used as in all other analyses (age, gender, generation, recording system, and the 10 PCs from EIGENSTRAT). Because LD can bias SNP heritability estimates upward (Speed, Hemani, Johnson, & Balding, 2012), we repeated the three analyses after weighting SNPs by local LD patterns. It has been recommended more recently when the sample consists of closely related individuals to estimate the total genetic variance while modeling the environmental influences family members share (the C latent variable in biometric models) (Yang et al., 2013). This produces an estimate of genetic influence unconfounded by shared environmental influence. In addition to this, we conducted the same analysis without modeling shared environmental influences (i.e., without any threshold of genetic relatedness). These two analyses, one that models C and one that does not, allowed us to assess the influence of shared environmental effects by comparing the two estimates.
