On April 20, 1999, the halls of Columbine High School in Littleton, Colorado, reverberated with the sound of gunshots as two students, highly armed and consumed with rage, killed thirteen students and seriously injured twenty-three before turning the guns on themselves. It was the worst school massacre in out nation's history. Can we prevent a tragedy like this from happening again?

In Elliot Aronson's "Nobody Left to Hate," on of our nation's leading social psychologists argues that the negative atmosphere in our schools--the exclusion, taunting, humiliation, and bullying--played a...