Peacebuilders working with families in conflict zones often witness how trauma passes down through generations. Yale Jackson School anthropologist Catherine Panter-Brick presented scientific evidence showing how war trauma can alter gene expression and affect future generations. She described her findings at a high-level session on early childhood development and peacebuilding during the 80th United Nations General Assembly on September 25, 2025.

“Violence leaves its mark on the human genome across generations,” said Panter-Brick, “which tells us that the legacy of war is not only social and psychological – it is biological.”

Panter-Brick, the Bruce A. and Davi-Ellen Chabner Professor of Anthropology, Health, and Global Affairs, joined fellow Jackson School faculty member Bonnie Weir at the session hosted by Ireland’s Permanent Mission to the United Nations. The gathering came at a critical moment—grave violations against children in armed conflict surged 25% in 2024, the worst year since monitoring began in 2005.

As part of the “Voices of Science” panel, Panter-Brick presented findings from her first-of-its-kind study on war and epigenetics among three generations of Syrian refugee families. The research, published in Scientific Reports in February 2024, found that women who experienced the violence of war during pregnancy showed altered epigenetic markings—and so did their children and grandchildren, even those who had never been directly exposed to conflict.

Panter-Brick described the epigenetic changes as a “dimmer switch”—violence does not rewrite DNA but can turn gene expression up or down, affecting cellular memory and child development in ways that last generations. The research identified 32 sites showing this common epigenetic signature of violence across germline, prenatal, and direct exposures.

While violence alters a child’s developmental trajectory in ways that last a lifetime, researchers know that investing in children and families is an effective pathway to peace.  “Early life sets the stage for who we are,” said Panter-Brick as a reminder. The science shows that programs that effectively support families, parents, and children in early life build resilience, reduce violence, and create conditions for lasting peace—making them among the most empirically grounded tools for addressing intergenerational cycles of conflict.

The Irish Permanent Mission’s sponsorship was especially fitting: for Ireland, the science confirms lessons learned through experience. For over 25 years, the Irish and British governments and the European Union have invested in early childhood development programs across Northern Ireland and border counties to mitigate these intergenerational effects—programs that built pathways from divided communities to lasting peace by supporting families across generations.

As Ireland approaches the 30th anniversary of the Good Friday Agreement in 2028, Irish representatives at the session emphasized how much they valued the work done with children to interrupt cycles of violence—and recognized Yale’s scientific contributions and approaches to peacebuilding.

Nuala Ní Mhuircheartaigh, Ireland’s Deputy Permanent Representative, opened the session. Ambassador Fergal Mythen, Ireland’s Permanent Representative who has extensive experience supporting the Northern Ireland peace process, delivered closing remarks alongside Archbishop Gabriele Caccia, the Holy See’s Permanent Observer to the United Nations, and Franz Hartl, associate director for digital experience at Yale and an Executive Committee member of the Early Childhood Peace Consortium.

Weir, senior lecturer, assistant dean for undergraduate education at Yale Jackson School, co-director of the Human Rights certificate, and founder and co-director of the Peacebuilding Initiative at Jackson, highlighted the session’s unique integration of research and practice.

“Often, events focusing on stopping violence against a particular, vulnerable group—in this case, children—are, of course, compelling, but don’t provide concrete, practical ways that scholars and policymakers can help,” Weir said. “The event at Ireland’s permanent mission to the U.N. integrated discussions between practitioners in the field and academics, suggesting some promising approaches to mitigating violence and its nefarious, enduring effects on children.”

The session brought together researchers from Yale, Boston College, and NYU with practitioners from Türkiye, Palestine, and other conflict-affected regions. Dr. Najat Maalla M’jid, the UN Special Representative on Violence Against Children, delivered the keynote address. The gathering generated significant momentum around scaling early childhood development programs as a pathway to sustainable peace.

The session also launched the Early Childhood Peace Consortium’s Five-Year Strategic Plan (2025-2030), demonstrating how evidence-based early childhood development programs have successfully reached millions of children across countries including Bangladesh, Brazil, Colombia, Lebanon, Rwanda, and South Africa.

Panter-Brick directs the Conflict, Resilience and Health Program at Yale’s MacMillan Center for International and Area Studies and is co-director of the Peacebuilding Initiative. The epigenetic research, co-led by Professors Rana Dajani (Hashemite University), Connie Mulligan (University of Florida), was funded by the MacMillan Center and the National Science Foundation. A short video highlights the main findings.  The study builds on evidence from a randomized control trial showing that brief, well-designed interventions effectively alleviate stress and trauma in the wake of war.

In the photograph: Bonnie Weir (L) and Catherine Panter-Brick (R) with Ambassador Fergal Mythen at Ireland’s Permanent Mission to the United Nations, September 25, 2025.