Where does malice come from?

Where does malice and paranoia come from on the BPD spectrum.

What goes as input comes out as output. I was bullied, berated, laughed at as a kid, so I am rude to others in real world. At least I was before I came to this forum.

If you are angry towards a kid all the time, you're teaching him anger. It turns to rage in me, cause I have impotent anger that I couldn't stand up to my bullies in the past and now I can't do anything.

This is where malice comes from, seeing others happy with happy childhoods(or so they say) as compared to mine.

As far as paranoia, I don't trust people. I'm very sensitive to criticism, and most nons joke around all the time. If I don't trust people, why hang out with them.

For me it's thinking other people are malicious. I'm not malicious myself. To me, "malicious" implies there was intent to do ill by someone else.

I guess some BPDs can be manipulative though (but not malicious), often unwittingly by throwing a tantrum when upset, but general the ones who murder or violate people's rights in some way also have traits of psychopathy or ASPD. Sometimes NPD as well. I find it hard to believe the Jodi Arias, for example, was just borderline. Does she display some borderline traits? Yes. But her sense of entitlement turned to violence against someone else rather than herself, which is more consistent with one of the other disorders in cluster B, and of the malignant variety at that.