In a lot of U.S. states now, the age is as high as 12. The U.S. has gone absolutely insane in the name of protecting children. And, if you dare question the wisdom of any of these policies, you're typically met with something like, "I guess you just want children to DIE".
As an aside, there's also this creepy trend in the U.S. to refer to 15 and 16 year-olds as "children". If someone had referred to me as a child at 16 years old, I would have looked at them like they were insane.
The rational answer is that you absolutely can send your children to play in the park.
Why don't people do this then? In the U.S. in most states, leaving children unattended even close to home for any amount of time is considered a form of neglect or abuse, though the precise wording varies by state and the age of the child.
The risk is that if the police pick up your kid or if the state department of child and family services catches wind of this, they can take your children from you and you have to go through a very unpleasant process to get them back, after which there are mandatory home visits by the state.
Sadly, this happens more than it should since the laws in most states are very vaguely defined and the police and state employees at the department of child and family services are given extremely wide latitude in these situations. In some states the precise age at which you can leave children unattended isn't even explicitly defined; the interpretation "too young to be left alone" is left to the police or the state agency that handles these types of things.
The most common victims are the working poor who sometimes will leave children unattended because they have to work and either can't afford or can't find childcare.
It's a really bad situation on many levels, and for some reason there hasn't been a serious effort to reform a lot of these issues. I know the whole thing must sound absolutely crazy to anyone outside of the U.S. but it really is how things work in most places here.
When we moved into the neighborhood we went door to door introducing our children and handing out copies of Playborhood[1] with our phone number written inside the cover to each of our neighbors. If no one in your neighborhood calls the police when they see your kids walking to the park the chances of a negative interaction go way down.
Just one small local step towards reform, so far it has worked out well for us.
This seems shockingly dumb. I wasn't aware of such things going on in the US, my cultural knowledge on the subject of growing up in the US was of kids roaming around on their bikes all day.
Kids roaming around on bikes was the norm in the U.S. for a long time. It started changing sometime in the mid-nineties and has been getting progressively worse since then.
There are some glimmers of sanity emerging though, but it's very nascent. This org in particular is doing some good work: https://letgrow.org/ - there are also some stories on the site that explain things much more eloquently than I have.
I'm now curious if this links to the childhood obesity epidemic in the country.
edit/ I just saw another comment you made that suggests that it does. I wonder then if the "free-range parenting" legislation in Utah, Texas, and Oklahoma has made a difference.
As an aside, there's also this creepy trend in the U.S. to refer to 15 and 16 year-olds as "children". If someone had referred to me as a child at 16 years old, I would have looked at them like they were insane.