People always get the empathy thing wrong, it`s not about ability to feel sympathy/compassion or feel emotion, damn, I can cry like a baby watching the stupidest movies lol... it`s about ability to empathize and see yourself through the eyes of others and act accordingly to that information. Most people do it unconsciously. It`s very related to theory of mind.
This is much more accurate test with more detailed results: http://rdos.net/eng/Aspie-quiz.php
You even get the picture and explanatory pdf at the end.