We sought to further confirm the above results using the bivariate G × E model (Purcell, 2002), as recommended by van der Sluis et al. (2012). For observer ratings of parental negativity, the unique C moderator was estimated at 0.20 (p < 0.05) and the common C moderator was estimated at 0.00. For parent–child conflict, the unique C moderator was estimated at 0.08 (p < 0.05) and the common C moderator was estimated at 0.05. Although this latter moderator was also statistically significant, the unique moderator results are generally very similar to those reported in Table 3, serving to bolster our conclusion that parent–child conflict/parental negativity moderates shared environmental influences on CP.
