When Is Stress Good for Kids—and When Is It Toxic?

What if the stress some young children experience leaves a lasting mark, shaping not just their minds but their biology? Imagine stress inscribing on their genes, rewriting the way they grow and respond to the world. This isn’t just an idea—it’s backed by groundbreaking science that shows how early stress can “get under the skin,” influencing health and well-being for years to come. But when is stress insidious and toxic, and when does it build strength and resilience?

Sensitive Periods and Stress

Stress is a part of life, and not all of it is harmful. In fact, some stress is essential for growth. This “positive stress” might look like a baby crying for a caregiver and finding comfort when the caregiver responds. These moments of stress reactions and resolution build resilience at the biological level, helping children develop appropriate stress responses.

Sometimes stress is more intense. Tolerable stress comes from harder situations, like losing a loved one. When a child is surrounded by supportive relationships and a safe environment, even serious stress can be managed in a way that avoids harmful effects on the child’s health. I’ve written about resilience and the ways in which positive adaptations can help children to buffer against some kinds of stress, making it tolerable for children.

But then there’s toxic stress. This happens when children face ongoing adversity—like neglect, abuse, or chronic exposure to violence—without the support they need. Toxic stress overwhelms the body and brain, disrupting the systems that regulate emotions, learning, and even physical health.

Scientists now know that this type of stress doesn’t just pass through us—it can change us, altering the way our genes work through a process called epigenetics. Particularly during sensitive periods - from birth to about age three - the impact of toxic stress can ripple out into the future, increasing the risk of chronic illness, mental health challenges, and more.

My Insights: The Lasting Reach of Toxic Stress

Toxic stress can shape a child’s development in ways that ripple out across their entire life. Research by Rebecca Reh and her team (2020) shows how stress can even pass from one generation to the next, as the biological effects of adversity are carried through gene expression. This means that a child may inherit their parent’s stress response.

What’s more, children’s bodies often adapt to stress in ways that may help in the short term but come at a cost. For instance, girls who experience toxic stress may begin puberty earlier—an adaptation that might have supported survival in a harsh environment but today leaves them vulnerable to health risks like obesity and heart disease.

Not all children respond to adversity in the same way. Research by Boyce et al. (2021) shows that a child’s reaction depends on their unique combination of genetics, environment, and the timing of stressful experiences during development. Tailored approaches that consider each child’s specific situation and developmental stage are the most effective way to build resilience and support well-being.

Some experts argue we should shift how we think about stress altogether. Ellis et al. (2017) propose that instead of focusing only on the damage caused by adversity, we should see stress as something that can also foster unique strengths. For example, children who grow up in difficult environments often develop special skills, like being highly alert or making quick decisions—abilities that help them adapt to their circumstances. The authors suggest that we shouldn’t try to “fix” these stress-adapted behaviors but instead find ways to use them as strengths. For instance, schools could help children apply these abilities to broader contexts, turning them into tools for success. This strengths-based approach focuses not just on challenges but also on the potential for growth and resilience.

While I am an advocate of this reframing of stress, I’m particularly inspired by Dr. Hensch’s work on reopening critical periods in brain development that offer promise for severe cases. The brain’s remarkable ability to adapt and rewire—its plasticity—means it’s never too late to help children and adults heal from the long-term effects of toxic stress. The brain is particularly plastic during “windows” called sensitive periods in early childhood and adolescence. If scientists can one day reopen these windows, we could help repair the harm caused by early stress and even break cycles of adversity across generations.

Research Spotlight: Dr Hensch on Pruning and Plasticity

Key Takeaways for Practice

1. Act Early, But Don’t Lose Hope
   Intervene early to reduce the effects of toxic stress, but remember that the brain’s plasticity means healing and growth are possible at any age.

2. Supportive Relationships Are Key
   Stable, nurturing relationships can shield children from the harmful impacts of stress, helping them build resilience and healthy stress responses.

3. Focus on Strengths, Not Deficits
   Children who adapt to stress often develop unique skills, like quick decision-making. Once out of harm, interventions should build on these strengths rather than trying to “fix” them.

Engage With Me

I would love to hear your thoughts on this topic! Here’s how you can get involved:

• Schedule a Meeting: Put time in my calendar here to discuss any topics further 

• Group Zoom Meetings: Interested in a deeper dive? Let me know, and we can organize a group discussion.

• Email Suggestions: Email me with questions, thoughts, or a topic you want me to cover in future newsletters.

• Please take 30 seconds to respond to this poll: that way I can keep improving the newsletter for you.

Join Us on This Journey

This exploration of topics in early childhood is for anyone with a deep interest in development, education, technology, and media. Whether you're a donor, educator, partner, or practitioner, there’s valuable insight here for you. Together, we can collaborate, learn, and make a lasting impact.

Thank you for being an integral part of this journey. I’m excited to continue this exploration with you!

Tanyella A. Leta