Despite the expansion of bully-proofing programs in recent years, many teachers feel they lack the training necessary to manage the complexities of friendship at work in the classroom and on the playground. Teachers want their students to be friends and to be kind to each other. The reality is, all children have moments in which they are unkind. As counterintuitive as it might seem, children's "meanness" actually serves an important and useful function in the development of their social skills, compassion, and empathy. Children learn over time to channel their feelings of competitiveness, jealousy, and aggression more constructively. Understanding why mean behavior happens in the classroom can help a teacher do a better job of preventing it. Instead of simply punishing students, recognize and welcome what students are attempting to do as they learn friendship skills, and then guide them to express their desires more appropriately.