Deviancy amplification spiral

A deviancy amplification spiral is when something starts off small and then goes bigger and bigger until it's a much bigger problem than before. For example, let's say a group of kids at school start teasing another kid. If people keep teasing the kid, more and more people might join in because they think it's OK, and it can spiral until the teasing is out of control. If nobody steps in to stop it, it can become a very big problem.