The Science of Childhood Adversity

Childhood adversity has been shown to impact a person’s life into adulthood. A history of childhood trauma has been shown to negatively impact health and behavior later in life. It even changes the way that DNA works in the body and increases risk for seven out of ten of the leading causes of death.1

The effects of adversity make childhood trauma a public health crisis—one that can be prevented.

Childhood adversity increases risk for 7 out of 10 of the leading causes of death in the United States.

Adverse Childhood Experiences (ACEs)

ACEs refer to traumatic experiences that children face in their home environment or family. These experiences include physical or emotional abuse, neglect, divorce or separation, drug or alcohol use or mental health problems.

The first research on ACES came from a 1995 study2 conducted by the Centers for Disease Control and the Kaiser Permanente health care organization. Research revealed the following:

ACEs are common. In fact, 67 percent of adults in the United States experienced at least one ACE and 1 in 4 experienced three or more ACEs.3

The impact of ACEs adds up. When people experience more ACEs, they have more negative outcomes later in life. Adults with three or more ACES have a dramatically increased risk of experiencing the following: 3

  • Heart disease
  • Diabetes
  • Obesity
  • Depression
  • Drug and alcohol use
  • Smoking
  • Poor academic achievement
  • Time out of work
  • Early death

Toxic Stress

Adversity that is strong, frequent or long-term damages the brain and body due to its repeated release of stress hormones. This is referred to as toxic stress.

When stress hits our bodies, the body increases our heart rate, blood pressure, and stress hormones like cortisol and adrenaline.4 Having this happen over and over takes a toll on a person’s physical and emotional well-being over their lifetime. This repetition harms the body and brain.

The good news is that damage can be prevented and even healed through relationships with caring adults.


Brain Development

Brain development can be thought of like building a house. To build a house that is strong enough to withstand the effects of time and weather, the house must have a strong foundation. Much like the brain, the foundation is built in the earliest stages of building a house—90 percent of brain development occurs before a child reaches the age of 5.5

Early experiences during childhood impact the brain’s development. Adverse experiences during this time create weak spots in the brain, that, when caught early, can be repaired. Left untreated, these weak spots can have lifelong negative effects.

Healthy brain development is critical to future learning, behavior and well-being.


Connection to Caring Adults

Children’s brains are built through back-and-forth interactions with their environment and other people. When infants coo, babble, gesture, or cry, they are communicating.

When adults respond to infants’ communication by talking to, comforting, hugging, and providing eye contact, they are supporting development of communication and social skills. Back-and-forth connection fosters and reinforces this development.

When adults are unreliable with their response, or do not respond in a nurturing way, the child’s development is jeopardized. Unmet needs in a child can damage or disrupt brain development and have lifelong impact on physical, mental, and emotional well-being, and can result in toxic stress responses.

Caring adults can help strengthen children’s lifelong learning and health, but even the most caring adults face many factors that impact their ability to respond supportively to a child’s needs. These factors relate to their own stress caused by financial problems, lack of social connection, relationship issues, chronic health problems, work issues, or other stress. When adult caregivers’ needs are addressed by policies and programs or other supportive means, they are more able to respond to their children’s needs and support their development.6


Executive Function and Self-regulation

Executive function and self-regulation are perhaps the most important skills in children’s development. Executive function is like an air traffic control center in the brain.7 It allows people to process a lot of incoming information at one time. Executive function allows people to stay focused and interact with the world without being overwhelmed or distracted by too much information. Self-regulation skills help to control behavior and impulses and are needed to develop executive function.

Children are not born with these skills, but they are born with the potential to develop them.

Our society has the critical responsibility of providing opportunities for children to build these skills. Without prioritizing these opportunities for children and parents, we will continue to see negative outcomes such as violence, chronic health conditions, substance use and many other conditions that are impacted by stress.

Societies see long-term benefits when they invest in the development of executive function and self-regulation in their youngest children.

