There is a lot of intergenerational trauma - some that gets passed down and some that doesn't. Every two people who choose to have a child bring their own baggage and chaos with them. Sometimes it's resolved, sometimes it isn't. Sometimes it can be offset by the village and sometimes it can't.

Every human being (including those who are narcissist) was still a child at some point - and it's incumbent on the rest of us not to pass judgment nor cause any further distress. We should ask questions and put up walls where appropriate. Being aware and having boundaries with people who have inherited these traits (whatever the reason) is a must.