Stress has been linked to long term physical health and numerous indicators of wellbeing and there is increasing evidence that stress experienced in childhood and adolescence may lead to physiological changes in the brain and to disruptions in development. However, much of the data suggesting these connections are based on associations rather than on causal evidence from experiments. There are also many unanswered questions related to the relationship between stress and self-regulation, particularly with regard to the impact of social adversity during sensitive developmental periods, the variability in stress responsiveness across individuals, and the possibility for reversing negative effects. As part of a series of reports on self-regulation and toxic stress, the Administration for Children and Families asked a team at the Duke Center for Child and Family Policy to conduct a broad, cross-disciplinary examination of the literature. Following a summary of the key concepts of self-regulation and toxic stress, this brief provides highlights from that report, Self-Regulation and Toxic Stress Report 2: A Re-view of Ecological, Biological, and Developmental Studies of Self-Regulation and Stress (author abstract)