Abstract
Social experiences occurring during infancy have been demonstrated to exert persistent effects on neurobiological and behavioral outcomes. This social modulation of the developing brain has been observed in humans and animal models of abuse, neglect, and variation in parental style. Although the mechanisms through which these effects are achieved likely involve diverse cellular and molecular pathways, there is emerging evidence supporting the hypothesis that epigenetic changes, such as DNA methylation and histone modifications, may mediate the effects of early life variations in the social interactions between mothers and infants. Moreover, there may be plasticity within these epigenetic pathways at later developmental time points, such that the social experiences of juveniles and adults may also induce epigenetic change. These findings have implications for behavioral variation observed both within and across generations and highlight the dynamic interactions occurring between genes and environments during the course of development.