I don't really know if I should be making this thread on /sci/ or /adv/ but I figured I'd ask here first to see if there's some scientific explanation behind this.

I have a increasing urge to break human bones.

When I was a kid I would broke legs and/or wings of birds and rats that I caught. (I would never kill them, though I'm sure some of them probably died a few days/hours later from not being able to move). In my teens I would use a small mallet to break the skulls and legs of stray dogs and cats and sometimes stomp on their feet to break those bones too.

From age 17 to now (25) I've done a pretty good job of containing these urges and I only hurt one dog in that period but over the last week the urges started springing up again but with people this time. I just REALLY want to break people's bones now despite never showing interest in people before. I'm particularly interested in bones in this order: arms >>> hands & wrist > legs > neck > back.

I'm not some psycho who wants to go around hurting people but I'm really scared I'm going to do it soon because it'd just be too easy for me to find some vulnerable homeless guy at night (or really anyone at all since I'm 6'5" and 200 lbs).

Is there any scientific explanation behind these urges? Please help me out /sci/, thanks.