It definitely depends on the kid, and it definitely depends on the length of time. I think there's a huge difference between while I'm running to the corner store for milk and a whole afternoon, much less all day. If it's for more than a few minutes, I'd want to make sure the child is mature enough to remain calm and act appropriately in an emergency. If it's just a few minutes, then I'll be back really soon so it's not as much of an issue, yk? Then it's more just about being responsible enough not to do something really stupid just because I'm gone.
