I have said this about SIV in the past:
"Cutting can give a sense of control. I CONTROL WHEN AND WHERE I FEEL THE PAIN. "
looking at this deeper...I am pondering, this:
if as an abused child, I injure and cause my self pain, is this in someway, my young mind's attempt to stop the abuser from taking my power?
you can't hurt me, cause I already did that, you don't get to cause me pain, I already did it.
Can this be childhood logic? A subconscious attempt to preserve ones power/sense of self?
A young soul finally reaching the end of the rope, and having no other choice then to fight back, wanting to lash out at the grown up abuser but not being able too.
Is it a way for the child to take their power back? By denying the abuser the ability to take it?
Setting a back fire so to speak? (a fire set intentionally to arrest the progress of an approaching fire by creating a burned area in its path, thus depriving the fire of fuel.)
And following that line of thought to its natural conclusion....That is why SIV is so hard to give up for those who have done it for a long time. SIV now = taking back our power. And the thought of stopping SIV = giving back what little power we think we have.