We evaluate the usefulness of 11 key epigenetic concepts from the behavior genetic research paradigm for advancing the field of developmental psychopathology. Key assumptions, empirical examples, and caveats in interpreting results are presented. We emphasize the usefulness of incorporating both dimensional (e.g., temperament trait) and categorical (e.g., diagnosis) variables, environmental measures, direct behavioral assessments, and multiple, theoretically relevant occasions of study into classic twin and family studies. We highlight contemporary techniques for identifying specific chromosomal regions associated with behavioral patterns, and the importance of considering nonmendelizing genetic influences when discerning the panorama of genetic influences on behavior.