In April 1994, the Rwandan president was assassinated and the country fell into chaos. Hutus began killing Tutsis. The genocide, which lasted three months, left about 800,000 dead. Laurie Anne Pearlman, PhD, a clinical psychologist and trauma expert in Massachusetts, was moved by newspaper accounts of the genocide, but she didn't know how to help.

Then, in 1997, Pearlman attended a conference on the prevention of genocide organized by her husband, Ervin Staub, PhD, a psychology professor at the University of Massachusetts Amherst. One of the invitees was a Rwandan official who talked about bloodshed he had witnessed. Pearlman told him how powerful his talk had been and he said, "Laurie, I'm here because we need your help," she remembers.

That was the call to action she needed. Two years later, she and Staub were on their way to Rwanda. Thirteen years later, they're still working there, creating radio programs designed to foster reconciliation and prevent future violence.

In 1999, Staub and Pearlman began holding trainings and workshops with the media, national leaders, and Tutsis and Hutus who worked with community organizations. To help them understand how the genocide began, Staub talked about how difficult social conditions and conflict between groups can lead to scapegoating. He discussed ideologies that offer hope for one group but may identify another group as an enemy and the escalating of violence that results. Rwanda, with its culture of respect for authority and history of victimization, was particularly susceptible, he says.

Staub and Pearlman also talked about the psychological wounds violence leaves and discussed how to prevent future violence. They stressed the importance of including all groups in the community, promoting more independence from authority and developing a shared vision for all groups. Their efforts seemed to have a positive effect. An evaluation study published in the Journal of Social and Clinical Psychology in 2005 showed that two months after one workshop, Hutu and Tutsi members of groups led by people they trained had more positive attitudes toward members of the other group. They also exhibited fewer trauma symptoms and more conditional forgiveness.

In 2002, Staub and Pearlman took their messages to a larger audience via Rwandan radio. Working with a Dutch organization called La Benevolencija, the team engaged with local writers to weave peace-building messages into a serial radio drama. Their first soap, "Musekeweya," or "New Dawn," tells the story of two villages in conflict. A year after it aired, the show had become one of the country's most popular programs. A 2009 study published in the Journal of Personality and Social Psychology found the program also spurred listeners to show more empathy toward people from other groups. Listeners also showed more willingness to express what they believe.

Staub and Pearlman have worked on similar radio dramas in Burundi and the Democratic Republic of the Congo. Staub detailed the entire project in his 2011 book, "Overcoming Evil: Genocide, Violent Conflict and Terrorism." "I have the optimistic belief that maybe we are creating social change," he says.