Behavioral Genetics and Aggressive Behavior in Childhood

Abstract

Behavioral genetics has contributed to the study of psychopathology in three ways: (1) It has provided a theory of the genetic and environmental origins of individual differences in behavioral pathology, (2) devised methods that can disentangle the influence of nature and nurture, and (3) produced data that converge on the conclusion that hereditary influences are important in psychopathology. The new subdiscipline of developmental behavioral genetics is particularly relevant to the field of developmental psychopathology because its focus is on genetic change as well as continuity during development (Plomin, 1986a). The purpose of this chapter is to introduce developmental behavioral genetics, using aggressive behavior in childhood as an example of this approach. "The addition of a Y chromosome to a normal male chromosome constitution does not produce a discernible phenotype. Males with 47,XYY cannot be characterized by discriminating physical or behavioral features. The first diagnosis of this condition, therefore, was a karyotypic and not a phenotypic discovery. Pubertal development is normal and these men are usually fertile."