The importance of shared environmental influences in explaining the overlap between mother's parenting and sibling relationships: Reply to Neale (1999)

This article addresses concerns raised by M. C. Neale (1999)in his commenta ry on the D. A. Bussell et ai. (1999) Nonshared Environment in Adolescent D evelopment (NEAD) study. These concerns fall into two categories: (a) model assumptions and sample design and (b) testing of alternative models. The v alidity of the assumptions of quantitative genetic models is a concern for all researchers in this area. Discussion of those assumptions in this reply is brief and focuses on those most relevant to the NEAD sample. The two al ternative models proposed by Neale were designed to provide alternatives to the large shared environmental effect found in the original report of Buss ell et al. Because these alternative models did not provide a better fit, t he appropriateness of Bussell et al.'s basic model and the importance of sh ared environmental influences for explaining the association among family s ubsystems are supported.