We fit a full model estimating all paths. 95% confidence intervals were used to determine significance of path estimates. We also used a nested model approach, commonly used to verify the findings from the full models in twin studies (Neale & Cardon, 1992) and the ECOT model (Marceau et al., 2013; Narusyte et al., 2011), where we systematically dropped paths m (parent-to-child) and n (child-to-parent) in order to verify the significance (identified by a significant decrement in model fit when the path estimate was fixed to 0). This approach was also used to verify the other paths deemed non-significant based on confidence intervals separately and as a group. Only parameter estimates from the full model are presented and interpreted.
