous del. X age)	−0.06137	0.04040	0.1288
β7 (previous psych. X age)	−0.00635	0.1931	0.9738
β8 (6 months or 1 year)	0.3125	0.06475	< 0.0001
Estimating parameters for the high-risk groupa
Parameter	Estimate	Standard error	P-value
β0 (intercept)	1.5128	1.0289	0.1415
β1 (previous delinquency)	0.2530	0.04781	< 0.0001
β2 (previous psychopathy)	0.6077	0.2405	0.0116
β3 (age)	−3.4561	2.4857	0.1644
β4 (age-squared)	5.0782	1.9858	0.0106
β5 (age-cubed)	−1.7742	0.5135	0.0006
β6 (previous del. X age)	−0.06045	0.03680	0.1006
β7 (previous psych. X age)	−0.1307	0.1828	0.4748
β8 (6 months or 1 year)	0.1478	0.06512	0.0233
Estimate of residual error variance: 2.2232
Results for hypothesis tests of interest
Null hypothesis	DF	Chi-square	P-value
β1 = β6 = 0 in both groups	4	472.20	< 0.0001
β2 = β7 = 0 in both groups	4	83.80	< 0.0001
β5 = 0 in both groups	2	23.62	< 0.0001
β8 = 0 in both groups	2	28.44	< 0.0001
β6 = 0 in both groups	2	5.01	0.0820
β7 = 0 in both groups	2	0.51	0.7742
fixed effects equal in both groups	9	349.95	< 0.0001
β1, β6 equal in both groups	2	3.04	0.2187
β2, β7 equal in both groups	2	0.48	0.7868

^aThe parameters β₀ through β₈ are the intercept and coefficients for X_ij′, Y_ij′, A_ij, A_ij², A_ij³, X_ij′, A_ij, Y_ij′A_ij, and S_ij respectively.