"Objective: Eating pathology has been found to aggregate in families. Typically, familial resemblance has been attributed to parents providing an environment that leads to the development of eating pathology. However, offspring raised by biological parents receive both their environment and genes from their parents, raising the possibility that genetic influences, environmental influences, and/or gene-environment interplay may account for familial resemblance. Past studies have not explored the possibility of parents' genes influencing the environment they provide (i.e., passive gene-environment correlations or "passive rGE"). If present, passive rGE is most likely to "hide" in estimates of shared environmental influences in classical twin models. The current study used a nuclear twin family design to explore the possibility of passive rGE during pre-/early puberty when past studies have demonstrated the importance of shared environmental influence. Additionally, the present study explored whether sibling-specific (i.e. influences specific to the twin generation) or family-specific (i.e., "cultural" influences within the home) shared environmental influences accounted for shared environmental influences found in past studies. Methods: Participants included pre-/early pubertal twins and their biological parents from the Minnesota Twin Family Study and the Michigan State University Twin Registry. Disordered eating (i.e., overall disordered eating, body dissatisfaction, weight preoccupation, binge eating) was assessed with self-report measures in the twins and parents. Pubertal status was determined using an established cut-off on a self-report measure. Results: Passive rGE was not indicated in pre-/early puberty. Instead, sibling-specific (not family-specific) shared environmental and nonshared environmental influences were most influential. Conclusions: Future research should explore parental influences that may impact the twin generation only (e.g., parenting style, parents' comments about weight/shape to their offspring, etc.), as this would be represented by sibling-specific environmental influences."--Page ii.
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