The relationship code

"The Relationship Code presents a unique theory of genetic influence while highlighting the social processes in the family that are of great importance for adolescents. These ideas, which will refresh our conceptions of psychological development, are based on the analysis of a twelve-year longitudinal study of the influence of both family relationships and genetic factors on adolescent development. The sample consisted of 720 pairs of same-sex adolescent siblings and their parents. The pairs included six different sibling types of differing degrees of biological relationship, from monozygotic twins at one extreme - siblings who are genetically identical - to genetically unrelated step-siblings at the other."--BOOK JACKET.