The crisis involving nearly 60,000 unaccompanied minors crossing the U.S. border over the last nine months has dominated the news in recent weeks.  Many of these children face fear and danger and as a result experience trauma before emigrating, during the journey itself, during their time in the U.S., and when, and if, they return to their home countries. As policymakers determine how best to address the crisis in the short term, it’s important to consider what research tells us about the effects of toxic stress on children and their long-term development.

What do we know about the kinds of stress the unaccompanied minors may experience?

Many of the children who have crossed the border are escaping trauma in their home countries, such as severe poverty and violence. While the child migrants enter the U.S. from Mexico, most children crossing the border in recent months originated from the “Northern Triangle” of Central America: Guatemala, Honduras, and El Salvador. These countries are among the most impoverished in Latin America: In Honduras and Guatemala, over one-third of the population lives on just $2.50 per day. Honduras has the highest homicide rate in the world, nearly 20 times higher than that of the U.S. The climate of violence also contributes to the region’s poverty, through wage losses among the victims and their families and through resources diverted to preventing or combating violence.

What do we know about the long-term effects of such experiences on children?

Aside from the more-immediate impacts of exposure to these events, children’s exposure to adverse experiences (e.g., exposure to violence, death of a parent, or chronic economic hardship) can trigger biological stress responses that are harmful to their current and later health, including cardiovascular disease, depression, and other chronic conditions. Adverse experiences are also associated with later harmful behaviors, such as risky sexual behaviors, drug and alcohol abuse, and perpetration of violence.

The accumulation of multiple adverse experiences can be especially detrimental to children’s well-being, which is cause for concern because for some, sources of toxic stress seem to multiply. Children living in poverty, for example, are more likely to be exposed to other adverse experiences. Living in poverty is associated with cognitive and academic struggles, and lower occupational status and earnings later in life. We also know that young people who are victimized by violence are more likely to experience depression, anger and aggression, health and substance abuse problems, suicidal thoughts, and . Yet children don’t have to be victims to be harmed by violence. Even witnessing violence is associated with anxiety, depression, and aggression, as well as cognitive and social developmental problems among children. Chronic early exposure to fear and danger may alter brain development, impairing executive functions like memory, impulse control, and focus attention.

We know what research says about the long-term risks of living in poverty and violence. We also know, however, that kids and adults can be resilient under adversity, and can develop resilience throughout their life, with policy, community, and family support that strives to provide a healthy environment for growth and flourishing. This crisis presents unique and complex problems, including immigration and humanitarian policy questions; the context of severe poverty and violence in sending regions; the conditions and treatment of children in detention centers; and the safety of repatriated children. As national and state leaders and the public work through these difficult questions, it will be important to keep this knowledge of child development front and center. Ultimately, we’re talking about the well-being of children, regardless of where they may come from.

Note: To help programs and policies better serve Hispanic children and families, Child Trends and Abt Associates launched The National Research Center on Hispanic Children and Families (Center). The Center was established in 2013 by a five-year cooperative agreement from the Office of Planning, Research, and Evaluation within the Administration for Children and Families in the U.S. Department of Health and Human Services.