Early psychosocial experiences exert a potent effect on lifelong socio-emotional well-being and health in humans and non-human primates, but the neurogenomic mechanisms are only recently emerging. Dynamic reorganization of stress pathway gene expression patterns has been documented across species following many types of early life experiences. We know that these changes may contribute to healthy and pathological socio-emotional behavior. We know less about how these changes are maintained across the lifespan. The epigenetic landscape in neural stress pathway structures and genes may play a role in some of the long-term neurobehavioral effects of early stress. I will discuss the relationships among early stress, the neural epigenetic landscape, and behavioral development in a non-human primate, the rhesus macaque. This area of research has evolutionary as well as biomedical implications. Unraveling pathways of inheritance and development will help us understand their effects at the individual and potentially even evolutionary levels. This area of research further engenders optimism that, while the epigenetic landscape may put some children at risk for poor health outcomes, it may also be one key to interventions that improve the socio-emotional well-being of at-risk children and their families.