Published online by Cambridge University Press: 19 July 2018
Although there is growing recognition that disadvantaged contexts attenuate genetic influences on youth misbehavior, it is not yet clear how this dampening occurs. The current study made use of a “geographic contagion” model to isolate specific contexts contributing to this effect, with a focus on nonaggressive rule-breaking behaviors (RB) in the families’ neighbors. Our sample included 847 families residing in or near modestly-to-severely disadvantaged neighborhoods who participated in the Michigan State University Twin Registry. Neighborhood sampling techniques were used to recruit neighbors residing within 5km of a given family (the mean number of neighbors assessed per family was 13.09; range, 1–47). Analyses revealed clear evidence of genotype–environment interactions by neighbor RB, such that sibling-level shared environmental influences on child RB increased with increasing neighbor self-reports of their own RB, whereas genetic influences decreased. Moreover, this moderation appeared to be driven by geographic proximity to neighbors. Sensitivity analyses further indicated that this effect was specifically accounted for by higher levels of neighbor joblessness, rather than elements of neighbor RB that would contribute to neighborhood blight or crime. Such findings provocatively suggest that future genotype–environment interactions studies should integrate the dynamic networks of social contagion theory.
This project was supported by R01-MH081813 from the National Institute of Mental Health (NIMH) and R01-HD066040 from the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIMH, NICHD, or the National Institutes of Health. The primary author had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. The ideas and analyses presented in this manuscript were not disseminated prior to publication. The authors thank all participating twins and their families for making this work possible. None of the authors report any conflicts of interest.