Can kindness be learned or cultivated, and to what extent is it an innate quality?

Kindness can be learned. The difference between being genuinely kind and just constantly successfully mimicing what a kind person would do is - no difference at all, really.

Ultimately, I think people who started as natural assholes make the best kind people - beacuse we don't just do what feels kind, but we have to examine the results of our attempts at kindness, and adjust if needed.