From large-scale wars, natural disasters, and pandemics to community-level religious and ethnic conflicts, many leaders wield power during crises by championing their group’s goals against those of rivals. But there is also a rarer breed of leader—barrier-crossers who pursue group interests by recognizing rivals’ interests and working with them to achieve mutually beneficial outcomes. Though such leaders have played vital roles in resolving conflicts, little is known about their extraordinary motivation. Here we report survey results contrasting barrier-crossing with barrier-bound leaders from seven communities. In line with new theories from group psychology and anthropology, we found that barrier-crossers uniquely reported intense, family-like bonds to both ingroups and outgroups. Further evidence suggests that these outgroup bonds result from past, personally transformative experiences shared with outgroup members