I don't have a clue about the causes of all those things. I only know about cutting, which (in my own case) developed out of severe depression, dissociation, and generalized anxiety disorder. It's a coping mechanism, and one that I recognize as unhealthy. My pdoc and t explained that one resorts to self-injury when one's usual coping mechanisms have been exhausted.

I can't imagine why anyone would be boastful about it.