By "empathy", I mean the ability to pick up on another's feelings and vicariously experience them yourself.
I know that someone's experiences as a child have a huge effect on their development (or lack thereof) of the capacity to emotionally connect with others and feel compassion in response to suffering. By adulthood, when our brains no longer have the same degree of plasticity, are traits like empathy and compassion pretty much set?
My guess: It's possible for a person to moderately improve their ability to empathize, but it's difficult, and for many, unlikely to actually happen. The deeply-ingrained emotional barriers that prevent someone from letting others' feelings affect them don't come down as easily as they went up. People do change their behavior all the time, but it seems so much more difficult to alter how you emotionally respond.
But, I'm not sure, so I'm asking you to share your opinions.