I grew up with someone at school who literally did not understand empathy, happily stole from his classmates, but knew how to apologise with fake sincerity when caught.

His parents didn’t seem like bad people, but people who had tried both positive and negative reinforcement and it just didn’t take.

I think he learned early on in life that he could do bad things to good people, and those good people would forgive him again and again. His friends learned to distance themselves, but his family? Oh gosh, what could they even do