I'm not sure I agree with the premise that you are either born with empathy or you aren't. Of course there are sociopaths who are defined by their lack of empathy, but they (hopefully) aren't your run of the mill job applicants.

I've always thought of myself as empathetic, but was surprised when I became even more so after a life changing event. I've spoken to many with a similar experience.

Large, traumatic events can bring the world into focus and shift perspective for those who experience them. Perhaps it's not an increase in empathy, but rather a better understanding of what really matters to me. I don't yell at the customer service rep on the phone solely because I care about their feelings, but mostly because it's simply not that big a deal in the grand scheme of things whether my internet is out or if I miss my flight. If someone I care about is in danger, I doubt I would be as "empathetic".

There's always the old adage: "You catch more flies with honey"