Doctors kids become doctors and doctors are well paid.

This is anecdotal, but my elementary school class was full of doctors kids and I can tell you that the doctor parents would almost disown their kid if they didn't get into medical school. Doctors seem to have a very strong opinion on the medical field being the only right option.

So in that sense it's more of a correlation with money, and a causation through inheritance.

That is true, up to a certain extent. I'd say that at university, about half of the medical students I met had one or sometimes two parents who were doctors. The rest seemed to come from comfortable middle-class backgrounds.

In my case.... my dad is a doctor and it was sort of expected I become one myself. Its not my thing though, or it wasn't at the time so now (like a lot of people on this forum) I work in engineering. In a way I do regret it now, because I wish I did something "useful" to society.

My younger sister however, did go to med school and is about to finish. She was very driven from a young age - I don't remember her saying she wants to become anything else but a doc. When her and my dad talk, I feel a little left out and only occasionally I have the feeling they look at me and shake their heads.

Exactly. In my country it works the same way, and doctors aren't well paid here. Some of them then go to places where doctors are paid better. Thus, they don't inherit money indirectly through going to schools for well-paid professionals, they inherit profession.