Another big plus in Empathy: Mindfulness meditation.

If you want to, use the Neurosky Mindwave Mobile headset. It's around 100$ and uses EEG to detect whether you are focused (in mindfulness mediation, called "attention"). I even think it can tell if you are experiencing empathy: Neurosky's "meditation" score seems to tilt whenever you think about anything really cute. Everything within limits of course...

Anyway, mindfulness meditation has been shown to at least appear to increase empathy. I've felt the difference too. It's way easier to "do" empathy once you have the mental muscle to stop judging and just observe. This has been shown in research as well.