Figure 1.

Model including genetic and environmental effects, sibling effects, and social homogamy on tinnitus for a nuclear family including parents with two children. Capital letters G, E in circles denote the latent variables for genetic and environmental effects, respectively. S denotes environmental factors common to siblings. P denotes phenotype (tinnitus). Parameters (small letters): g = genetic effect, e = environmental effect, s = environmental effects shared by siblings (sibling effect). Subscript F=female, M=male, C1=child number 1 (female in this diagram), C2=child number 2 (male in this diagram). σ = correlation between male and female sibling environmental effect, µ = correlation between spouses’ environment (social homogamy).