Figure 1. Path Diagram for the Full Twin Moderation Model for One Twin Only.

A = additive genetic effects; c = shared environmental effects; e = nonshared environmental effects; M = moderator (i.e., estradiol levels); triangle = mean for MEBS total score or weight/shape concerns factor score; ${\beta }_{\text{M}}$ phenotypic regression coefficient; a, c, and e = paths or intercepts; ${\beta }_{\text{x}}$, ${\beta }_{\text{Y}}$, ${\beta }_{\text{Z}}$ = linear moderators; ${\beta }_{x^2}{M}^2$, ${\beta }_{y^2}{M}^2$, ${\beta }_{z^2}{M}^2$ = quadratic moderators.