Early childhood programs are an important piece of the puzzle needed to solve public health issues seen later in life. These programs vary from home-visiting programs, like Nurse-Family Partnership, where a nurse comes to the home and supports parents in their first years as parents, to community-based programs that provide opportunities for parents to connect with other parents and engage in play-based activities with their children such as those held at local libraries. Quality childcare programs, preschools, or licensed in-home and other childcare providers provide environments designed to encourage child development. In these settings, children practice their skills through play, while learning about creativity, social connection, and how to cope with stress.

  • What is executive function?

  • What is self-regulation?


Impacts of Toxic Stress

Learning how to cope with stress is a critical part of child development. When we are threatened, our stress response is activated and our bodies increase our heart rate, blood pressure, and stress hormones like cortisol and adrenaline.8 When a child has the support of a healthy, caring adult, the child can learn healthy coping skills and calm their stress response to prevent damage caused by the stress response staying activated too long.

If a child does not have the support of a healthy adult, they cannot develop the skills needed to calm their body in times of stress, and their responses may be extreme or carry on for an unhealthy amount of time. Imagine an infant who is startled by the loud noises from a thunderstorm. The infant looks to a caring adult for comfort. The way that the adult responds can either keep the infant in a stressed state or calm the infant.

Stress is a natural and sometimes unavoidable part of life. It’s important to understand the body’s three kinds of response to stress: positive, tolerable, and toxic (these do not describe the event itself).9

The Center on the Developing Child at Harvard University characterizes these responses in the following way:

Positive stress response is a normal and essential part of healthy development. It results in brief increases in heart rate and mild increases in hormone levels. Some situations that might trigger a positive stress response are the first day with a new caregiver or receiving an injected immunization.

Tolerable stress response activates the body’s alert systems to a higher degree due to more severe or longer-lasting difficulties. More severe difficulties that result in tolerable stress might include the loss of loved one, a natural disaster, or a frightening injury. If this response is buffered by supportive relationships, and limited in time, the brain and body recover from what might otherwise be damaging effects.

Toxic stress response occurs when a child experiences strong, frequent, or prolonged adversity or stress. Adversity that might result in a toxic response could include physical or emotional abuse, chronic neglect, caregiver substance abuse or mental illness, exposure to violence, or the burdens of family economic hardship. Prolonged activation of the stress response can disrupt the development of the brain and body and increases the risk for other negative outcomes.

Societies see long-term benefits when they invest in the development of executive function and self-regulation in their youngest children.


Supporting Resilience

Resilience refers to our ability to recover or bounce back after significant hardship or adversity. While some adversity can be prevented, a certain level cannot, and resilience is critical to maintain the health of a society—as a society we must reduce the effects of adversity.

Science has shown that individuals vary in their ability to bounce back from adversity. Understanding the factors that lead to a child doing well despite adversity is an important step in identifying strategies to support those at risk.

Each of us have several protective and risk factors. They are best understood by thinking about a scale with risk factors on one side, protective factors on the other. When the scale leans toward the positive, protective side, the individual is considered resilient.

The most common protective factor in children who develop resilience is having at least one stable relationship with a supportive adult or caregiver.10 These relationships provide children with opportunities to develop executive function and self-regulation, and can help children learn healthy coping skills to buffer the effects of adversity.

  • What is a protective factor?

  • What is a risk factor?

Learning to cope with a healthy amount of stress is a key factor in developing resilience. Children experience many mild stressors that can be opportunities to develop these skills. These could include having their feelings hurt, having to wait their turn to play, feeling embarrassed or excited, or losing a game. If the child has help from a supportive adult who models healthy coping skills and behaviors, they can develop their own healthy coping skills during these opportunities. Adults who focus on their own coping skills are better prepared to support children through their modeling and coaching of healthy behaviors.

