I'm interested to see if you have any links to studies/research that back this up.

The reason I ask is that I personally find I am passionate/hardworking for certain things but for others I'm completely disinterested/lazy.

Likewise I have seen other people who are typically lazy and not hardworking, but get them on the one thing they are interested in (e.g. a specific sport) and they can quote match and player statistics stretching back decades. It's like they have this amazing ability but they've only applied it to a relatively useless part of their life (I say relatively useless because if they'd applied themselves with the same fervour to their work they'd have a much better quality of life).

I'm not sure how that connects that with genetic personality traits.