Twin studies are well known for their value in quantifying the contribution of genes to population variation in behaviors and personality traits. Twin studies also provide a unique opportunity to untangle the contribution of environmental experiences to emotional and behavioral development. This is particularly true when examining monozygotic (MZ)…

This article highlights the defining principles, progress and future directions in developmental psychopathology in relation to this special section. Six fundamental principles of developmental psychopathology are identified and the pervasive impact of this integrative framework on research, theory, and practice in behavioral health fields over…