[ineedausername]

> I've seen racist/bigoted people become genuinely less bigoted over time

I've never seen this, and I won't be fooled if I do see it as it will be temporary/circumstantial I think.

> How does this make sense if people are immutable?

We aren't entirely immutable but I find it challenging to draw the exact line.

People can and do become more narcissistic in a pathological sense, you get into contact with such traits from your environment, you eventually contract the decease.

That doesn't mean you can change who you are in any meaningful way, it's just that (even unconsciously) adopting narcissistic traits is now in effect a positive adaptation (higher chances of becoming more "successfull" etc).