IIRC studies about career choice imply that "doctors produce doctors, lawyers produce lawyers" is somewhat true, however, not because ability (there was no evidence that there's much specialized ability, someone who has the qualities where they're likely going to be a good doctor is also likely to be a good lawyer and vice versa), but because career choice is highly influenced by the options you consider, by the choices that seem "normal" in your community, and that is highly influenced by having parents/relatives in that field.