Cutting is not something kids show to others, they hide it. It is something they do because they learn about it from friends. It feeds some strong needs and provides one heck of an endorphine kick.
Its addictive, and kids have a hard time stopping once they have tried it.
If you ever have the misfortune of having to deal with this, you better change your attitude.
The smart parent digs quick to find what is driving this and root it out like weeds in the garden. Then you have to watch and supervise as they find better ways of coping.
Arf arf arf, I deal with these kids...several a week! Pardon my bad attitude.
Pretty hard to supervise when your student is away at college.