My writing site is hereby going back up, when I get my act together. I can't live without it. I just can't. So instead, I'm going to ramble off some crap. I've asked so many people this question.
Most people say no.
It would appear that the general consensus is that no, a person is the way they are, forever and ever. That it's innate. That it doesn't change with life experiences. That even if a person makes a concerted effort to be really wonderful, they' re going to fail. Lots of people try to tell me that too.