Genetic and Environmental Influences on Maternal and Sibling Interaction in Middle Childhood: A Sibling Adoption Study.

Genetic and environmental influences on maternal and sibling interactions were examined in 67 mother-child-child triads from nonadoptive families and 57 mother-child-child triads from adoptive families (in which both children were adopted and genetically unrelated). Triads were videotaped in 6 play settings in their homes. In addition, each sibling pair was observed in an unstructured setting in the home, and mothers completed an interview about the sibling relationship