Stopping a teen bully seems like it should not be complicated. In the movies, all it takes is a single act. Another teen just has to step up and say, “Hey, that’s not okay.” But in real life, it is often not so simple to embrace our inner heroes. Friends may suddenly decide not to help. They may even worry about becoming the next victim. What makes a teen more likely to intervene when they witness bullying? A supportive school with trusted teachers and clear guidance from a kid’s family both help. That is the finding of a new study.