My research asks how ordinary people come to take part in violence, and how they come to refuse. Three themes organize the work.
 

The first is defection: how someone who has participated in or otherwise supported state violence turns against it and begins saving lives. These reversals are common in the historical record and poorly explained by theories that treat killers and rescuers as different kinds of people.
 

The second is boundaries: how the lines people draw between "us" and "them" (racial, ethnic, religious) make mass violence possible, and how violence in turn redraws those lines, hardening categories that were once fluid and leaving divisions that outlast the killing by generations.
 

The third is moral judgment in the moment: how people actually decide, under pressure and uncertainty, what is permissible. My work here has revised a common assumption about dehumanization, showing that seeing others as less than human often follows violence rather than causing it — which changes what prevention should target.

To view my publications, please click here.