Even if it came to an intruder, I don't think I would naturally become violent. The only time I though I had an intruder was when I still stayed at my mams and I was home alone. I thought I heard my OH come in and come up the stairs as we were going out.. After about 2 mins I realised he hadn't made an appearance, so I went downstairs to see where he was..As I came downstairs there was the loudest crash from the living room.. My gut reaction was to run. I remember running so fast down the hall that I could hear the wind in my ears, managed to get myself into the toilet and lock the door.. I was whimpering, shaking and couldn't breath.. Then it dawned on me that my hips were too wide to get out the small loo window, which had been my plan! I opened the door without making a sound, got the phone and locked the door again.The pub next door got a mental, whispery message telling people to come quickly.. My OH and his friends appeared seconds later to "save" me. Turns out my intruder was just a mirror falling off the wall
So, I don't think violence come naturally to people even in panic and when you think you're in danger.
Again though, it would be a different story if somebody was trying to get to my kids.