  • Healthy Activities and Coping


Child Mental Health and Well-being

Children at young ages can show clear signs of mental health concerns including anxiety, ADHD, behavioral disorders, depression, PTSD, and neurodevelopmental disabilities like autism.11 Young children process their emotions much differently than adults, making these conditions difficult to diagnose.

Signs of this might include:

  • Behavioral concerns
  • Difficulty controlling or regulating emotions, intense feelings
  • Sleep disturbance
  • Difficulty concentrating
  • Self-harm or injury

Toxic stress from family relationships, persistent poverty, abuse or neglect, domestic violence, or parental mental health or substance use problems may increase a child’s risk of serious mental health problems.

Our society must address the needs of adult caregivers and families to support young children’s mental health or behavioral concerns.12 Young children’s emotional well-being is directly tied to how their caregivers are functioning and to their family environment. When relationships are abusive, threatening, neglectful, or harmful, children are more likely to experience mental health concerns. When family relationships are consistently responsive and supportive, they can buffer the effects of other stress.

Video content courtesy of the Center on the Developing Child at Harvard University


Did You Know?

Spokane Regional Health District - Early Support for Infants and Toddlers (SRHD ESIT) can help coordinate screening and assessment for children under the age of 3. If you have concerns about your child’s development, please call 509.324.1651.

For children over the age of 3, call the child’s school district for more information about available screening and services.


1 Harris, Nadine Burke. "How Childhood Trauma Affects Health Across a Lifetime." TED, September 2014. https://www.ted.com/talks/nadine_burke_harris_how_childhood_trauma_affects_health_across_a_lifetime/transcript?share=1f14dca8f7.

2 Felitti, Vincent J., Robert F. Anda, Dale Nordenberg, David F. Williamson, Alison M. Spitz, Valerie Edwards, Mary P. Koss, and James S. Marks. “Relationship of Childhood Abuse and Household Dysfunction to Many of the Leading Causes of Death in Adults: The Adverse Childhood Experiences (ACE) Study.” American Journal of Preventive Medicine 56, no. 6 (2019): 774–86. https://doi.org/10.1016/j.amepre.2019.04.001.

3 “What Are ACEs? And How Do They Relate to Toxic Stress?” Center on the Developing Child at Harvard University. Accessed January 18, 2020. https://developingchild.harvard.edu/resources/aces-and-toxic-stress-frequently-asked-questions/.

4,8“Toxic Stress.” Center on the Developing Child at Harvard University. Accessed January 24, 2020. https://developingchild.harvard.edu/science/key-concepts/toxic-stress/.

5 “Brain Architecture.” Center on the Developing Child at Harvard University. Accessed January 24, 2020. https://developingchild.harvard.edu/science/key-concepts/brain-architecture/.

6 “Serve and Return,” Center on the Developing Child – Harvard University, last modified 2019, https://developingchild.harvard.edu/science/key-concepts/serve-and-return/.

7 "Building the Brain’s 'Air Traffic Control' System: How Early Experiences Shape the Development of Executive Function." Center on the Developing Child at Harvard University, Working Paper No. 11. 2011. https://developingchild.harvard.edu/resources/building-the-brains-air-traffic-control-system-how-early-experiences-shape-the-development-of-executive-function/.

9 “InBrief: The Impact of Early Adversity on Children's Development.” Center on the Developing Child at Harvard University. Accessed January 24, 2020. https://developingchild.harvard.edu/resources/inbrief-the-impact-of-early-adversity-on-childrens-development/.

10 “Resilience.” Center on the Developing Child at Harvard University. Accessed January 24, 2020. https://developingchild.harvard.edu/science/key-concepts/resilience/.

11,12 “Establishing a Level Foundation for Life: Mental Health Begins in Early Childhood.” Center on the Developing Child at Harvard University. National Scientific Council on the Developing Child, Updated Edition 2008/2012. Working Paper 6. https://developingchild.harvard.edu/resources/establishing-a-level-foundation-for-life-mental-health-begins-in-early-childhood/.