Well it's definitely not good as a child to handle things way above your par grade (so to speak). It can break you and make you succeptible to quick temper and easy frustration or irrational thinking since you'd have to get a job that's totally not your responsibility done.

If you don't break and manage to endure and begin to handle the situation well, then it'll mean that you've changed. You'd have to change how you relate with people . You'd have to act like an adult so grown ups would listen and deal with you and your definitely begin to see your peers as beneath you since their thinking would be really childish to you.

But since not every home is the same, some kids are going to assume the responsibility of roles above them, especially the elderly ones in a situation were the parents are irresponsible or barely around, but still no kid should take on roles above them. It could make their childhood less fun since their childhood years would be spent being an adult.