ABSTRACT
There are some who see behavioral genetics as a field preoccupied with the estimation of heritability. Through both her example and her leadership, Sandra Scarr has done more to disabuse psychology of this ill-formed belief than any other single behavioral geneticist. Scarr was among the first to argue that the complex interplay of genetic and environmental influences was core to our understanding the course of psychological development (Scarr & McCartney, 1983). She demonstrated the utility of behavioral genetic methods for explicating the nature of both genetic and environmental influences on both human behavioral differences in general (Scarr & Weinberg, 1983) and child development in particular (Scarr, 1992). Although it has taken nearly 20 years, behavioral geneticists and developmental psychologists have both come to embrace the wisdom of Scarr’s insights. Talk of the importance of gene–environment interplay is now commonplace in both camps (Rutter & Silberg, 2002), and the rapprochement Scarr spoke of more than 20 years ago (Scarr, 1985) appears to be now upon us. In this chapter we describe a program of adoption research that has benefited greatly from Sandra Scarr’s empirical and theoretical contributions. As we hope to show, her pathbreaking work laid the foundation for a series of studies that have led us to a somewhat novel conclusion about the nature of adolescent socialization processes: Siblings may constitute a largely neglected but important influence on the socialization of adolescent deviance.
