Man... I'm only 23, and I grew up in New Zealand. This is really cool, but I think the parents are the main factor that needs to be dealt with regarding this general idea.
When I was 8, my dad and I built a wood + iron motorised go-kart, and then I drove it all around ours (and the next-door neighbours) property. I crashed hard, broke my arm... and it was awesome. I'm still into high-octane risk-taking fun (I'm currently working getting my solo jump license yay), but I do it as safely as possible.
I think learning risk-management is a key thing that kids are missing. I was lucky to have parents that pushed me out of my comfort zone into doing cool stuff (I trained in Taekwondo for 12 years, including 6 months in Busan, South Korea, and got my 16 year old ass kicked for the entire 6 months) -- my brothers also have grown up well adjusted to dealing with risk and excitement and danger. But others I know in my generation and below are afraid of risk, afraid of danger, and I think that's a shame...
> I think learning risk-management is a key thing that kids are missing.
I agree completely. Call it 'common sense', 'street smarts,' whatever. It's having the nous to think through what you're about to do and judge whether you're at risk of ending up in trouble, and it starts with learning the hard way that the branch you're about to stand on to climb up the tree is woefully rotted and is about to give way under you. You can't teach this stuff in classrooms, either. It's really something that has to be learned through running across a slippery piece of ground and falling over.
I still remember back when I was 6, I was playing soccer in the school grounds with other kids at lunchtime and went to slide tackle some kid. Turns out he jumped, and I didn't realise until it was too late that there were big wooden plank hurdles right behind him. I slid into them and split my eyebrow open pretty decently (I still have a patch of no eyebrow from the scar, 2 decades later).
When the school first aid room called my mum to have her come and get me, she told them that she was busy at work and I'd have to wait a bit. She knew I was alive and not going to get any worse and so knew it wasn't an emergency. Kids get hurt, it's what happens.
The other cool thing was that we had quite a bit of bushland on the school grounds and the children were allowed to play in it. We ended up forming fiefdoms and building forts and having little mock wars. It is fascinating to look back at because on top of the flagrant OH&S issues it'd raise (kids stabbing and beating each other with sticks), there was a huge political aspect to it all. Every year, you'd work out which teacher had a classroom clock that was slightly ahead of the rest, and therefore would get out to lunch slightly sooner. Those kids would be super valuable as they'd be able to run to the forts and protect their own / sabotage others freely, before the reinforcements arrived. There was serious negotiation and political power play going on amongst kids and it would've no doubt made a bunch of child development PhDs happy had they known about it.
It's hard to quantify, but I am sure that the exposure to this sort of playground environment had undoubtably a huge role in my upbringing and subsequent approach to risk and risk management in life. As such, I've been fascinated by the OP's study for a bit now and I am really glad it's being done. A lot of people talk about the problems with bubble-wrapping children these days and it's going to be good to see if it is an actual phenomenon instead of just rose-coloured reminiscence.
Mock wars: Yes! We did the same, to the point where we had diplomats and assasins, and it spread across through class-time as well. It even started my entrepreneruial spirit: I packaged up and sold "ammo" (rubber bands set up for maximum power and a small "gun" to shoot them from, tagged with a colour for your team) haha. Of course, that was very much a no-no (you'll get hit in the eye and go blind!) but it was amazingly fun and I'm pretty sure helped us understand tactics far better by applying them in the real world ;)
When I was 8, my dad and I built a wood + iron motorised go-kart, and then I drove it all around ours (and the next-door neighbours) property. I crashed hard, broke my arm... and it was awesome. I'm still into high-octane risk-taking fun (I'm currently working getting my solo jump license yay), but I do it as safely as possible.
I think learning risk-management is a key thing that kids are missing. I was lucky to have parents that pushed me out of my comfort zone into doing cool stuff (I trained in Taekwondo for 12 years, including 6 months in Busan, South Korea, and got my 16 year old ass kicked for the entire 6 months) -- my brothers also have grown up well adjusted to dealing with risk and excitement and danger. But others I know in my generation and below are afraid of risk, afraid of danger, and I think that's a shame...