The field of behavioral genetics has demonstrated that heredity influences differences among people for many aspects of behavior, including cognitive abilities, personality, and psychopathology. However, little is known about the extent to which genetic factors influence behavioral interactions for pairs of individuals. From the perspective of child development, some of the most important interactions are those within the family, yet essentially nothing is known about such family relationships from the perspective of behavioral genetics. This research will extend into early adolescence the Colorado Sibling Study (CSS) which focuses on the social environment of familial and extra-familial relationships. The CSS has previously studied family relationships for nonadoptive and adoptive siblings in early and middle childhood. This research on early adolescence will investigate nonshared environment and genetic influence on parent and sibling relationships. This study is embedded within the long-term Colorado Adoption Project, which makes it possible to study antecedents and consequences of family relationships and to consider the role of heredity in these associations.
