ACEs, Resilience, & toxic stress

Learn About the Science

Due to the collective efforts of scientists and communities, we now know more about how ACEs and toxic stress affect health and human development than ever before. Here are the key concepts we use in our research on this topic.

ACEs are stressful or traumatic events that can occur in early childhood. Examples can include, but are not limited to, experiences of violence, abuse, or neglect, economic hardship, divorce, and parental substance abuse. Over time and without sufficient support, people who experience early adversity are more likely to have health problems later in life. Although there is still much to learn about ACEs, and how to prevent and mitigate their effects, we also all know that childhood experiences are not limited to those that involve adversity. In the last few years, researchers have started examining the impacts of positive childhood experiences (PCEs) on children and adults. Research has suggested that promoting PCEs for children may lead to better adult relational health and foster safe, stable nurturing relationships for children.

Resilience refers to the ability of children to withstand the negative effects of ACEs and be able to live a happy and fulfilling life despite having experienced adversity. Research shows that serious and ongoing adversity during childhood, such as extreme abuse, poverty, and neglect, can have serious effects on the developing brain and body and can contribute to negative outcomes in health and wellbeing later in life. At the same time, adverse experiences in early childhood do not automatically translate into negative outcomes. Effective services and interventions at the individual, family, and community level can reduce the negative effects of toxic stress, helping children and adults cope with, adapt to, and prevent adversity in their lives. Building the resilience and strength of our communities is one of the most important investments we can make.

A toxic stress response can occur when someone experiences strong, frequent, and/or prolonged adversity without sufficient support. The prolonged activation of stress response systems can disrupt organ development and increase the susceptibility to stress-related illnesses across the lifespan, resulting in chronic physical and mental health problems.


Bethell, C., Jones, J., Gombojav, N., Linkenbach, J., & Sege, R. (2019). Positive Childhood Experiences and Adult Mental and Relational Health in a Statewide Sample: Associations Across Adverse Childhood Experiences Levels. JAMA Pediatrics, 173(11), e193007. doi:10.1001/jamapediatrics.2019.3007

Center on the Developing Child at Harvard University. (2014). A Decade of Science Informing Policy: The Story of the National Scientific Council on the Developing Child. Retrieved from

National Scientific Council on the Developing Child. (2005/2014). Excessive Stress Disrupts the Architecture of the Developing Brain: Working Paper 3. Updated Edition. Retrieved from

Shonkoff, J. P., Garner, A. S., Committee on Psychosocial Aspects of Child and Family Health, Committee on Early Childhood, Adoption, and Dependent Care, & Section on Developmental and Behavioral Pediatrics. (2012). The Lifelong Effects of Early Childhood Adversity and Toxic Stress. Pediatrics, 129(1), e232–46.

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