Data point: I live in a neighborhood that's overrun with kids who are minimally and relaxedly supervised, and that's absolutely going to be a factor in when and how we let Kit roam without us once they're old enough to do so. It's one of the reasons I love it around here. A key thing, I think, is that it's a poor neighborhood that hasn't gentrified, so everyone's too busy trying to scrape together a living to be the nosy busybody sort who calls the cops on a child left unattended for three! whole! seconds! Lots of kids playing outdoors also means lots of adults getting to know all the neighborhood kids, too. Every time Kit goes out front with a bucket of chalk, children run over from three houses in either direction to draw with them. Within another few years we'll be on first-name terms with everyone on the block.

Our downstairs neighbor, L, has a child who doesn't live with him but visits periodically in the summer; the kid, whose name I never manage to catch, is about seven and really likes playing with Kit. L encourages him to play on his own in front of our house and periodically glances out through the open door to check on him. At one point my partner and Kit wandered around the corner and L's kid followed them while I stayed hanging out on our front steps. The next time L came out, he looked a bit alarmed to see no seven-year-old there, but I said "He's around the corner with Josh and Kit" and L nodded and relaxed and went back inside. We never discussed that we feel like whichever adult is around is responsible for all the kids; that's just how it is. And it's how it is up and down our entire street.

I was a city kid who was running errands to the supermarket three blocks away as soon as I was old enough to safely cross streets on my own—maybe age seven or eight?—and taking the subway alone by the time I was 12. All this alarmism about unsupervised kids is so weird to me.