Just found this now. It's an interesting topic.
For me, I remember my empathy was a lot more...naturally occurring before my trauma, and after I was sexually assaulted, I had trouble empathizing with men in particular...I just hated them, and I hated that I hated them all, but I did.
I used to have a much harder time shutting off empathy before my trauma, and after, when I started my journey into recovery, I think I was just too numb to my own feelings, and too caught up in daily reality being so harsh and fighting off urges to hurt myself, that I just wasn't capable of feeling anything for anyone, or even appreciating anything about anyone else.
I once prided myself on being able to appreciate everyone, and then suddenly it was as though they were all just characters in a video game like pac man and I was the pac-man trying not to be eaten by the jelly creatures.
I guess what I'm trying to say is that my ability for empathy has changed at different times, and so has my ability to control it, turn it off consciously. I used to take on other peoples physical pain, especially when giving massages, and that seems to not be the case anymore, so maybe I'm gotten better at turning it off?
I feel glad now that I can actually have empathy for people at certain times. It makes me feel human again. I didn't have that for a long time. Even when the world trade centre came down, it was like it was so far away and all that mattered was my own survival. I know that sounds self-centred, to an extreme degree, but I was really traumatized at that time, and I just couldn't expose myself to any other tragedies going on. I didn't have the resources to deal with it, and as I said, it seemed so surreal to me, and I felt so alienated at the time...I just didn't feel anything, except bad, like I was uncaring for not caring.
I did realize that I just had to shut down at the time, for my own survival.
I still had the normal shock reaction when it happened, and I do recall being able to guess how the people jumping out the windows "must have" felt, but I didn't actually feel them!