When mummy and daddy get under your skin A new look at how parenting affects children's DNA methylation, stress reactivity, and disruptive behavior

Child maltreatment is a global phenomenon that affects the lives of millions of children. Worldwide, as many as one in three to six children encounter physical, sexual, or emotional abuse from their caregivers. Children who experience abuse often show alterations in stress reactivity. Although this alteration may reflect a physiological survival response, it can nevertheless be harmful in the long run-increasing children's disruptive behavior and jeopardizing their development in multiple domains. But can we undo this process in at-risk children? Based on several lines of pioneering research, we hypothesize that we indeed can. Specifically, we hypothesize that highly dysfunctional parenting leads to an epigenetic pattern in children's glucocorticoid genes that contributes to stress dysregulation and disruptive behavior. However, we also hypothesize that it is possible to "flip the methylation switch" by improving parenting with known-effective parenting interventions in at-risk families. We predict that improved parenting will change methylation in genes in the glucocorticoid pathway, leading to improved stress reactivity and decreased disruptive behavior in children. Future research testing this theory may transform developmental and intervention science, demonstrating how parents can get under their children's skins-and how this mechanism can be reversed.