To determine which LGMs best fit the data, three unconditional LGMs were modeled for each construct of interest: intercept only, linear (intercept and linear slope), and nonlinear (intercept and a nonlinear slope; Meredith & Tisak, 1990). For all four variables of interest, the nonlinear model was best fitting (see Table 4). This model involved linear coding of the measurement occasions corresponding approximately to ages 18–29 with the last time of measurement (approximate age 35) estimated freely, reflecting a leveling off of the rate of change as participants entered into the 4th decade of life. Furthermore, all longitudinally measured constructs exhibited significant variability in both the intercept and the slope, indicating the presence of meaningful individual differences in study constructs in both the initial level (at approximate age 18) and the rate of change over the study period (see Table 5).
