The initial externalizing factor model (illustrated in Figure 1) demonstrated excellent fit: RMSEA = 0.020, CFI = 0.952, TLI = 0.950, χ2(1987) = 3719.97, p < 0.001. Standardized factor loadings for all paths in the model are presented in Table 1. We next tested if measurement invariance held across biological sex using multigroup modeling features of Mplus. A model that allowed for all loadings to be free by sex (but retained the constraint of equality over time) had slightly better fit indices (RMSEA = 0.019, CFI = 0.951, TLI = 0.949, χ2(4017) = 5643.899, p < 0.001) than a model constraining all loadings to be equal across the sexes (RMSEA = 0.021, CFI = 0.937, TLI = 0.936, χ2(4089) = 6187.347, p < 0.001). Although this appeared to be a significant decrement in model fit when using a chi-square difference test, Δχ2(72) = 307.918, p < 0.001, this form of comparative model testing can be sensitive to relatively trivial differences in model fit when the sample size is large. Thus, we re-scaled χ2 differences to an RMSEA metric (Hildebrandt, Wilhelm,
