The authors address the methodological, theoretical, and ideological criticisms of their article on adolescent perceptions of parenting behavior made by G. Greenberg and T. Partridge. Behavioral genetic methods have provided unique insights on the origins of individual differences in behavior and, when applied to parenting and other putative psychosocial influences, challenge conventional developmental theory. McGue et al.'s goal was not, as Greenberg and Partridge appeared to believe, to establish the heritability of parenting--that was already known; rather, McGue et al. showed how the relationship between inherited factors and an individual's environment changes during a critical developmental transition. There is a great need for developmental researchers to explore the combined influence of genetic and environmental factors using a range of approaches, including that of McGue et al.