Advances in understanding of the dynamic molecular interplay between DNA and its surrounding proteins suggest that epigenetic mechanisms are a critical link between early life experiences (e.g., prenatal stress, parent-offspring interactions) and long-term changes in brain and behavior. Although much of this evidence comes from animal studies, there is increasing converging evidence of these epigenetic processes in humans. These new insights into epigenetic pathways highlight the integration of nature and nurture during development and the potential for heritable changes that persist across generations.