Like Father, Like Son

A couple of classes ago, we discussed parents, children, and careers. More often than not, children will end up following relatively the same career path as their parents. This probably started years and years ago, where if your parents were farmers (for example), you would inherit the farm and become a farmer.

Nowadays, even with all sorts of careers available, kids tend to follow the examples that their parents set. Even if they don't have exactly the same career, it is usually influenced by what their parents did.

My question is this: Let's say there's a kid who has a perfectly good relationship with both of his biological parents, but goes into a completely different career field than both of them. Who influenced this child? Was it nature or a nurture outside of his family?