Can't remember but i babysat from 14 for neighbours and friends. As the oldest girl in a largish family i remember looking after my siblings from a very young age and being left alone for a half hour/hour from about 12 onwards. My parents weren't out partying. it's just it was assumed we were safe enough. We were friendly with all the neighbours so if anything went wrong we could ran over there. Mind you i grew up in the country where from a young age we would go off by ourselves on the bike or to the woods. My parents didn't worry because they thought we were safe enough. Neighbour's kids did the same. Different time then when people didn't even think of certain things happening. I don't think i'd be so free if i had children but i don't think they should be too smothered either. I think 16 is ok personally.