For the sake of argument, imagine a world without conflict. That's the full-time job for members of a relatively new field called peace psychology who focus on problems like the genocide in Darfur, hatred in the Middle East, gang warfare in our cities, and rape everywhere. Wondering what lessons they've learned in the trenches that we could use in our daily lives, O asked five top peace psychologists for their best advice on waging harmony.

• "We often figure that other people see the world in the same way we do and overestimate the degree to which they understand our approach and actions. Rather than making assumptions, ask for clarification; even ask about their intention to harm you ('Did you realize when you did that, it affected me in this way?' They might not be aware of it). Be willing to take the first step in opening up such conversation. Also, when we think we'll be rejected, we tend not to smile, we make less eye contact and stand farther away. The other person may perceive these gestures as a brush-off. Go out of your way to say hello. Or smile or make eye contact. We have to take a deep breath and try to recognize that we all feel anxiety. Go in and learn."
  — Linda Tropp, PhD, director of the psychology of peace and violence concentration at the University of Massachusetts, Amherst
  
  
• "Sometimes a difference runs so deep that talking about it just won't help. In this case, having a third person present may neutralize the tension and balance the bully's power. It can be a friend of both parties. Mediation is a possibility. When both parties need to maintain a working relationship, it's useful to cooperate on a project that helps achieve a shared interest. Working toward a common goal will humanize the other person and, over time, reduce animosity."
  — Michael Wessells, PhD, professor of clinical population and family health at Columbia University and the Christian Children's Fund's senior adviser on child protection