Let's talk about empathy: what is it, why do we have it and how do you use it?

I have been increasingly fascinated by the way in which empathy shapes our world view and how we behave . Is it a strictly human condition? Do unto others? Gender based? What about the Trolley Problem? Is this what fuels sites like GoFundMe?

Elon Musk had some personal views on this that had me pondering his behavior:
https://www.npr.org/2025/03/22/nx-s1-5321299/how-empathy-came-to-be-seen-as-a-weakness-in-conservative-circles
Empathy versus Sympathy:
https://www.youtube.com/watch?v=khitCEJHzH4
The Golden Rule:
https://youtu.be/CU3LgRcHWfg

Okay, it's a tricky concept but let's bat it around a bit and see what turns up.