We first compared the three structures for shared environmental (C) sources of variance, while the genetic (A) and unique environmental (E) variance structures were in a hypothesis-free state (i.e., in a Cholesky decomposition). Table 1 provides AIC/BIC values and −2 times the log likelihoods (−2LL) of fit for the three hypothesized latent factor structures. For both C and A, based on the best AIC/BIC values, we selected the structure shown in Supplementary Figure 1b, in which one common factor loads onto SELF1-SELF4, and a second common factor loads onto PEER1-PEER4; these two factors are correlated (rC=0.99, which was the upper bound of this path in the model, but see below; rA=0.83). The best-fitting model for E was the 8-factor model described previously, and depicted in Supplementary Figure 1a, with forward transmission within phenotype across time, and both social influence and social selection paths.
