Provides an introduction to a special section on developmental behavioral genetics (the study of genetic and environmental influences on individual differences in behavioral development), discussing the potentialities of the interdiscipline and presenting an overview of the following articles. (Author/RH)

Reviews research on the heritability of intellectual factors, personality factors, and psychopathology. Discusses the importance of investigating within-family environmental differences in order to understand the environmental origins of individual differences in development. (Author/BJV)